Articles

111–120 of 232 articles Page 12 of 24
All Cornea 36 Cataract 17 Glaucoma 13 Retina & Vitreous 72 Neurophthalmology 8 Oculoplasty 15 Uvea & Inflammatory Diseases 24 Miscellaneous 20 Oncology 9 Pediatric Ophthalmology 15
  1. 2 Apr 2021 9 min read

    Choroidal Neovascular Membrane

    Choroidal neovascular membrane (CNVM) is an ingrowth of new vessels from the choriocapillaris through a break in the outer aspect of Bruch’s membrane into the sub-pigment epithelial space. These new vessels are accompanied by fibroblasts, resulting in a fibrovascular complex that proliferates within the inner aspect of Bruch’s membrane. This fibrovascular complex can disrupt and destroy the normal architecture of the choriocapillaris, Bruch’s membrane, and the RPE. In addition, fibroglial and fibrovascular tissue can also disrupt and destroy the normal architecture of the photoreceptors and the remaining outer retina leading to the formation of a disciform scar. Within the subpigment epithelial space, the CNV can leak fluid and blood and may be accompanied by a serous or hemorrhagic detachment of the RPE. CNVM that remains restricted to the sub-RPE space is Type1 CNVM and when it becomes sub-retinal it is Type 2 CNVM. Clinical Features Symptoms of CNVM: Sudden onset of decreased vision

    Dr. Thomas Thachil
  2. 2 Apr 2021 16 min read

    Management of Subluxated cataract

    Zonular compromise complicates every step of cataract surgery and poses a serious challenge in terms of safety and visual outcome. When the lens is displaced from its normal position, it is considered subluxated if it remains in the pupillary area and luxated or dislocated if it is completely displaced from the pupil. Ectopia lentis is the term used to describe congenital dislocations.1 Lens displacements may be traumatic, heritable, and spontaneous.( Table 1) Table 1: Causes of Lens Dislocation Causes Features Traumatic Responsible for >50% lens displacements Heritable Associated systemic anomalies Marfans’s syndrome: Triad of skeletal, cardiovascular & ocular anomalies. Autosomal dominant. Generalized thinness and elongation of limbs, sternal deformities, kyphoscoliosis, joint hyperextensibility, low ratio between upper and lower segment, arachnodactyly, cardiopathy, aortic dilatation, dissecting aneurysm, mitral regurgitation. Ectopia lentis: B/L superotemporally, usually partial, r

    Dr. Ruchi Goel · Dr. KPS Malik
  3. 2 Apr 2021 12 min read

    Fun with Prisms in Ophthalmology

    What are prisms? Prisms are nothing but a portion of a refracting medium bordered by two plane surfaces that are inclined at a finite angle. Prisms have a thicker portion called the base of the prism and a tapering portion called the apex of the prism. Prisms are oriented with their apex towards the direction of deviation. What happens to light when it enters a prism? Light has particle and wave characteristics. When it travels through the thicker base of the prism, the particle form of light has to travel a longer distance than at the apex of the prism, this difference causes light to bend towards the base of the prism. The power of a prism to bend light is measured in prism diopters (PD). One prism diopter will shift light by 1 cm at 1m distance. Calibration of Prism Prisms made of glass are calibrated in Prentice position. They should be held with the back surface perpendicular to the line of sight. Plastic prisms and prism bars are calibrated by the angle of minimum deviation. They

    Dr. Manjula Jayakumar
  4. 2 Apr 2021 10 min read

    Seasonal Hyperacute Panuveitis (SHAPU)

    Introduction: Seasonal Hyperacute Panuveitis (SHAPU) is a mysterious eye disease with grave prognosis, reported only from Nepal. Though it was reported for the first time in 1975,1-3 no definite etiopathogenesis has been established to date. It occurs as an outbreak in certain regions of Nepal in a cyclical pattern during the autumn season and peaks during the winter season (August–December) only in odd years. Thus, after the first outbreak of 1975, the next outbreaks occurred in 1977,1979, 1981, and so on and the last outbreak was reported in 2019. SHAPU predominately occurs among children4 and the youngest reported case is a 38- day-male baby.5 No gender predilection has been identified in SHAPU.4 All cases are mainly immunocompetent with no prior history of systemic or ocular illness/trauma.4, 6 SHAPU is very devastating and generally leads to the loss of sight within a week, followed by cosmetic disfigurement due to phthisis bulbi, which can have a significant emotional impact on t

    Dr. Ranju Kharel (Sitaula)
  5. 2 Apr 2021 18 min read

    Epiretinal Membrane

    Epiretinal membranes(ERM) are acquired formation of semi-transparent cellular sheets on the macular surface, which are formed due to varied etiologies. These membranes have contractile properties, often leading to mechanical distortion of macula. The proliferation of ERM on the inner retinal surface along the internal limiting membrane was first described by Iwanoff in 1865 1. In 1971, Roth and Foos reported that in a series of autopsied eyes, ERM were present in 2 percent of patients aged 50 yr and in more than 20 percent of patients by age 75 yr2. Pearlstone reported an incidence of 6.4 percent in 1000 consecutive routine eye examinations in patients older than 50 yr, with 20 percent being bilateral 3,4. Other authors report bilateral involvement in 10 to 20% of cases5,6,7.The Los Angeles Latino Eye Study (LALES) found that of the participants with ERM, 19.9% had bilateral ERMs. The prevalence of ERM increased from 10.1% in persons 40 to 49 years of age to 35.7% in those aged 70 to 7

