Mohideen Abdul Kader

Retinal nerve fibre layer thickness measurements in normal Indian population by optical coherence tomography

PURPOSE To obtain retinal nerve fibre layer thickness measurements by optical coherence tomography (OCT) in normal Indian population. MATERIALS AND METHODS Total of 118 randomly selected eyes of 118 normal Indian subjects of both sex and various age groups underwent retinal nerve fiber layer thickness analysis by Stratus OCT 3000 V 4.0.1. The results were evaluated and compared to determine the normal retinal nerve fiber layer thickness measurements and its variations with sex and age. RESULTS Mean +/- standard deviation retinal nerve fiber layer thickness for various quadrants of superior, inferior, nasal, temporal and along the entire circumference around the optic nerve head were 138.2 +/- 21.74, 129.1 +/- 25.67, 85.71 +/- 21, 66.38 +/- 17.37 and 104.8 +/- 38.81 microm, respectively. There was no significant difference in the measurements between males and females and no significant correlation with respect to age. CONCLUSION Our results provide the normal retinal nerve fiber layer thickness measurements and its variations with age and sex in Indian population.

Optic disc morphometry with optical coherence tomography: Comparison with planimetry of fundus photographs and influence of parapapillary atrophy and pigmentary conus.

PURPOSE Optical coherence tomography (OCT) is an established method for visualising macular pathology and for measuring the thickness of parapapillary retinal nerve fibre layer. The purpose of the present study was to compare OCT measurements of the optic disc with those obtained by planimetry of fundus photographs and to investigate whether OCT measurements are influenced by the amount of parapapillary atrophy or pigmentary conus at the disc margin. MATERIALS AND METHODS Eighty-two eyes of 41 randomly selected Asian-Indian subjects were included. The mean age was 44.2+/-14.3 years (mean+/-SD). All eyes underwent optic disc assessment by OCT (fast optical disc protocol) and digital 20 degree disc photos.. Planimetry of the discs were performed by outlining the disc and the cup. The amount of parapapillary atrophy (zone beta) was quantified as the number of clock-hours around the disc with adjacent parapapillary atrophy. The same procedure was performed to quantify the amount of pigmentary conus around the disc. RESULTS Mean+/-SD disc size and mean+/-SD cup size in OCT measurements (2.37+/-0.51, 1.29+/-0.55) were significantly smaller than in photographic planimetry (2.83+/-0.62, 1.56+/-0.5: P<0.001, P<0.001). Optic discs with parapapillary atrophy (P=0.2) in their relative difference of disc sizes between OCT and planimetry. Similarly, optic discs with pigmentary conus (n=12) and discs without pigmentary conus (n=70) did not differ significantly (P=0.65). The relative difference in disc size between the two measurement modalities did not correlate with the amount of parapapillary atrophy (r=-0.17, P=0.29) or with the amount of pigmentary conus (r=-0.04, P=0.9). CONCLUSION OCT analysis of the optic disc produces significantly smaller parameters, compared to the established method of optic disc planimetry. Neither presence, nor extent of parapapillary atrophy zone beta and pigmentary conus seems to produce a systematic error in measurements of disc size with the OCT.

Anterior segment optical coherence tomography documentation of a case of topiramate induced acute angle closure

We present a case report of a 31-year-old female patient who presented to us with a 1 day history of acute bilateral eye pain, blurred vision and headache. She was found to have a myopic shift, raised intraocular pressure (IOP) and shallow anterior chambers in both eyes. She had been commenced on oral topiramate 1 week previously. A number of investigations, including anterior segment optical coherence tomography (AS-OCT) were done and a diagnosis of topiramate induced bilateral acute angle closure (TiAAC) was made. Topiramate was discontinued and she was managed with topical and oral antiglaucoma medications, topical steroids and cyclopegics. Her symptoms subsided dramatically at the next follow-up. The AS-OCT documentation revealed lucidly the improvement in her anterior chamber depth and anterior chamber angle parameters. Her IOP decreased, her myopic shift showed reversal and her AS-OCT findings revealed gross improvement in all the parameters angle opening distance, trabecular iris space area and scleral spur angle. This case report clearly shows with AS OCT documentation the changes which occur in the anterior segment in a case of TiAAC.

