Often asked in vivas, ophthalmic eponyms or various signs/ instruments in ophthalmology which share the same name, are one of the favorite questions of many examiners. We have tried to compile common such terminologies in ophthalmology for the benefit of postgraduate students.

A

Amsler (Marc Amsler : Swiss ophthalmologist, 1891-1968)

• Amsler Grid- The Amsler Grid is a square-shaped grid used to detect or monitor metamorphopsia or scotoma involving the central visual field in various disorders of the macula and optic nerve head.There are 7 charts of the Amsler Grid each with a dimension of 10 cm × 10 cm.
• Amsler sign- Amsler sign (aka Amsler-Verrey sign) is present in Fuchs heterochromic uveitis (FHU). It is characterized by hemorrhage in the anterior chamber (hyphema) after anterior chamber paracentesis or entry with the micro vitreoretinal blade during anterior segment surgeries, including cataract surgery or minor trauma.
• Amsler Krumeich grading- Classification of keratoconus based on mean K-readings on the anterior curvature sagittal map, thickness at the thinnest location, and the refractive error of the patient.
• Amsler dubois chart- standard fundus chart, Amsler–Dubois chart, which contains three concentric circles – the innermost circle represents the equator, the middle circle represents the ora serrata, and the outer one is the junction between the pars plana and plicata.

Anderson (Douglas R Anderson : American Ophthalmologist 1912-1996)

• Anderson’s criteria- Andersen's criteria for glaucomatous field defect: These criteria (in relation to a Humphrey printout only) are helpful in the diagnosis of early glaucoma and are as follows:
  • • Abnormal GHT
    • Three or more non-edge points of the 30-2 printout, contiguous and with a P < 5%, out of which at least 1 has a P < 1%
    • CPSD should be abnormal and should have a P < 5%
• Anderson's rule - Andersons rule says that when naevus flammus involves the upper lid, there is ipsilateral intraocular involvement.
• Anderson’s theory (primary congenital glaucoma)- Anderson proposed that excessive or premature accumulation of collagenous beams within the trabecular meshwork inhibit posterior sliding of the ciliary body and peripheral iris, leading to anterior insertion of the iris root and ciliary muscle, which can obstruct the trabecular meshwork, and narrow or completely compress the Schlemm canal.
• Anderson-Kestenbaum surgery- this procedure done for infantile nystagmus shifts the null point centrally and reduces the head turn. The right lateral rectus and left medial rectus muscles are recessed. The right medial rectus and left lateral rectus muscles are resected.

Arlts (Carl Ferdinand von Arlt: Austrian ophthalmologist, 1812–1887)

• Arlt's Line- Horizontal, linear scarring of the upper tarsal conjunctiva. A classical sign of trachoma.
• Arlt's Triangle- keratic precipitates distributed in a wedge-shaped area on the inferior corneal endothelium in the case of uveitis. The pattern occurs due to convection currents of aqueous humour.
• Arlt’s surgery- Transplantation of eyelashes back from the edge of the eyelid for treatment of distichiasis
• Arlt’s syndrome- A name used for Trachoma. A contagious infection of the eyes, characterized by keratoconjunctivitis with pannus, papillary hypertrophy, follicles, and scarring, often leading to blindness.
• Arlt’s enucleation technique- The classical enucleation technique of Arlt is where the conjunctiva is incised around the periphery of the cornea and dissected back, in fact deliberately turned back so as to expose the tendons, which are raised on the scissors and snipped in the succession, of one lateral and then two recti in the vertical plane preceding the nerve section.

Arden (Geoffrey Bernard Arden : British Ophthalmologist 1930- 2018)

• Arden’s Ratio- The Arden ratio, the ratio of the Light peak (Lp) to the dark trough (Dt) in electrooculogram. An Arden ratio of 1.80 or greater is normal, 1.65 to 1.80 is subnormal, and < 1.65 is significantly subnormal.
• Arden’s plates- The Arden grating test is a subjective clinical test of visual function introduced in a portable book form by Arden and Jacobsen in 1976. The principle of the test is the measurement of contrast sensitivity by sine-wave gratings. A standard set of 6 plates in book form were used under controlled illumination conditions. The visual threshold for the gratings was measured for each of the 6 different spatial frequencies.

B

Bells (Sir Charles Bell : Scottish anatomist, surgeon, and physiologist, 1774- 1842)

• Bell’s palsy- Bell's palsy, also known as idiopathic facial palsy, is a form of temporary facial paralysis or weakness on one side of the face. It results from dysfunction of cranial nerve VII (facial nerve) which directs the muscles on one side of the face, including those that control eye blinking and closing and facial expressions such as smiling.
• Bell's phenomenon- Bell's phenomenon (also known as the palpebral oculogyric reflex) is a medical sign that allows observers to notice an upward and outward movement of the eye when an attempt is made to close the eyes. The upward movement of the eye is present in the majority of the population, and is a defensive mechanism.
  • Normal- upward and outward
  • Inverse- upward and inward
  • Reverse- downward
  • Perverse- lateral

Abnormal bell's phenomenon may be seen in patients with Bell’s palsy, following conjunctival scarring, residual ptosis, ptosis with myopathy and congenital complicated ptosis

Berlin (Rudolf August Berlin : German ophthalmologist, 1833- 1897)

• Berlin's edema- grey-white discolouration of the retina due to disruption of outer segment photoreceptor layer following blunt trauma. This is caused due to contrecoup injury. Shock waves caused due to impact traverses the fluid- filled eye and then strike retina.
• Berlin's nodule- Granulomatous iris nodules seen in the angle in Sarcoidosis

Bjerrum (Jannik Peterson Bjerrum: Danish ophthalmologist, 1851- 1920)

• Bjerrum scotoma- a visual field defect characteristic of glaucoma. It is a nerve fiber bundle defect extending from the blind spot, sweeping around the macular region and ending in a straight line on the nasal side corresponding to the temporal raphe in the retina.
• Bjerrum screen-It is a flat, usually black surface, used to measure the central 30 degrees of the visual field. The Bjerrum screen is made of black matte material and stitched with radial lines at 15 degree intervals and circles at 5 degree intervals.