    Dr. Pravin Jain · Dr. P.N.Nagpal
  6. 2 Apr 2021 28 min read

    Vitrectomy: A Review

    INTRODUCTION Pars plana vitrectomy as a technique has revolutionized retinal surgery since its advent and initial report by Machemer et al 1. It allowed the removal of traction by an internal method, essential in retinal detachment procedures, as well as provided an active management modality for vitreous haemorrhage and opened the door for surgical intervention in a myriad of retinal pathologies. Since that time, the evolution of vitrectomy surgery has seen experimentation and implementation of smaller surgical instruments aimed at greater functionality and minimalization of ocular trauma. The basis of a sutureless pars plana sclerotomy was to stabilize intraocular pressure (IOP) during surgery, with a truly closed system, as well as reduce surgical time by removing the need for sutured wound closure. Wound and suture related complications such as leakage, irritation, and scleral pigmentary changes could also be avoided. Concerns regarding wound competence in a sutureless procedure ha

    Dr. Gaurav Paranjpe · Dr. Pravin Jain · +1 other
  7. 2 Apr 2021 10 min read

    Chemical Injuries of Eye - An Update.

    Introduction It is very frequent to encounter chemical injury in our routine ophthalmic practice. Most of the chemical injuries are minor, which heal without any squeal. Most are acids and alkalis. Alkali injuries are more common (nearly twice) than acids and are more severe in nature. It is of utmost importance to recognize the nature of chemicals for treating such patients. Here, we review the chemical injuries of the eye with their recent management update. Epidemiology Chemical burn 7.9-9% of all reported ocular burns. 23 -42% are bilateral. Young males are affected mostly. Most are industrial accidents (at workplace 60-70%, at homes 25-30%, criminal assault, and others comprise 2-3%) Sources of common chemicals Alkalis Acids 1.Ammonium hydroxide and Ammonia- fertilizers, laboratory refrigerator, household cleansing agent, bleaching powder 2. Sodium hydroxide-drain cleaner, soap 3. Potassium hydroxide- soap 3.Calcium hydroxide- plaster, cement, mortar, whitewash(chuna) 4.Magnesium

    Dr. Sushobhan Dasgupta · Dr. Tarannum Shakeel · +1 other
  8. 1 Apr 2021 19 min read

    Proliferative Diabetic Retinopathy

    Diabetic retinopathy (DR) is the leading cause of visual impairment worldwide. It almost accounts for 2.6% of treatable blindness globally (1). It is estimated that the overall prevalence of diabetic retinopathy is 34.6 % worldwide, while the prevalence of proliferative diabetic retinopathy (PDR) is 6.96% and that of vision-threatening DR (VTDR) is computed to be 10.2% (2). Currently, the prevalence of PDR in India is estimated to be 17% which is significantly higher compared to patients from other locations of Asia (3). Early detection and treatment is the only key to avoiding complications and risks of vision loss (4). But the major obstacle ahead of us in India is the failure to diagnose DR in early stages; as it is observed that only 18–35% of diabetics undergo ophthalmologic evaluation regularly (5). Pathogenesis Diabetic retinopathy is recognized as a neuro-vascular complication of diabetes. The triad of hyperglycemia, inflammation, and hypoxia along with retinal neurodegeneratio

    Dr. Aditya Kelkar · Dr. Mounika Bolisetty
  9. 1 Apr 2021 10 min read

    Cornea Edema : Ready Reckoner for the Post Graduates

    Corneal edema is defined as the increase in the thickness of cornea due to the accumulation of extracellular fluid in epithelium and stroma resulting in loss of corneal transparency. Pathophysiology: Cornea remains in a relatively dehydrated state maintaining a 78% hydration level. Corneal hydration depends on 5 factors. 1. Stromal swelling pressure (SP) This is the tendency of stroma to swell due to interfibrillary proteoglycans and other proteins. The normal stromal pressure is 55mmHg. Imbibition pressure (IP) – It is a negative pressure exerted by glycosaminoglycans by which fluid is drawn into the cornea. Intraocular pressure (IOP) = SP + IP 2. Barrier function The epithelium (Zonula occludens tight junction) offers twice the resistance to water flow compared to the endothelium (macula occludens tight junction) and the electrolyte resistance is 200 times higher in the epithelium than endothelium.1 3. Endothelial pump The endothelium pump function ensures, through active transport,

    Dr. Sumana Chatterjee
  10. 1 Apr 2021 44 min read

    Retinopathy of Prematurity

    Introduction First described in 1942, retinopathy of prematurity (ROP) is a vasoproliferative retinopathy affecting premature infants of low birth weight. As per the original description by Terry et al, this disease was labelled as retrolental fibroplasia (RLF) based on the hypothesis that it involved the proliferation of the embryonic hyaloid system[1] But Owens and Owens later described that in these infants, the hyaloid system was normal at birth and the RLF developed postnatally.[2] The term “retinopathy of prematurity” was coined later as the disease pathogenesis and clinical presentation got better understood. [3]In the 1950s, the association between supplemental oxygen and ROP pathogenesis was first established by controlled studies done in the neonatal intensive care units. {4,5] The spectrum of ROP ranges from mild cases that may resolve spontaneously with no visual impairment to advanced cases with bilateral irreversible blindness within the first few months of life. Epidemio

    Dr. Parveen Sen · Dr. Aditya Maitray