Evaluation of Angle Closure as a Risk Factor for Reduced Corneal Endothelial Cell Density

Purpose: Acute angle closure attacks are frequently accompanied by corneal edema. However, little is known about corneal endothelial cell status at different stages of angle closure. Here, we compared endothelial cell density (ECD) in unoperated eyes with that in eyes with open angles (OAs) and various stages of angle closure disease. Materials and Methods: The study was conducted at Aravind Eye Hospitals in India. Masked examiners performed gonioscopy to classify each eye as follows: (1) OA, (2) primary angle closure suspect, or (3) primary angle closure (PAC)/primary angle closure glaucoma (PACG). Specular microscopy was performed and differences in ECD were analyzed using hierarchical models. Results: A total of 407 patients and 814 eyes were studied, including 127 (15.6%), 466 (57.3%), and 221 (27.1%) with PAC/PACG, primary angle closure suspect, and OA, respectively. Participants were predominantly female (69.8%) and the mean age was 49.2 (SD: 8.6) years. Lower ECD was observed with increasing age [&bgr;=−6.3 cells/mm2; 95% confidence interval (CI), −9.3 to −3.3, per year; P<0.001], greater iridotrabecular contact [&bgr;=−15.6 cells/mm2; 95% CI, −28.3 to −2.9, per quadrant of contact; P=0.016), and shallow (<2.5 mm) anterior chamber depth (&bgr;=−40 cells/mm2; compared to deeper ACs (≥2.5 mm), 95% CI, 78.9-1.1; P=0.044). In age-adjusted analyses, angle closure suspects had lower ECD than OA eyes (&bgr;=−54.7 cells/mm2; 95% CI, −47.8 to −85.3; P=0.018), although PAC/PACG eyes were not significantly different from OA eyes (&bgr;=−18.6 cells/mm2; 95% CI, −85.9 to 2.5; P=0.058). Conclusion: In untreated eyes, only mild, clinically insignificant decrement in ECD was noted with angle closure.

Angle Closure Phenotypes in Siblings of Patients at Different Stages of Angle Closure

Financial Disclosures: The authors made the following disclosures: M.Y.K.: Consultant e Alcon, Allergan, Aerie Pharmaceuticals, Forsight Vision 5, and Tempest Ocular; Other e Alcon, Allergan, Aerie Pharmaceuticals, Forsight Vision 5, Tempest Ocular; Grants e Alcon, Allergan, Clarvista Medical, New World Medical, AMO, Glaukos, Aerie Pharmaceuticals, outside the submitted work; Patent e Clarvista, Glaukos, AMO, Shapetech; Grant funding NEI. P.Y.R.: Grants e National Eye Institute, Research to Prevent Blindness, outside the submitted work. L.K.S.: Other e Allergan, Sensimed, New World Medical; Grants e Alcon, outside the submitted work. J.R.S.: Grants e Alcon, Allergan, Bausch & Lomb, Glaukos, Regeneron, outside the submitted work. Supported by the Slater Family Endowment (M.Y.K.). The sponsor or funding organization had no role in the design or conduct of this research.

Clinical and genetic characterization of a large primary open angle glaucoma pedigree

ABSTRACT Purpose: To both characterize the clinical features of large primary open angle glaucoma (POAG) pedigree from a village in southern India and to investigate the genetic basis of their disease. Materials and methods: Eighty-four members of a large pedigree received complete eye examinations including slit lamp examination, tonometry, gonioscopy, and ophthalmoscopy. Some were further studied with perimetry. Those diagnosed with POAG were tested for disease-causing mutations in the myocilin and optineurin genes with Sanger sequencing. Results: Fourteen of 84 family members were diagnosed with POAG, while eight were clinically judged to be POAG-suspects. The family structure and the pattern of glaucoma in the pedigree are complex. Features of glaucoma in this pedigree include relatively early age at diagnosis (mean 50 ± 14 years) and maximum intraocular pressures ranging from 14 to 36 mm Hg with a mean of 23 mm Hg ± 6.5 mm Hg. Patients had an average central corneal thickness (mean 529 ± 37.8 microns) and moderate cup-to-disc ratios (0.74 ± 0.14). No mutations were detected in myocilin, optineurin, or TANK binding kinase 1 (TBK1). Conclusions: We report a five-generation pedigree with a complex pattern of POAG inheritance that includes 22 POAG patients and glaucoma suspects. Although the familial clustering of POAG in this pedigree is consistent with dominant inheritance of a glaucoma-causing gene, mutations were not detected in genes previously associated with autosomal dominant glaucoma, suggesting the involvement of a novel disease-causing gene in this pedigree.

Open angle glaucoma in a case of Type IV Ehler Danlos syndrome: A rarely reported association

A 26-year-old male presented to us with defective vision in the left eye. He had best corrected visual acuity (BCVA) of hand movement (HM) in right eye and 6/9 in left eye. He had ptosis with ectropion in both eyes and relative afferent pupillary defect (RAPD) in right eye. Intraocular pressure (IOP) was 46 and 44 mmHg in right and left eye, respectively. Fundus showed glaucomatous optic atrophy (GOA) in right eye and cup disc ratio (CDR) of 0.75 with bipolar rim thinning in left eye. Systemic examination showed hyperextensible skin and joints, acrogeria, hypodontia, high arched palate, and varicose veins. He gave history of easy bruising and tendency to fall and history of intestinal rupture 5 years ago for which he had undergone surgery. He was diagnosed as a case of Type IV Ehler-Danlos syndrome (EDS) with open angle glaucoma. He underwent trabeculectomy in both eyes. This is a rare case that shows glaucoma in a patient of EDS Type IV. Very few such cases have been reported in literature.