Brown (Harold Whaley Brown : American ophthalmologist, 1898- 1978)

• Brown syndrome- Brown syndrome is a vertical strabismus syndrome characterized by limited elevation of the eye in an adducted position, most often secondary to mechanical restriction of the superior oblique tendon/trochlea complex.
• Pseudo-brown syndrome- also known as acquired Brown’s syndrome is usually caused by an inflammation around the superior oblique tendon and trochlea. Causes of acquired Brown’s syndrome or pseudo-Brown’s syndrome include floor fracture, peri-trochlear scarring or superior oblique tendon sheath syndrome, trochlear inflammation (rheumatoid arthritis), glaucoma implant under superior oblique tendon in the superior nasal quadrant, or fat adherence syndrome.
• Brown classification- Brown classified Duane's syndrome according to the characteristics of the limitation of movement-
• • Type A: with limited abduction and less-marked limitation of adduction
  • Type B: showing limited abduction but normal adduction
  • Type C: the limitation of adduction exceeds the limitation of abduction. There is an exotropic deviation and a head turn to compensate the loss of adduction

C

Chandler (Paul A. Chandler 1896 - 1987; James Ryan Chandler: Otolaryngologist 1923-2004)

• Chandler's syndrome- Chandler syndrome is the most common type of Iridocorneal Endothelial Syndrome(ICE). It usually presents with a greater degree of corneal pathology with associated corneal edema. The corneal endothelium gives a ‘beaten bronze’ or ‘hammered silver’ appearance.. In these patients, the normal endothelial cells is seen to be replaced by a more epithelial-like cell with migratory characteristics.
• Chandler’s procedure- Used for malignant glaucoma/ aqueous misdirection syndrome. Chandler described the technique of vitreous aspiration through an 18 gauge needle via an incision 4 mm behind the limbus in conjunction with anterior chamber reformation with saline/ air.
• Chandler’s classification- Chandler classification system for orbital infections: I, inflammatory edema (preseptal cellulitis); II, Orbital cellulitis; III, Sub Periosteal abscess; IV, Orbital abscess, and V, cavernous sinus thrombosis.

Coats (George Coats: Scottish ophthalmologist,1876-1915)

• Coats disease- It is a telangiectatic neovascular disease of the retina characterised by massive exudation of unknown etiology that frequently affects unilateral eyes of young males.
• Coats ring- It is a superficial ring of iron deposition that occurs after a metallic foreign body is removed. It appears as a tiny ring of white dots, most often inferiorly. It is thought to result from previous iron deposition by a corneal foreign body and occurs long after resolution of the corneal iron ring.

Cogan (David Glendenning Cogan : American ophthalmologist, 1908-1993)

• Cogan's dystrophy- Cogan’s microcystic epithelial dystrophy ( also known as Epithelial basement membrane dystrophy / Map-dot-fingerprint dystrophy/ Anterior basement membrane dystrophy) is a subtype of epithelial and subepithelial dystrophies. Gray patches, pseudocysts, and/or fine lines in the corneal epithelium are noted on examination. Four kinds of patterns are seen- fingerprint lines, maps, dots, bleb pattern(Bron).
• Cogan's syndrome- Cogan’s syndrome is a rare disorder of unknown origin, characterized by inflammatory eye disease most commonly interstitial keratitis and vestibulo-auditory symptoms like vertigo, tinnitus and deafness.
• Cogan’s rule - Cogan’s rule states that, in a patient complaining of homonymous hemianopia, if there is an asymmetric optokinetic, the lesion is more likely to involve deeper portion of parietal lobe.
• Cogan's twitch- Cogan’s lid twitch sign, characteristic of myasthenia gravis, consisting of brief overshoot twitch of lid retraction following sudden return of the eye to the primary position after a period of downgaze.
• Cogan reese syndrome- also known as Iris-nevus syndrome is one of the clinical variants of ICE syndrome, characterized by nodular pigmented lesion of the iris. Secondary glaucoma is the main sight threatening complication.

D

Donders (Franciscus Donders : Dutch ophthalmologist, 1818–1889)

• Donder’s reduced eye- Donders treated the eye as a single curved surface with the following cardinal data : Principal point (P), Nodal point (N), Anterior focal length (f1), Posterior focal length (f2). Total power is 60D.
• Donder’s law of ocular motility: According to donder’s law, the eye’s gaze direction determines its orientation uniquely, and moreover, the orientation does not depend on the history of eye motion which has lead to the given gaze direction.
• Donder’s table- Donder’s table for age referenced amplitude for accommodation:

• Donder’s ring - Donder’s ring is an obsolete term for iridescent rings or halos observed in a cloudy cornea due to acute glaucoma.

