Andrew Braganza

Dimensions of the foveal avascular zone using the Heidelberg retinal angiogram-2 in normal eyes.

Purpose: The purpose was to study the dimensions of the foveal avascular zone (FAZ) using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany). Materials and Methods: An observational study of the FAZ area and circumference was done with fundus fluorescein angiography (FFA) using HRA-2 in 31 normal individuals. The FAZ was studied using both contrast-adjusted and nonadjusted methods. Contrast adjustment was done to obtain better visualization of the finer capillaries around the fovea enabling more precise measurements of the FAZ in normal eyes. Results: The mean area of the FAZ calculated by the contrast-adjusted method was 0.2753 mm2 (±0.074) and the mean circumference was 2.22 mm (±0.048). By the conventional method, the area and circumference of the FAZ were 0.6241 mm2 (±0.177) and 3.23 mm (±0.454), respectively. Conclusion: The measurements of area and circumference of FAZ using contrast-adjusted methods were significantly smaller than the conventional method.

An "epidemic" of post cataract surgery endophthalmitis by a new organism

We report a case series of endophthalmitis by an organism hitherto not reported in the eye. Nineteen of 63 cataract patients operated in a high-volume setup were urgently referred to us with acute onset of decreased vision one to two days following cataract surgery. All patients had clinical evidence of acute endophthalmitis with severe anterior chamber exudative reaction. Vitreous tap was done in three representative patients and repeated intravitreal injections were given as per established protocol. The vitreous sample from all three patients grew Enterobacter amnigenus Biogroup II, a gram-negative bacillus which, to the best of our knowledge, has never been reported in the eye. With prompt and accurate microbiological support, it was possible to salvage 17 of these eyes without performing vitrectomy. Six eyes regained 6/200 or better vision.

Does the ISNT Rule Apply to the Retinal Nerve Fiber Layer

Purpose:To determine whether the ISNT rule (Inferior>Superior>Nasal>Temporal) or the “IST” rule (Inferior>Superior>Temporal) can be applied to the peripapillary retinal nerve fiber layer (RNFL) thickness as measured using Heidelberg Retinal Tomography (HRT) and Optical Coherence Tomography (OCT). Materials and Methods:This was a cross-sectional study of 189 normal and 42 glaucomatous eyes. RNFL thicknesses measured in different quadrants using HRT and OCT were compared to determine the percentage of eyes obeying the ISNT and IST rule. Results:The HRT-measured mean RNFL thickness in normal eyes showed that 25.9% obeyed the ISNT rule and 70.4% conformed to the “IST” rule. The “IST” rule was able to identify normal eyes better (P=0.040), but had a poor sensitivity (45%) and specificity (70%) to diagnose glaucoma. The OCT-measured average RNFL thickness showed that 47.1% of normal eyes obeyed the ISNT rule and 58.7% conformed to the “IST” rule. Exclusion of the nasal sector also increased the number of glaucomatous eyes conforming to the IST rule (31% obeyed the ISNT rule and 50% obeyed the IST rule). Sensitivities and specificities of the ISNT and the IST rules for OCT-quantified RNFL ranged from 42% to 77%. Conclusions:A larger number of normal eyes obeyed the IST rule compared with the ISNT rule for the RNFL thickness measured by HRT and OCT. Exclusion of the nasal sector from the analysis (IST rule) marginally improved the specificity in diagnosing glaucoma at the cost of the sensitivity, making neither of these parameters (ISNT and IST) likely to be useful clinically.

Vitreous opacities in phacolytic glaucoma

BACKGROUND AND OBJECTIVE To report five cases of vitreous opacification in phacolytic glaucoma (PG). PATIENTS AND METHODS The records of patients with PG were retrospectively reviewed. A total of 135 eyes with PG were studied to determine the presence of vitreous opacification. RESULTS Five eyes with PG demonstrated opacification of the vitreous, which was first noted at surgery and confirmed postoperatively. All patients had had symptoms of PG for 7 days or more (mean +/- SD, 10.6 +/- 2.4 days) before they sought medical attention. Three eyes had a hypopyon on preoperative examination; two of these eyes showed refractile crystals in the anterior chamber. The opacities resolved spontaneously in all five eyes over a period of 12 weeks and interfered with visual activity only in the immediate postoperative period. CONCLUSION Vitreous opacification in PG is a self-limited process that may not require surgical intervention unless more rapid visual rehabilitation is desired. The vitreous opacification probably results from an exaggeration of the process causing the anterior chamber reaction.

Bilateral choroidal metastasis from carcinoma of the submandibular gland.

Metastatic tumor is the most common uveal malignancy. However, choroidal metastasis from a salivary gland neoplasm is extremely rare. We report a case of bilateral, multifocal choroidal metastasis from carcinoma of the submandibular gland.

Ocular clinical profile of patients with pseudoexfoliation syndrome in a tertiary eye care center in South India.

