Aditya Verma

Does Neuronal Damage Precede Vascular Damage in Subjects with Type 2 Diabetes Mellitus and Having No Clinical Diabetic Retinopathy

Aim: To investigate the occurrence of neuronal damage, as the earliest change occurring, before the clinical evidence of diabetic retinopathy. Methods: 70 eyes of subjects with type 2 diabetes mellitus and with no evidence of diabetic retinopathy (cases) and 40 eyes of subjects with no diabetes mellitus (controls) were studied using spectral-domain OCT and microperimetry. The influence of age and gender on the outcome measures was also analyzed. Results: Age- and gender-matched subjects showed a decreased mean retinal nerve fiber layer thickness in cases when compared to the controls (27 vs. 33 µm; p = 0.018). Among the cases, subjects between 40 and 45 years of age showed a reduced mean central foveal thickness (175.1 vs. 198.1 µm; p = 0.05), mean retinal thickness in the central 6-mm fundus (260.5 vs. 275.3 µm; p = 0.006) and mean retinal nerve fiber layer thickness (29 vs. 39 µm; p = 0.036) when compared to the controls. However, no differences were noted in the microperimetry outcomes in cases when compared to the controls. The duration of diabetes and the glycemic control did not show any significant changes on the outcome measures in cases, except for a significantly lower mean retinal sensitivity in diabetics with glycosylated hemoglobin values <7% as compared to those with glycosylated hemoglobin ≥7% (14.1 ± 2.9 vs. 15.4 ± 1.7 dB; p = 0.027). Conclusion: The results suggest that there is some evidence of early neuronal damage particularly on spectral-domain OCT, before the clinical evidence of diabetic retinopathy, in subjects with type 2 diabetes mellitus.

Intraocular tissue migration of silicone oil after silicone oil tamponade: A histopathological study of enucleated silicone oil-filled eyes

Retrospective clinical and histopathological review of eight silicone oil-filled enucleated eyeballs using light microscopy was carried out in our department of ocular pathology during a period of six years. In all cases, silicone oil vacuoles, both free and incorporated within macrophages were seen in all the retinal layers. Silicone oil vacuoles were seen in the optic nerve, choroid, retinal pigment epithelium, corneal stroma, iris and ciliary body stroma, preretinal and subretinal membranes and retro-corneal membranes. Silicone oil migration could be seen in intraocular tissues as early as two months post surgery. There was no definite histopathological correlation between duration of tamponade and distribution of silicone oil vacuoles. Silicone oil vacuoles were seen in the optic nerve in eyes with neovascular glaucoma. Chronic inflammatory reaction was observed in the retinal tissue in the vicinity of silicone oil vacuoles.

Functional and anatomical outcomes after primary lens-sparing pars plana vitrectomy for Stage 4 retinopathy of prematurity

Background: While lens-sacrificing vitrectomy is the standard approach to manage Stage 5 retinopathy of prematurity (ROP), scleral buckling has been used to manage some cases of Stage 4. Lens-sparing vitrectomy was popularized by Maguire and Trese in selected cases of Stage 4 disease. Purpose: To assess the functional and visual outcomes after primary lens-sparing pars plana vitrectomy for Stage 4 ROP. Materials and Methods: In a retrospective, interventional, consecutive case series, the records of 39 eyes of 31 patients presenting with Stage 4 retinal detachment secondary to ROP who underwent primary two or three-port lens-sparing vitrectomy from January 2000 to October 2006 were evaluated. The outcomes studied at the final follow-up visit were the retinal status, lens and medial clarity and visual acuity. Favorable anatomical outcome was defined as the retinal reattachment of the posterior pole at two months after the surgery; and favorable functional outcome was defined as a central, steady and maintained fixation, with the child following light. Results: At mean follow-up of 15 months, 74% of the eyes had a favorable anatomical outcome with single procedure. The visual status was favorable in 63%. The lens remained clear in all the eyes at the last follow-up, and the media clarity was maintained in 87%. Intraoperative complications included vitreous hemorrhage, pre-retinal hemorrhage and retinal break formation. Conclusions: Lens-sparing vitrectomy helps to achieve a favorable anatomical and functional outcome in selected cases of Stage 4 ROP.

Choroidal granuloma as an initial manifestation of systemic sarcoidosis

Systemic sarcoidosis presenting as a choroidal nodule is a rare phenomenon, with limited reports in the past. We present a case of systemic sarcoidosis in a young adult male presenting as a solitary choroidal mass. The diagnosis was made based on elevated serum lysozyme, serum angiotensin-converting enzyme, negative Mantoux, and computed tomography (CT) scan of the chest. Ultrasound examination and fundus fluorescein angiography helped us to differentiate this lesion from choroidal melanoma. Magnetic resonance imaging (MRI) of brain was done to rule out neurosarcoidosis. Patient responded well to systemic steroid therapy, with marked resolution of the choroidal granuloma, and reduced size of mediastinal lymph nodes on repeat CT scan of the chest.