E

Elschnig (Anton Elschnig : Austrian ophthalmologist, 1863-1939)

• Elschnig pearls - Accumulation of clusters of proliferated epithelial cells particularly seen in post operative cataract patients. They have the appearance of bunch of grapes or soap bubbles. May migrate to posterior capsule, continue to accumulate and cause significantly decreased vision.
• Elschnig's spots- Elschnig spots are yellow demarcated lesions in the perimacular region that leak fluorescein after occlusion of the choriocapillaris. When the Elschnig spot heals, a pigment spot is left surrounded by a depigmented pale halo. They are signs of hypertensive choroidopathy.
• Elschnig’s scleral ring- is a normal anatomic variation whereby a thin white ring, also known as the scleral lip, is seen immediately adjacent to the optic disc margin. It is caused by an anterior extension of the sclera between the choroid and optic nerve. The RPE and choroid tissue terminates just short of the optic disc, thus allowing visualization of scleral tissue through the transparent nerve fiber bundles.
• Border tissue of elschnig- The border tissue of Elschnig refers to densely compacted connective tissue that rises up from the sclera to join the Bruch’s membrane and thereby enclose the choroid.

F

Fuchs (Ernst Fuchs : Austrian ophthalmologist, 1851-1930)

• Fuchs spot- Fuchs spot (also referred to as Forster-Fuchs spots) is an area of retinal pigment epithelium hyperplasia suspected to be the response of the retinal pigment epithelium to previous regressed choroidal neovascular membrane.
• Dalen fuchs nodules- are clusters of epithelioid cells containing pigment lying between the RPE and Bruch's membrane. They are seen in case of sympathetic ophthalmitis.
• Fuchs heterochromic iridocyclitis- Fuchs’ uveitis syndrome (FUS) is a unilateral chronic mild anterior uveitis characterised by heterochromia, cataract and associated secondary glaucoma. Low grade uveitis with stellate KPs, iris atrophy, iris nodules, crystals and rubeosis are common features.
• Fuchs endothelial dystrophy- Fuchs dystrophy is characterized as a late onset (age >50), slowly progressive disease with decreased visual acuity in the morning that initially improves throughout the day, diffuse corneal opacification, and stromal edema. The disease is generally bilateral, but it may be asymmetric with one eye having more severe disease than the other. The endothelial cells show features of polymegathism and pleomorphism.
• Fuchs phenomenon- It is the paradoxical lid retraction associated with eye movements occurring in case of 3rd nerve regeneration. When the eye is adducted, the lid elevates. Classically seen in exophthalmic goiter, can also be due to trauma or tumor at the base of the skull, anterior poliomyelitis or vascular lesions of the brain stem
• Fuchs coloboma- also known as tilted disc syndrome, the superior pole of the optic disc may appear elevated with posterior displacement of the inferior nasal disc, or the disc can be horizontally tilted, resulting in an oval-appearing optic disc with an obliquely oriented long axis. This can be often accompanied by an inferior scleral crescent or situs inversus (a nasal detour of the temporal retinal vessels as they emerge from the disc before turning back temporally), and posterior ectasia of the inferior nasal fundus.
• Fuchs' superficial marginal keratitis- an uncommon condition characterized by intermittent, recurrent episodes of ocular irritation accompanied by marginal infiltrates and followed by progressive marginal superficial stromal thinning. Usually has an indolent course with spontaneous remission, and good visual acuity is preserved. In advanced cases, a pseudopterygium may develop in the area of thinning.

Fleischer (Bruno Fleischer : German ophthalmologist, 1874-1965)

• Kayser fleischer ring- also referred to as Fleischer-Kayser ring or Fleischer-Strumpell ring is a golden brown or greenish yellow ring seen at the corneoscleral limbus due to copper particles which infiltrate into Descemet's membrane through the endothelial cells from the aqueous humor. It is commonly seen in cases of Wilson's disease, cryptogenic cirrhosis, chronic active hepatitis, neonatal hepatitis, primary biliary cirrhosis, cholestatic cirrhosis and intraocular foreign body containing copper.
• Fleischer ring- Partial or complete iron deposition ring in deep epithelium encircling the base of the cone seen in eyes with keratoconus.It appears as a yellowish to dark-brown-colored ring best seen using cobalt blue light.

G

Goldmann (Hans Goldmann : Swiss ophthalmologist, 1899-1991)

• Goldmann Perimeter- The Goldmann perimeter is a manual kinetic perimeter which was used in the era prior to development of Humphreys field analysis. It presents targets on a bowl set 33 cm away from the cornea of the patient, with a background illumination of 31.5 apostilbs (asb).
• Goldmann Tonometer- Goldmann applanation tonometer measures the IOP by applanating 3.06mm of the cornea. It is based on the imbert-ficks law.
• Goldmann Goniolens- Goldmann Single Mirror: Single mirror inclined at 62º.

Goldmann three mirror has 3 mirrors. Mirror for gonioscopy is inclined at 59º and is tongue shaped. A second mirror views equator, is inclined at 67º and is trapezoid. The last mirror is for viewing parsplana, is inclined at 73º and is rectangular.

• Goldmann Dark adaptometer- Goldmann-Weekers adaptometer is used to assess dark adaptation time. The patient is first light-adapted to a bright background light. This light is then extinguished, and the patient, now in the dark, is presented with a series of dim light targets approximately 11° below fixation. The intensity of the test lights is controlled by neutral-density filters, and the threshold at which the test light is perceived is plotted against time.
• Goldmann favre disease- Goldmann-Favre syndrome (GFS) is a progressive retinal degeneration that develops due to a mutation in the NR2E3 gene, which has a role in the regulation of cone cell differentiation, and has an autosomal recessive inheritance pattern. It is typically characterized by hyperpigmented RPE clumps that form along the retinal vascular arcades, areas of chorioretinal atrophy, cystoid or schisis-like changes in the fovea, central or peripheral retinoschisis, vitreous degeneration, and cataract.

