Practical Examination DNB Ophthalmology

The following write-up contains some of the frequently asked topics during the DNB practical examinations. Do keep in mind that this is just a sample, the scope of Ophthalmology is vast and it’s the 3 years effort put in during the course of residency that makes you comfortable to face the examination. It is important to have a thorough knowledge of the frequently asked questions, rather than knowing rare, obscure facts. In the end, it’s all back to basics! Any examiner starts questioning with a basic level of questions that he deems are essential knowledge for the candidate to pass or be qualified as an ophthalmologist, once the candidate clears that level only then does the examiner pose level 2 or level 3, the relatively tough/ rare/ newer questions. This should make clear that in order to clear the examination, level 1 questions MUST and should be answered! And that is what the following literature will focus on mostly.

Exam Pattern:

Most centers usually have:

2 Anterior Segment cases + 2 Posterior Segment Case + 1 Refraction Case =160 marks

Table viva = 140 marks

However, you may even have 2 anterior segments,1 posterior segment, 1 Squint or Oculoplasty case.

For the case presentation, it is important to make it a habit to practice from the beginning and formative years. Every patient you see, make it a point to present the case, even the “simple ones” like refractive errors or cataracts. There should be a flow chart in your mind each time you approach a case. This practice will help not only with improving your fluency and confidence but will also help you with a systematic approach for any case. Specific cases have a very specific proforma of presentation. These must be followed. e.g. ptosis or proptosis, socket exam, squint exam, etc.

Drugs

This forms a part of the table viva. You may be handed over a specific drug or may be asked to choose one from the available drugs. In either case, you must start by mentioning the drug name, it’s concentration, use and mechanism of action. Following is a list of frequently asked groups of drugs and specific drugs for which one must know: Classification and Pharmacological group of the drug , Mechanism of action, Duration of action, Dose, Indication, Contraindication, Uses, Side effects, Pharmacokinetics.

Antiglaucoma
Antifungal
Antibiotic
Antiviral
Anti-amoebic, Polyhexamethylene biguanide (PHMB) and Chlorhexidine for acanthamoeba keratitis
Mydriatics and cycloplegics
Lubricants
Preservatives
Steroids
Immunomodulatory drugs
NSAID
Ketorolac
Nepafenac
Natamycin
Mitomycin C (MMC), 5 fluorouracil (5-FU) (concentration and technique of application)
Implant Dexamethasone Sustained Release Device, antivirals and newer sustained drug delivery devices
Viscoelastic (triple shell technique)
Silicon oil
Perfluorocarbon Liquid, C3F8
Betadine (concentration of topical solution, scrub solution)
Lignocaine and other anesthetics and anesthesia techniques
Anti VEGF (Bevacizumab, Ranibizumab)
VEGF trap (Aflibercept/Eylea)

Optics:

This perhaps is one of the most interesting and conceptual topics in Ophthalmology. It really is easy to grasp, provided one refers to good textbooks and references for the same. A good idea for beginners would be to cover optics in the first year itself because this is the time when you have enough time on hand to go through standard textbooks rather than cram in the end. For the DNB practical exam following are the FAQs in optics:

Retinoscopy:

Principle
Working Distance
Adjustment For Various Drugs Like Atropine, Cyclopentolate, Tropicamide
Transposition, Spherical Equivalents

Refraction:

Trial frame, weight, which lens where to keep
Trial box how many lenses
Prism, plus lens, minus lens –how to identify
Concave lens, convex lens, cylinder
Convex lens diagnostic use, therapeutic use
Jackson cross-cylinder (JCC) uses, refine when to use, how to make a JCC with trial frame lenses
Maddox rod, Maddox wing uses
Colour vision
Worth four dot test
Progressive glass, centration
Myopia, hyperopia, and astigmatism: definition, types (including Simple myopic astigmatism, mixed, simple hyperopia, etc)
PL PR test (Perception of light and Projection of rays)
Aberrations (lower and higher-order)

Contact lenses:

Types, material, care, lens solution, the making of contact lenses, CL in special cases like keratoconus

Optics of various lenses:

20D, 78D, 90D (correction factors), Gonioscopy, and Gonio lens.

INSTRUMENTS

Direct Ophthalmoscope, Indirect Ophthalmoscope – Principle, Magnification, Function
Instruments used in Dacryocystectomy (DCT), Dacryocystorhinostomy (DCR), Cataract - Extracapsular cataract extraction(ECCE), Small incision cataract surgery (SICS), Phacoemulsification: know the basics of phacodynamics as well), PKP (Penetrating keratoplasty), squint, ptosis
Silicon oil, band, buckle, silicon oil, vitrectomy instruments, forceps, etc

IMAGING

Indication, principle, uses and special signs are seen on specific investigations

X-RAY
Computed tomography (CT)
Magnetic resonance imaging (MRI)
Ultrasonography( USG) : B-scan and A-scan
Optical coherence tomography (OCT)
Fundus Fluorescein Angiography (FFA)
Indocyanine angiography(ICG)
Heidelberg retinal tomography (HRT)
GDx Nerve Fiber Analyzer
Ultrasound biomicroscopy (UBM)
Anterior segment Optical coherence tomography (ASOCT)
Hess chart
Diplopia chart
Pentacam, Orbscan
Corneal Topography
PERIMETRY :