Purpose: To study the clinical profile of pseudoexfoliation (PEX) syndrome in a hospital setting. Materials and Methods: A case series of patients with PEX, with and without glaucoma attending the general ophthalmology clinic of a tertiary care center in South India. All patients underwent a complete ophthalmologic evaluation including recording diurnal variation of tension (DVT), gonioscopy and visual field assessment. Results: The study cohort comprised 529 patients (752 eyes). There were 296 (56%) females. The highest number of patients (261 patients) was from the age group between 60 and 69 years. Of 752 eyes, 57.8% eyes had unilateral PEX and 72% had established PEX. Gonioscopy showed open angles in 98.1% of eyes. Intraocular pressure (IOP) greater than 21 mmHg in at least 1 of 4 measurements was recorded in 5.7% eyes. DVT was normal in 96.4% of unilateral PEX eyes, similar to fellow non-PEX eyes. Pseudoexfoliation glaucoma occurred in 1.9% of eyes and 4.7% of eyes were glaucoma suspects. There was no correlation between the stage of PEX and increased IOP. Mean central corneal thickness of PEX eyes was 522 ± 27μ. Pupillary dilatation in 90.5% eyes with early PEX was ≥ 7 mm. Conclusions: A small percentage of PEX eyes had raised IOP, and the number of eyes with glaucomatous optic neuropathy was even lower. PEX eyes did not demonstrate wide fluctuations in IOP. No correlation was found between raised IOP and stage of PEX. There was good pupillary dilatation in early stage PEX eyes suggesting that all PEX eyes may not have poor pupillary dilatation and related complications.

Primary glaucoma in three siblings with Werner syndrome

Ageing is a polygenic process manifested by alopecia, grey hair, loss of hearing, skin changes, cardiovascular diseases, osteoporosis, type-2 diabetes, neurodegeneration, autoimmune disorders and malignancies. Ophthalmic manifestations include cataract, glaucoma, macular degeneration and retinal vascular disorders. Manifestations of ageing are a consequence of interaction between genetic and environmental factors. Progeria was originally described by Jonathan Hutchinson (1886) and Hastings Gilford (1904). The Hutchinson-Gilford progeria syndrome is also known as childhood progeria. In Werner syndrome (WS), signs and symptoms manifest after the age of 10. Other disorders associated with premature ageing are Cockayne syndrome, Rothmund Thomson syndrome, acrogeria, metageria and neonatal progeroid syndrome. WS is an autosomal recessive disorder with mutations in the WRN gene. Affected individuals are normal until the first decade of life. There is lack of pubertal growth spurt in the second decade followed by the development of features of ageing. Clinical manifestations include limited growth, alopecia and a taut scleroderma-like skin with a small face and jaw. They have small fragile bodies and underdeveloped secondary sexual characteristics. Mental development is not affected. There is an increase in urinary excretion of hyaluronic acid and connective tissue matrix abnormalities. The most common ocular association is cataract. We document ophthalmic findings in three siblings with WS born to parents of second-degree consanguinity. After physical examination by an internist and endocrinologist, the diagnosis of WS was based on diagnostic criteria described by Nakura et al. All of them had alopecia, proportionate dwarfism (average height – 132.6 cm), low weight (average weight – 19.33 kg), high-pitched voices, small bird-like facies, tight skin and greying of hair with normal mental development. The eldest, a 24-year-old female sibling presented at 22 years with cataract and intraocular pressure (IOP) not exceeding 19 mmHg with disc and field changes characteristic of glaucoma (Fig. 1a). The brother aged 19 presented with high IOP (>30 mmHg), open angles and cataract with early disc and field changes (Fig. 1b). He was diagnosed to have open-angle glaucoma and underwent cataract surgery, intraocular lens implantation and trabeculectomy in both eyes. The third sibling, a 17-year-old female, had a presentation (Fig. 1c) similar to her older sister. Both sisters underwent conjunctival sparing cataract surgery and are on medical treatment for control of IOP for normal tension glaucoma (NTG). Diagnosis of glaucoma was established by disc changes, field defects on automated perimetry and nerve fibre layer thinning on optical coherence tomography (Fig. 1). Cataract is the most common ocular manifestation of WS. Corneal decompensation, cystoid macular oedema and unplanned filtering bleb have been reported following cataract surgery in these patients. Although glaucoma is an age-related disease, there are no reports of primary glaucoma in WS in the available literature. Iijima et al. have reported glaucoma associated with uveitis in a patient with possible WS. The open angle glaucoma in the male sibling could possibly be due to the increased hyaluronic acid (an unsulfated glycosaminoglycan) levels and its subsequent deposition in the trabecular meshwork resulting in impaired aqueous drainage, similar to the glycosaminoglycan deposition causing steroid induced glaucoma. Increased hyaluronic acid also causes collagen hardening and sclerosis of arteriolar walls. The resulting compromise on perfusion of the optic nerve head as well as probable connective tissue abnormalities at the lamina cribrosa could be the reason for the NTG as manifested in the female siblings. However, because all three siblings have glaucoma, the question arises as to whether some other common mechanism of glaucoma exists in these siblings. Familial predisposition is seen in primary open-angle glaucoma but not in NTG, and hence this appears unlikely. The common underlying genetic abnormality of WS would be the more likely cause. To investigate this, genetic studies of the patients and their close family members is necessary. Additionally, biochemical and histopathological analysis of ocular tissues obtained by biopsy or at surgery would be contributory. Unfortunately, these have not been possible in our patients. We describe a hitherto unreported association of primary glaucoma in three siblings with Werner syndrome. We postulate connective tissue abnormalities involving the trabecular meshwork and lamina cribrosa as well as compromised vascular supply to the optic nerve head as the possible causes for glaucoma in WS. Appropriate surgical and medical management has ensured preservation of functional vision in these patients. The frequent presentation of advanced cataract with normal IOP makes detailed disc evaluation difficult in these patients. It is therefore important to actively look for, diagnose and monitor glaucoma both before and after cataract surgery. Further genetic, histopathological and biochemical studies are necessary to establish the pathogenesis and mechanism of glaucoma in these patients.