Grafe (Albrecht von Graefe : German ophthalmologist, 1828–1870)

• Von Grafe sign- Von Graefe's sign is the lagging of the upper eyelid on downward rotation of the eye, indicating exophthalmic goiter (Graves' Disease).
• Pseudo Graefe's sign (pseudo lid lag)- characterized by elevation or retraction of the upper eyelid when the eye is looking downwards and inwards. This synkinesis is caused by an aberrant regeneration of newly formed axons of the third nerve that subsequently reach muscles not originally connected with them. Commonly occurs in paralysis of the third nerve following various intracranial diseases: aneurysms, traumas and tumors.
• Von Grafe knife- One of the instruments used in cataract surgery in old times. von Grafe knife has the narrow tapered blade designed to keep the anterior chamber from collapsing as a double puncture was pre-formed
• Von Grafe test for phorias- The von Graefe test has been popular for measuring phorias for many years and here the dissociation is achieved with the help of vertical prisms.In the test, a dissociating prism (6Δ base‐up) was placed in front of the right eye and a measuring prism (12Δ base‐in) in front of the left eye. Subjects were instructed to fixate at the N8 line in the near vision chart held by them and were told to keep the letters clear all the time. The examiner then asked the subjects to look at the lower target and requested them to inform the examiner when the upper target appeared just above the lower target. The magnitude of the horizontal prism was changed in one‐dioptre steps until the subjects reported that both images appeared one below the other.
• Von Grafe strabismus hook- A straight shaft, right angled flattened hook tip instrument used in squint surgeries for hooking the extraocular muscles.

Gullstrand (Allvar Gullstrand : Swedish Ophthalmologist 1862-1930)

• Gullstrand schematic eye- Gullstrand made a six surface eye model : six spherical refractive surfaces, two for the cornea and four for the crystalline lens. Lens is seen as a central double convex core surrounded by a cortex that has a lower index of refraction.The cardinal points of the schematic eye include : 2 principal foci F1and F2, two principal points P1and P2, two nodal points N1and N2. The total diopteric power calculated was 58.64D
• Gullstrand’s equation- Gullstrand equation can be used to calculate the effective focal length of a thick lens or two separated lens.

P= P1 + P2 - P1P2 d/n Where, P is the equivalent power(in Diopters) , P1 is the power of 1st lens, P2 is the power of 2nd lens, d is the distance between the two lenses (cm), n is the refractive index of the media.

H

Haab (Otto Haab : Swiss ophthalmologist, 1850-1931)

• Haab’s striae- Haab striae are curvilinear breaks in Descemet's membrane, resulting acutely from stretching of the cornea in primary congenital glaucoma. They are typically oriented horizontally or concentric to the limbus.
• Haab’s magnet- A powerful magnet used by vitreo-retina surgeons for removing intraocular metallic foriegn body particles.
• Haab’s reflex- Attention reflex with contraction of pupils without alteration of the eye’s position (accommodation or convergence) when attention is on a bright object in the periphery of vision. May indicate a cortical lesion.
• Biber-Haab-Dimmer degeneration- Localised ocular amyloidosis with onset at 20-30 years of age, affecting both sexes. It is manifested by progressive corneal opacity with distinct borders and a network of lattice-like branching filaments. Round spots may be scattered throughout the cornea, but the intervening spaces are clear, and there may be extracellular deposits of amyloid material

Henle (Friedrich Gustav Jacob Henle : German anatomist and pathologist, 1809-1885)

• Hassall henle bodies- small transparent growths on the posterior surface of descemet's membrane at the periphery of the cornea. These bodies contain collagenous matter in which numerous cracks and fissures are filled with extrusions of the corneal endothelium. The condition is usually associated with the aging process.
• Henle's layer- The outer fibre layer of Henle is the foveal portion of the outer plexiform layer of the retina. This layer is composed of the elongated inner processes of the foveal cones and rods which radiate with a peculiar slant away from the foveal pit. These inner processes, thus, represent short neurites connecting the visual cells with their bipolar cells.
• Crypts of henle- gland like epithelial invaginations. They are found along the full length of the upper one third of the conjunctival surface of the upper tarsus and similarly along the lower one third of the lower tarsus. They have a role in mucin secretion.

Hutchinson (Jonathan Hutchinson : English ophthalmologist, 1828 -1913)

• Hutchinson's pupil- A clinical sign in which the pupil on the side of an intracranial mass lesion is dilated and unreactive to light, due to compression of the oculomotor nerve on that side. It is due to concussion injury to brain and is often associated with subdural hemorrhage and unconsciousness.
• Hutchinson's triad- characterised by the presence of interstitial keratitis, eighth nerve deafness and Hutchinson’s teeth in a case of congenital syphilis.
• Hutchinson’s sign- is defined as skin lesions at the tip, side, or root of the nose. This is a strong predictor of ocular inflammation and corneal denervation in herpes zoster ophthalmicus, especially if both branches of the nasociliary nerve are involved.
• Hutchinson's patch - also known as salmon patch of Hutchinson. It is an ill defined dull orangish-pink area on the cornea, most often found at the periphery of the cornea. The sign is an indication of interstitial (or parenchymatous) keratitis, causing corneal neovascularisation.
• Hutchinson- Tay choroiditis- It is an autosomal dominant hyaline dystrophy also known as familial dominant drusen. In dominant drusen, the drusen cover the posterior pole, extending nasally to the disc, often in a radial, mosaic or honeycomb pattern. The lesions closer to the fovea tend to be larger and coalesce with age. The appearance is often symmetric between the two eyes.