Definition and description of 30-2, 24-2, 10-2 and their specific utility
How to describe fields, reliability indices, global indices (normal values, etc)
Specific types of visual field defects ( like central scotoma, centrocecal scotoma, etc)
D/D of Tunnel Vision
Neurological Field Vs Glaucomatous Field

SURGERIES:

Sutures
Steps of SICS (small incision cataract surgery) and Phacoemulsification, complication
Size of Capsulorrhexis
Lens optic size
Tunnel size
Blumenthal technique
Hydro cannula gauze size
Squint: Max resection, recession, number of muscles that can be operated upon at a time
DCR Anatomy, Diagnostic tests (syringing, probing, etc)
Orbital implant
Fracture repair (techniques and implants used)

THESIS

The aim of the study
Type of study, statistical tests employed
Highlights and drawbacks of the study

Logbook

Please make sure you carry a neatly covered, well-bound logbook and not loose sheets enclosed in a folder. Your logbook is a reflection of your residency performance and it must not look unkempt.

Miscellaneous

List of Cases :

CORNEA

Ulcer –Bacterial, Fungal, Herpes
Healed Viral Keratitis
Non-Healing Ulcer
Penetrating keratoplasty – Optical Graft, Failed Graft, Therapeutic
Descemet stripping endothelial keratoplasty (DSEK ),
Deep Anterior Lamellar Keratoplasty (DALK)
Keratoconus
Peripheral ulcerative keratitis (PUK), Mooren’s Ulcer
Pseudophakic bullous keratopathy (PBK)
Corneal Opacity, Adherent Leucoma
Fuch’s Dystrophy
Keratoconus – Acute Hydrops, High Cylinder
Iridocorneal Endothelial Syndrome (ICE)Causes Of Iridocorneal Touch, Iridocorneal Dysgenesis
Ocular surface squamous neoplasia (OSSN)
Corneal Dystrophy
Vitamin A Deficiency

LENS

Cataract
Congenital cataract
Ectopia Lentis
Posterior capsular opacity (PCO)
Spherophakia

UVEA

Uveitis – anterior, intermediate, posterior
Endophthalmitis
Panuveitis
Vasculitis, Peripheral Vasculitis
Toxoplasma
Cytomegalovirus retinitis
Choroiditis, multifocal choroiditis

ORBIT

Proptosis
Thyroid ophthalmopathy,
Ptosis
Blowout fracture
Blunt trauma, penetrating injury
Empty socket and contracted socket
Read about orbital exenteration, Enucleation, Evisceration, structures removed, Indications, Contraindications
Cellulitis
Blepharophimosis, ptosis, and epicanthus inversus syndrome
Ankyloblepharophimosis

LID

Lid Tumour
Ectropion
Entropion
Ptosis

NEURO OPHTHALMOLOGY

3rd Nerve
4th Nerve
6th Nerve
7th Nerve
Pale Disc
Optic Atrophy
Non-arteritic anterior ischemic optic neuropathy (NAAION)
Anterior ischemic optic neuropathy (AION)
Disc Edema, Papilledema

GLAUCOMA

Primary open-angle glaucoma (POAG),
Advanced glaucoma
Primary angle-closure glaucoma
Neovascular glaucoma
Pseudoexfoliative glaucoma
Pigmentary Glaucoma
Patient of Trabeculectomy
Secondary glaucoma

RETINA

Retinal detachment
Vitreous hemorrhage
Retinitis pigmentosa
Diabetic macular edema
Nucleus Drop
Dystrophies

VASCULAR DISEASE

Central retinal vein occlusion
Branch retinal vein occlusion
Branch retinal artery occlusion
Central retinal artery occlusion
Diabetic retinopathy
Hypertensive retinopathy
Eale’s Disease
Sickle cell
Macular disorders
Age-Related Macular Degeneration – dry, wet
CNVM (Choroidal neovascular membrane)
Macular hole
Central serous retinopathy (CSR)
Epiretinal membrane
Cystoid macular edema
Best disease

LACRIMAL

Dacryocystitis
Lacrimal apparatus obstruction
S/P Dacryocystorhinostomy

SQUINT

Exodeviation
Esodeviation
Duane’s retraction syndrome
SO/ IO PALSY (Superior oblique/Inferior oblique palsy)
SO/ IO over action (Superior oblique/Inferior oblique overaction)
Double elevator palsy

MISCELLANEOUS

High Myopia
Myasthenia Gravis
Symblepharon, Burns

CHECKLIST BEFORE THE EXAM:

ADMIT CARD (Seems obvious, but you would be surprised at how many students forget the most obvious!)
Pens, Pencils, Color Pencil, Eraser, Sharpener
Scale: transparent two long, one small
Bangle or compass: to make a fundus diagram, preferable to carry a printed Amsler-Dubois chart as well for the posterior segment case.
Retinoscope, Gonioscope
78 D, 90 D, 20 D lens
Direct and Indirect ophthalmoscope
Paracaine, Moisol (to put on fluorescein strip for doing applanation tonometry), Tropicamide (for dilatation for fundus examination)
Torch
Thesis
Fluorescein strip, cotton

All the best !!