Quantifying microstructural changes in retinitis pigmentosa using spectral domain - optical coherence tomography.

BACKGROUND: Most patients of established retinitis pigmentosa (RP) have subnormal peripheral vision and heavily rely on central vision for their daily activities. Central visual acuity is dependent on photoreceptor survival at the macula. Identification of structural changes that precede visual loss is essential. The aim of this study was to correlate the Spectral Domain-Optical Coherence Tomography (SD-OCT) characteristics with visual acuity in patients with typical RP. METHODS: This was a retrospective, observational case series of 224 eyes of 113 RP patients conducted a tertiary eye care center. SD-OCT imaging was done for all eyes. Central retinal thickness (CRT), photoreceptor outer segment length (PROS), foveal outer segment pigment epithelial thickness (FOSPET) and ellipsoid zone (EZ) extent were measured. A new variable, FOSPET-PROS ratio (FPR), obtained by dividing FOSPET by PROS is defined and correlated to corrected distance visual acuity (CDVA) in logMAR using linear regression. RESULTS: Out of 113 patients, 71 were males and 42 females. Mean age of the patients was 35.4 ± 15.1 years. Mean CDVA was 0.33 ± 0.25 logMAR with no difference between the genders. Mean CRT (218.74 ± 83.5 µm) and FPR (1.63 ± 0.22) significantly correlated to CDVA with a correlation coefficient of r = - 0.139 (p = 0.048) and r = 0.842 (p = 0.0001), respectively. FOSPET (mean = 71.15 ± 13.8 µm) and PROS (mean = 44.85 ± 12.5 µm) did not show a significant correlation to CDVA, independent of FPR. CONCLUSIONS: Retinal microstructural changes on SD-OCT, especially the FPR, can be used as a surrogate marker to monitor disease progression in the central retina in degenerative diseases like RP.

Prevalence of diabetes mellitus and hypertension among Indian glaucoma patients and evaluation of systemic therapy.

To study the prevalence and systemic control and evaluate the adequacy of therapy of diabetes mellitus (DM) and hypertension (HT) in glaucoma patients visiting a tertiary care eye facility at a university hospital. Consecutive cases with primary open-angle glaucoma (POAG) or primary angle-closure glaucoma (PACG) attending the outpatient services were evaluated for the presence of DM and HT and any systemic/ocular medications being taken were recorded. Of 615 glaucoma cases evaluated, 281 (45.7 %) were POAG and 334 (54.3 %) were PACG. The mean age was 58.19 ± 10.8 years with males comprising 60.5 % of the study group. Two hundred and ninety-two (47.5 %) glaucoma patients had HT and 181 (29.4 %) had DM, including 97 (15.8 %) patients who had both. One hundred and thirty-three (47.3 %) patients with POAG and 159 (47.6 %) patients with PACG had HT. Ninety-seven (34.5 %) POAG patients and 84 (25.1 %) PACG patients were diabetics. One hundred and sixty-one (55.1 %) HT patients had blood pressure above control levels and 88 (48.6 %) diabetics had uncontrolled blood sugars. Twenty-eight (9.6 %) patients with HT were found to be taking combined systemic and topical ß-blocker therapy. A large majority of adult glaucoma patients had concurrent systemic disease, which was not adequately controlled. Patients were using systemic medications with known interactions with ocular hypotensive medications. This study highlights the unmet need for better coordination between ophthalmologists and physicians to improve the overall health of glaucoma patients.

Drug-induced Angle-Closure Glaucoma.

Drug-induced angle-closure glaucoma is an important entity for the ophthalmologist as well as the general physician as it represents a preventable cause of potential blindness. This brief review highlights the fact that a high index of suspicion, in a susceptible individual followed by confirmation on appropriate imaging modality (UBM, ultrasound or anterior segment OCT) can alleviate the threat to sight and also help to institute appropriate therapy.