Horners (Johann Friedrich Horner : Swiss ophthalmologist, 1831- 1886)

• Horner's Muscle - Horner's muscle (the palpebral part of the orbicularis oculi muscle) has a fan-shaped origin in the lacrimal bone. Its muscle fibers are oriented from 160 to 210 degrees relative to the ear-eye plane and converge towards the medial palpebral commissure.It has following roles: (1) it closes the medial canthus of the eye and closes the lacrimal punctum; (2) it pulls the tarsus medially; (3) it tautens the palpebral margins and presses against the eyeball; and (4) it squeezes the lacrimal canaliculus with a decreasing gradient of pressure from the lacrimal papilla to the lacrimal sac.
• Horner trantas spots - These are gelatinous thickened accumulation of tissue around limbus and presence of discrete whitish raised dots made up of degenerated epithelial cells and eosinophils along the limbus.They are seen characteristically in Vernal keratoconjunctivitis.
• Horner's syndrome- Horner syndrome is a condition classically presenting with partial ptosis (drooping or falling of upper eyelid), miosis (constricted pupil) and facial anhidrosis (loss of sweating) due to a disruption in the sympathetic nerve supply. It can be of 3 types:
  • Central (first order neuron) Horner’s: lesions of the hypothalamus, brainstem and spinal cord such as stroke, demyelination or neoplasms
  • Preganglionic (second order neuron) Horner’s: cervical rib, Pancoast's tumor, thyroid malignancies
  • Third order neuron or postganglionic lesion: lesions of the superior cervical ganglion, ICA (dissection, thrombosis, invasion by tumors), lesions of the sellar and parasellar regions

K

Kelmann (Charles David Kelman : American ophthalmologist, 1930 – 2004)

• Kelmann mcpherson forceps- curved non toothed lens holding forceps with smooth jaws for non traumatic holding of IOLs. It can also be used for tying sutures.
• Kelmann tip- it is a bent phacoemulsification tip used in torsional phacoemulsification.

Kestenbaum (Alfred Kestenbaum, 1890-1961)

• Kestenbaum Index- is the number of capillaries counted on the optic disc, which normally is around 10. Less than 6 capillaries indicates optic atrophy; more than 1 suggests disc hyperaemia.
• Kestenbaum Sign- Reduction in the number of capillaries on optic disc surface in case of optic atrophy
• Kestenbaum Procedure- It is a surgery done for nystagmus to improve head posture and move the eyes toward the null position. In this procedure rule of 13 is followed wherein each eye the amount of surgery performed is 13 mm including the medial and the lateral recti. In each eye, the yoke muscles are recessed and resected according to m the desired shift in position. For example, for a left face turn the left lateral rectus is recessed 7 mm and left medial rectus is resected 6mm (making a total of 13 mm) and the right medial rectus is recessed 5 mm and lateral rectus is resected 8 mm.
• Kestenbaum Pupil number- Kestenbaum's number (K) is the difference in the pupil size attained in each eye under direct illumination while the other eye is occluded. In this test, the pupillary reaction to prolonged light exposure is assessed. When any patient has unilateral optic nerve dysfunction or asymmetric involvement of optic neuropathy, with the patient in the light, covering the eyes alternatively reveals that pupil of the normal eye constricts when it is uncovered, and the abnormal eye is covered. In contrast, the pupil of the eye with optic neuropathy dilates when it is uncovered, and the pupil of the normal eye is covered. Here the size of pupils is measured.
• Kestenbaum Rule- Kestenbaum proposed that the reading addition required to read 1 M print is equal to the minimum angle of resolution (eg. if VA = 20/200, MAR = 200/20, and required add = +10D).
• Kestenbaum limbus test of motility- Kestenbaum measured the limitation of eye movement in millimetres with a transparent ruler held in front of the cornea to note the limbus position in primary position compared with the gaze (new) position. This test was intended for the quick investigation of patients with muscle paresis. A mean value of 9–10 mm in abduction, adduction and depression and a mean value of 7 mm in elevation is considered normal.

Kimura (Kimura T : Japanese ophthalmologist, 1909-1982)

• Kimura spatula- commonly used instrument in corneal scrapings and conjunctival scrapings. The tip of the spatula is designed to typically run along the inferior palpebral conjunctiva without causing excess tissue damage or irritation.
• Kimura's disease orbit- Kimura’s disease is a chronic, benign inflammatory disease of the subcutaneous tissue, which most often presents with painless, subcutaneous nodules of the head and neck in association with eosinophilia and elevated serum IgE. Patients who present with orbital involvement usually report painless swelling, eye redness, tearing, and occasionally headache or diplopia.

Koeppes (Leonhard Koeppe: German Ophthalmologist 1884-1969)

• Koeppe's Nodules- Koeppe nodules are inflammatory cell precipitates which lie at the pupillary margin and could be found in non-granulomatous as well as granulomatous uveitis. They resolve with resolution of inflammation.
• Koeppes goniolens- The Koeppe lens is a 50-diopter lens, is placed on the eye of a recumbent patient using saline to bridge the gap between lens and cornea. The examiner views the angle through a hand-held binocular microscope, which is counterbalanced to permit ease of handling. Illumination is provided by a light source that is held in the other hand. The Koeppe lens magnifies ×1.5 and in combination with the ×16 magnification of the oculars, yields a total magnification of ×24. They are available in several sizes.

Krachmer (Jay H Krachmer: American Ophthalmologist)

• Krachmer grading system : The Krachmer grading scale is used to subjectively evaluate the progression in Fuchs endothelial corneal dystrophy(FECD).