Influence of glycosylated hemoglobin on sight-threatening diabetic retinopathy: A population-based study

AIM To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sight-threatening diabetic retinopathy (STDR) in urban Chennai, Tamil Nadu, India. METHODS A total of 5999 individuals were enumerated from the Chennai metropolis. Of these, 1414 subjects with diabetes were included for data analysis in the study. STDR or non-STDR groups were classified based on the fundus photographs. HbA1c was measured (Bio-Rad DiaSTAT™ HbA1c Reagent Kit) by the liquid chromatography technique. RESULTS A statistically significant difference (p < 0.05) was noted in the duration of diabetes, gender, body mass index, HbA1c, micro- and macro-albuminuria between both non-STDR and STDR groups as compared to the no-diabetic retinopathy (DR) group. On multivariate analysis, HbA1c (non-STDR: odds ratio OR = 1.23; 95% confidence interval CI = 1.15-1.32; p < 0.0001; STDR: OR = 1.31 95% CI = 1.14-1.52; p < 0.0001) was found to be significantly associated with non-STDR and STDR when compared with the no-DR group. The Receiver Operating Characteristic analysis showed that the cut-off value of 8.0 had 75.6% sensitivity and 58.2% specificity with 64.9% maximum area under the curve. CONCLUSION HbA1c value >8.0% was significantly related with STDR. In a screening programme, the cut-off value of HbA1c >8.0% provided a maximum yield of STDR.

Intra-ocular expression of vascular endothelial growth factor (VEGF) and pigment epithelial-derived factor (PEDF) in a case of Eales’ disease by immunohistochemical analysis: a case report

We report a immunohistochemical study of expression of VEGF and PEDF in Eales’ disease. An enucleated eye from a patient with Eales’ disease and an age and sex-matched donor eyeball were subjected to immunohistochemical and histopathological analysis to study the expression of VEGF and PEDF in the retinal region. Strong positive anti-VEGF immunostaining was found around the vessel walls in the retina in the eyeball from the Eales’ disease patient compared with the donor control, from which it was almost absent. PEDF staining was detected in the normal donor eyeball retinal layers surrounding the blood vessels, and the photoreceptor and ganglion cell layer, whereas in the eyeball from Eales’ disease patient PEDF staining was restricted to the surrounding blood vessels. The strong expression of VEGF in eyes with Eales’ disease as opposed to weak expression of PEDF indicates the propensity of the disease to show neovascularization and recurrent hemorrhages.

Suprachoroidal collection of internal tamponading agents through a choroidal hole

We report two cases of significantly large choroidal holes following penetrating trauma that led to suprachoroidal migration of internal tamponading agents during repair of retinal detachments with proliferative vitreoretinopathy secondary to penetrating trauma. In the first case, choroidal hole was a direct result of the injury and was identified immediately after vitreoretinal surgery which was done for traumatic retinal detachment with hemorrhagic choroidal detachment. In the second case, the hole occurred over a period of several months after the repair of traumatic retinal detachment with silicone oil tamponade. This was attributed to progressive fibrosis exerting traction on the bare choroid/retinal pigment epithelium. Choroidal hole significant enough to cause suprachoroidal migration of internal tamponading agents is a very rare complication seen in eyes with posttraumatic retinal detachment with proliferative vitreoretinopathy.

Estimating the Rate of Non-Participation and Its Influence on the Study Results: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study Report 32

Purpose: To report the non-participation rates in a cross-sectional study, compare participants with non-participants, elucidate barriers for non-response and evaluate the influence of non-responders on the outcome measure. Methods: The Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study had 2 steps in which non- participation was possible. Step 1 was an estimation of fasting blood sugar at the participants’ homes, and step 2 a base hospital examination. The sociodemographic information was collected at the time of enumeration. The barriers against participation were noted at refusal. The data of the participants were compared with the urban Tamil Nadu population data from the 2001 census. Results: The non-participation rate was 3.6% in the field (step 1), and 13.9% at the base hospital (step 2). At step 1, older men and unemployed women had a lesser odds ratio for non-participation than younger age groups. At step 2, employment was significant for non-participation in men, and age between 50 and 59 years, illiteracy and unemployment in women. Conclusion: The barriers against participation differed between steps 1 and 2. The study participants were similar to the population of urban Tamil Nadu. Hence, the results of the study can be generalized to the urban Indian population.

Association of bilateral, multiple presumed retinal astrocytic proliferations with combined hamartoma of retina and retinal pigment epithelium in a 9-year-old male child with neurofibromatosis type 2

Neurofibromatosis type 2 (NF-2) is characterized by multifocal proliferation of neural crest-derived cells. The characteristics finding of NF-2 is bilateral vestibular schwannomas. Combined hamartoma of retina and retinal epithelium (CHRRPE) is another associated finding. A 9 year-old-male child presented with left eye decreased vision for 3 months. Visual acuity was 0.0 and 0.8 LogMAR in the right and left eye, respectively. Left fundus showed an elevated, pigmented lesion with surface wrinkling and vascular tortuosity suggestive of CHRRPE with multiple presumed retinal astrocytic proliferations in mid-periphery. He had multiple café-au-lait spots. Optical coherence tomography confirmed clinical findings. Magnetic resonance imaging brain showed bilateral acoustic neuroma. Recognition of this rare finding as presenting feature of NF-2 can lead to earlier diagnosis which is vital to appropriate surveillance and possible surgical intervention. It is recommended that children with CHRRPE be screened for NF-2.

To report a case of unilateral proliferative retinopathy following noncerebral malaria with Plasmodium falciparum in Southern India

The retinopathy in association with malaria fever described so far includes retinal hemorrhages, vessel changes, retinal discoloration/whitening and papilledema. Malaria retinopathy has been mostly described in severe cases, associated with Plasmodium falciparum, correlating the patho-physiology of retinal and cerebral manifestations. We report an unusual case of proliferative retinopathy as a manifestation of malaria fever, caused by P. falciparum with no cerebral involvement. The patient had features of unilateral retinal vascular occlusion with proliferative changes and vitreous hemorrhage. To the best of our knowledge, such a case has never been reported so far in the literature. This report highlights the possible occurrence of severe proliferative changes associated with malaria fever, which if diagnosed early can prevent possible blindness.