Refraction Simplified for the Post Graduates
The optics of the eye normally creates a clear image by refracting rays of light to focus on the retina. Imperfections in this optical system create aberrations and thus blurred images. The goal is to analyze them and devise a means to eliminate them. Lower order aberrations are primarily refractive errors when parallel rays of light after refracting, do not focus on the retina with accommodation ...Read More
Fungal Keratitis: A Review for the Post-Graduates
Introduction Fungal or mycotic keratitis is a leading cause of ocular morbidity, opacification and preventable blindness.1 The approximate annual incidence of fungal keratitis in India is said to be 11.3/10,000 population.2 Frequently it is caused by filamentous fungi (Aspergillus, Fusarium, Curvularia) in the tropical areas, while in temperate regions it is predominantly caused by Candida species...Read More
How do we treat inflammatory CNVM ?
Inflammatory choroidal neovascular membranes (CNVM) cause an acute and significant visual loss 1,2. Mostly affecting eyes with posterior or panuveitis, the chronic recurrent nature of inflammation further worsens the visual prognosis in these eyes, such as serpiginous like choroiditis, punctuate inner choroidopathy (PIC), multifocal choroiditis, Vogt-Koyanagi-Harada (VKH) disease, presumed ocular ...Read More
Duanes Retraction Syndrome Made Ridiculously Simple
Synonyms: Stilling–Turk–Duane syndrome. Duane Retraction Syndrome is a type of congenital cranial dysinnervation which occurs in 1-4% of strabismus cases. It has varied presentation mostly involving variable horizontal duction deficits, with narrowing of the palpebral fissure and globe retraction on attempted adduction, occasionally accompanied by upshoot or down shoots Etiopathogenesis Various th...Read More
Introduction The eyeball development begins early in the 4th week of intrauterine life with formation of optic vesicle (a diverticulum) from diencephalon. The structure of eyeball is shown in Figure 1. Various components of eyeball are derived from the following sources: Retina, iris and optic nerves are derived from optic vesicle that arises from neuroectoderm of diencephalon. Lens and corneal ep...Read More
Panophthalmitis: A Ready Reckoner for Postgraduates
Introduction Panophthalmitis is a severe ocular and orbital condition which can lead to phthisis bulbi or may necessitate evisceration. Severe inflammation of the anterior and posterior segments is frequently accompanied by microbial keratitis, necrotizing scleritis, and perforation or rupture following trauma. The disease develops rapidly and the prognosis is poor. The management of patients with...Read More
1. Science behind Multifocal Intraocular Lens (MFIOL) Multifocal intraocular lenses are IOLs which can separate incoming light into two or more foci, thus resulting in multiple coexisting retinal images. At any given point, only one of the images (distance, intermediate or near) is the sharpest, and hence selected by the brain for visualisation. This concept is known as simultaneous vision. The vi...Read More
Angioid streaks are visible irregular crack-like dehiscences in Bruch’s membrane that are associated with atrophic degeneration of the overlying retinal pigmented epithelium. Despite 50 % of cases being idiopathic, this condition grabs attention as it requires good history taking and workup to determine the cause. Historical background The first description of angioid streaks was provided in 1889 ...Read More
Paediatric Retinal Vascular Diseases
Introduction This chapter will discuss pediatric retinal vascular diseases like Persistent Fetal Vasculature, Familial Exudative Vitreo Retinopathy and Incontinentia Pigmenti Persistent Fetal Vasculature (Persistent Hyperplastic Primary Vitreous) Definition Persistent hyperplastic primary vitreous (PHPV) is a congenital ocular disorder in which fetal vasculature does not regress after birth. It is...Read More
Tips on Management of Intraocular Foreign Body
Introduction Open globe injuries (OGI) are associated with retained intraocular foreign body (IOFB)in 18 to 41% of cases1. Retained IOFB is an important cause of visual morbidity and blindness, especially in working-age population with male predominance. Majority of the IOFBs are related to trauma at workplace1. Types of IOFB Majority of IOFB are metallic1,2. It is followed by organic IOFB and met...Read More