Grade 0- negative

Grade 1- 0 to 12 central guttae

Grade 2- >12 central nonconfluent guttae

Grade 3- 1 to 2 mm of confluent central guttae

Grade 4- 2 to 5 mm of confluent central guttae

Grade 5- >5mm of confluent central guttae or G4 with stromal/ epithelial edema.

• Krachmer spots : Krachmer spots are seen on corneal epithelial rejection. These are subepithelial opacities, similar in appearance to adenoviral keratitis, which are present in bowman's layer.

L

Lebers (Theodor Karl Gustav von Leber : German ophthalmologist, 1840 – 1917)

• Leber's congenital amaurosis- It is an autosomal recessive disease characterised by abnormal function and degeneration of the retina. Parents may notice their child does not seem to fix his or her gaze on objects or follow moving objects. This visual impairment is often accompanied by eye rubbing (oculodigital sign), as the rubbing stimulates the photoreceptor cells to see light. LCA patients classically have a “flat” ERG, which suggests virtually no retinal function.
• Leber's hereditary optic neuropathy- Leber Hereditary Optic Neuropathy (LHON) is the most common inherited mitochondrial disorder and typically affects young males in the second to fourth decade of life. It typically begins as a unilateral progressive optic neuropathy with sequential involvement of the fellow eye months to years later. Dilated fundus examination may be normal, or reveal hyperemic, "pseudo-edematous" optic nerves with peripapillary telangiectasias. Tortuosity of retinal arterioles may also be present.
• Leber's miliary aneurysm- Leber's disease is a form of primary retinal telangiectasia characterized by the presence of abnormalities in the retinal vasculature particularly multiple miliary aneurysms associated with intraretinal lipid exudates. It is an idiopathic, unilateral condition with male predilection. The disease has a very slow progression and can be complicated by vascular dilatations, neovascularizations, thromboses, retro vitreal hemorrhages, and macular changes.

Lisch (Karl Lisch : Austrian Ophthalmologist 1907-1999)

• Lisch nodules- Lisch nodules are melanocytic hamartomas of the iris, often associated with neurofibromatosis (NF) I. They are usually elevated and tan in appearance.
• Lisch syndrome- Syndrome of perlucide (translucent) iris with hereditary nystagmus and with/without fundus flavimaculatus. Inheritance is autosomal dominant.
• Lisch dystrophy- It is a very rare form of superficial corneal dystrophy characterized by feather-shaped opacities and microcysts in the corneal epithelium arranged in a band-shaped and sometimes whorled pattern, occasionally with impaired vision.

M

Marcus Gunn (Robert Marcus Gunn: Swedish Ophthalmologist 1850-1909)

• Marcus Gunn pupil- the term given to an abnormal pupil showing aberrant pupillary response. Also known as a relative afferent pupillary defect (RAPD).After exposure to bright light, a normal pupil constricts.A Marcus Gunn pupil, on the other hand, has a relative weakness of the afferent limb of the pupillary light reflex compared to the other eye because of which when light is rapidly transferred from the normal eye to the abnormal eye it dilates instead of constricting.
• Marcus Gunn jaw winking phenomenon- Marcus-Gunn (M-G) jaw-winking phenomenon is the most common congenital synkinetic movement. When the mouth is opened or the jaw is moved laterally, the ptotic eyelid elevates. This results from a congenital, aberrant connection between the trigeminal nerve controlling mastication and the oculomotor nerve supplying the levator. If the jaw is deviated to the affected side, the ptosis increases, but if it deviates towards the opposite side, a maximal retraction occurs.
• Inverse Marcus Gunn jaw winking phenomenon- In the inverse M-G phenomenon, the ipsilateral eyelid closes when the external pterygoid muscle moves the jaw to the opposite side. When eyes are in primary position and mouth closed, there is a mild degree of ptosis in the affected eye.
• Gunns dots- tiny white dots sometimes visible overlying the large vessels near the optic nerve or the nerve fiber layers. Their presence depends on lighting conditions, and they have no pathologic significance. They are visible reflections of the internal limiting membrane, created by the footplate of the muller cells. The tiny white specks in these photos are best visualized at the 12:00 and 6:00 positions approximately 1 disc diameter from the optic nerve head.
• Gunns sign- Tapering of the retinal vein on either side of the arterio-venous crossing. Seen in case of hypertensive retinopathy.

P

Parinaud (Henri Parinaud : French ophthalmologist, 1844- 1905)

• Parinaud Syndrome- include the triad of upgaze paralysis, convergence retraction nystagmus, and pupillary light-near dissociation. It is caused due to compression of the rostral midbrain and pretectum at the level of the superior colliculus with some of the main nuclei being the interstitial nuclei of Cajal and the rostral interstitial nucleus of the Medial Longitudinal Fasciculus (riMLF).
  • Limited conjugated upgaze
  • convergence- retraction nystagmus which is characterized by an irregular, jerky nystagmus, associated with convergence and retraction of both eyes, especially on attempted upgaze.
  • poor pupillary constriction to light but preserved constriction with convergence.
• Reverse Parinaud syndrome- In this condition, there is downgaze palsy instead of upgaze palsy, and the patient presents with the combination of downgaze palsy with convergence weakness and pupillary light-near dissociation. This is an extremely rare condition.
• Parinaud Oculoglandular syndrome- It is a conjunctival disease characterized by a unilateral granulomatous follicular conjunctivitis associated with ipsilateral regional ( preauricular and submandibular) lymphadenopathy. There are many vectors that transmit and organisms that cause oculoglandular syndrome, of which, Cat Scratch Disease is the most common cause.

Park (Marshall Miller Parks : American ophthalmologist, 1918 – 2005)

• Park 3 step test- The three-step test, also known as the Parks-Bielschowsky three-step test or the Parks-Helveston three-step test, is a diagnostic test used to identify which muscle is paretic in the case of an acquired hypertropia.
  • The first step in the three-step test is to determine which eye is hypertropic in primary position.
  • The second step is to determine whether the hypertropia increases on the right or left gaze.
  • The third step is determination if the hypertropia increases upon left head tilt or right head tilt. For this test, the ophthalmologist or orthoptist uses prisms to quantify the hypertropia in primary position, side gazes, and head tilts. Alternatively, it can be helpful to quantify smaller deviations using prisms and a Maddox rod or red filter.
• Parks monofixation syndrome- Monofixation syndrome, defined by Marshall M. Parks in 1969, is a form of subnormal binocular vision without bifixation characterized by small-angle strabismus, unilateral absolute facultative central suppression scotoma of less than 3º, and peripheral fusion. It is caused by conditions that cause a suppression scotoma in the central retina but allow for peripheral fusion.
• Park nystagmus surgery- Parks 5-6-7-8 ‘rule’ (medial recession 5 mm, medial resection 6 mm, lateral recession 7 mm, and lateral resection 8 mm) proposes the amount of surgery for a small face turn in case of nystagmus.

Posner (Adolf Posner : Polish Ophthalmologist 1906-2002)

• Posner gonio lens- It is a hand held gonio lens which allows all 4 quadrants of the chamber angle to be visualized without rotation of the lens during examination. It has a smaller area of contact than the Goldmann-type lens and about the same radius of curvature as the cornea, thus is optically coupled by the patient’s tears. It is used for dynamic gonioscopy and distinguishing iridocorneal apposition from synechial closure.
• Posner-schlosmann syndrome- also known as glaucomatocyclitic crisis, is a disease characterised by acute, unilateral, recurrent attacks of elevated intraocular pressure accompanied by mild anterior chamber inflammation usually occurring in adults between the age of 20-50 years.

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Shaffer (Robert Nesbit SHAFFER 1912 - 2007)

• Shaffer Grading- describes the degree to which the anterior chamber angle is open. The Shaffer system approximates the angle at which the iris inserts relative to the trabecular meshwork. If the angle between the iris and the meshwork is 20° to 45°, the angle is felt to be at no risk of closure. Angles from 0° to 20° are considered capable of closure
• Shaffer sign- Also called “tobacco dust,” Shafer’s sign refers to the presence of a collection of brown pigmented cells in the anterior vitreous following a retinal break or detachment and rarely posterior vitreous detachment.
• Richardson shaffer lens- It is one of the direct goniolens used for infants and is basically a small Koeppe lens.

Siedels (Erich Seidel : German ophthalmologist, 1882-1946)

• Siedels test- Method of detecting wound leak by observing aqueous dilute concentrated fluorescein placed over the suspected leakage site. Usually done for traumatic or postoperative suspected leakage from the anterior chamber.
• Siedels scotoma- Seidel’s Sign (also called Seidel’s Scotoma) is a sickle-shaped scotoma that is a superior or inferior extension of the blind spot. It occurs in some patients with glaucoma.

Scheies (Harold Glendon Scheie: American ophthalmologist, 1909-1990)

• Scheie's Grading- Gonioscopic grading system
  • Wide-Open, all structures visible
  • I (Slightly Narrowed)- Ciliary body visible, but recess obscured by the last roll of the iris
  • II (Apex not visible)- Ciliary body not visible
  • III (Posterior half of trabecular meshwork not visible)- Ciliary body, scleral spur, and posterior half of the trabecular meshwork not visible
  • IV (None of the angle structures visible)- Ciliary body, scleral spur, and trabecular meshwork not visible.
• Scheie's syndrome- Glycogen storage disease leading to a deficiency in the enzyme α-L-iduronidase, which is responsible for the degradation of glycosaminoglycans within the body. Ophthalmic findings may be proptosis, progressive corneal opacification, corneal edema, open angle glaucoma, pupillary- block glaucoma, cataracts, retinitis pigmentosa, and epiretinal membranes.
• Scheie's visual field grading system- The SCHEIE grading system is a reproducible tool that combines qualitative and quantitative measurements to grade glaucomatous visual field defects. It aims to standardize clinical staging and to make specific visual field defects more easily identifiable.
• Scheie’s classification -
  • For Hypertensive Retinopathy
    • Stage 0: No visible abnormalities
    • Stage 1: Diffuse arteriolar narrowing
    • Stage 2: Stage 1 + focal arteriolar constriction
    • Stage 3: Stage 2 + retinal hemorrhage
    • Stage 4: Stage 3 + hard exudates + retinal edema+ optic disc swelling
  • For Arteriosclerosis
    • Stage 0: Normal
    • Stage 1: Broadening of arteriolar light reflex
    • Stage 2: Stage 1 + AV crossing changes
    • Stage 3: Copper wiring of arterioles
    • Stage 4: Silver wiring of arterioles
• Scheies stripe- pigment deposition along with the insertion of the zonular fibers to the lens in patients with pigment dispersion syndrome.
• Scheies procedure- The Scheie procedure for uncontrolled glaucoma prepares a scleral fistula under tenon's capsule and conjunctiva using electrocautery to mark the incision and to induce the retraction of the posterior lip of the fistula

Schwalbe (Gustav Albert Schwalbe : German anatomist and anthropologist, 1844-1916)

• Schwalbe Line- Schwalbe's line is the anatomical line found on the interior surface of the cornea, and delineates the outer limit of the corneal endothelium layer. Specifically, it represents the termination of Descemet's membrane.
• Schwalbe Ring- The Schwalbe ring represents the junction of the trabecular meshwork with the termination of Descemet’s membrane, and is visible in 8%–30% of normal eyes as an irregular, opaque ridge 0.5–2.0 mm central to the limbus. The term posterior embryotoxon is used when the Schwalbe ring is visible by external examination.
• Schwalbe Spaces- The subarachnoid or subdural spaces between the internal and external sheaths of the optic nerve are referred to as schwalbe's spaces; also called the intervaginal spaces of optic nerve.
• Schwalbe’s folds - The posterior surface of the iris has two types of radial folds: (1) contraction folds of Schwalbe, which are small sulci that run for a distance of 1 mm, bending over the pupillary aperture and forming the crenations on its anterior surface and (2) structural folds of Schwalbe, which begin about 1.5 mm from the pupillary border and extend between the ciliary processes.

Snellen (Herman Snellen: Dutch ophthalmologist, 1834 – 1908)

• Snellen visual acuity chart- most commonly used test for visual acuity
• Riesman's sign or Snellen-Riesman's sign - is a clinical sign characterized by bruit heard over the closed eye with a stethoscope in Graves' ophthalmopathy in thyrotoxicosis. The bruit is heard during systole.
• Snellen’s Operation- surgery is done for trichiasis with slight entropion or only involving part of the eyelid or entropion with a very thickened tarsal plate. A wedge is excised from the front of the tarsal plate so that the margin of the tarsal plate can rotate outwards. An ellipse of skin and muscle from the front of the eyelid is usually excised also, and a grey-line split performed as well. This helps the eyelashes to evert further.

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Vogt (Alfred Vogt: Swiss ophthalmologist, 1879-1943)

• White Limble girdle of Vogt- This girdle is a degenerative change of the anterior limiting membrane, with chalk-like opacities and small clear areas like the holes in Swiss cheese. Type I is a narrow, concentric, whitish superficial band running along the limbus in the palpebral fissure. A lucid interval appears between the limbus and the girdle. Type II consists of small white, fleck like, and needlelike deposits that are often seen at the nasal and temporal limbus in older patients. No clear interval separates this girdle from the limbus. The histopathologic picture represents epithelial elastotic degeneration of collagen, sometimes with particles of calcium.
• Vogt striae- Vogt's striae are vertical fine, whitish lines in the deep/posterior stroma and Descemet's membrane commonly found in patients with keratoconus. There is a positive correlation between the orientation of the lines with the steepest axis of the cornea and the mechanism is thought to be related to mechanical stress forces on collagen lamellae radiating from the cone apex. The striae can temporarily disappear with external pressure to the globe.
• Vogt crocodile shagreen- characterized by a grayish, polygonal pattern of opacities with intervening clear zones across the central cornea that resembles crocodile skin. It is a benign, degenerative disorder and is commonly found in the elderly population.
• Vogt Koyanagi Harada syndrome- is defined as a bilateral granulomatous panuveitis with or without extraocular manifestations affecting young adults.
• White lines of Vogt- Sheathed or sclerosed vessels seen in Lattice degeneration.

Lattice degeneration of the retina is a fairly common degenerative disease of the peripheral retina characterized by the presence of lattice lines created by fibrosed blood vessels. Crisscrossing fine white lines that account for the name lattice degeneration is present in roughly only 10% of lesions and most likely represent hyalinized blood vessels.

• Palisades of Vogt - The palisades of Vogt are distinctive normal features of the human corneoscleral limbus. They are more discrete in younger and in more heavily pigmented individuals, and that they appear more regular and prominent at the lower limbus than at the upper limbus. The anatomy of the palisades appears to be unique for a given individual thus the palisades of Vogt appear comparable to fingerprints, and the term "conjunctivoglyphics" ("conjunctival carvings") or "limboglyphics" is suggested.
• Vogt Triad of Glaucoma - Glaucomfleckens, iris atrophy (stromal), pigment on the corneal endothelium.
• Vogt triad of tuberous sclerosis- Facial nevus (adenoma sebaceum), seizures, mental insufficiency.

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Weiss

• Weiss reflex- Weiss reflex is an annular reflex concentric with the border of the disc and is mobile. It is formed by the elevation of the ILM where the nerve fiber layer is thickened; present at the nasal border of the disc.
• Weiss ring- A Weiss ring is a large, ring-shaped floater that is created by a posterior vitreous detachment (PVD) from around optic nerve head
• Weis surgery- is done for senile entropion. Full-thickness horizontal lid split and everting sutures. An incision is placed 3mm below the lid margin extending along the whole length of the eyelid. It involves the skin, orbicularis, and the tarsal plate. Mattress sutures are used for correcting the entropion by transpositioning the tarsus.

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Zinn (Johann Gottfried Zinn : German anatomist, ophthalmologist, and botanist, 1727-1759)

• Common Tendinous Ring of Zinn- The annulus of Zinn is a common tendinous ring surrounding the optic nerve at its entrance at the apex of the orbit. It signifies the common origin of the four rectus muscles.
• Zinn’s Zonules- The zonule of Zinn is a ring of fibrous strands connecting the ciliary body with the crystalline lens of the eye. The zonule is split into two layers: a thin layer that lines the hyaloid fossa and a thicker layer which is a collection of zonular fibers.
• Zinn’s Central Artery- The central retinal artery (Zinn’s artery) is a branch of the ophthalmic artery
• Circle of Zinn Haller- The arteries surrounding the optic nerve are sometimes called the “circle of Zinn-Haller”.