Hyperhomocysteinemia, a biochemical tool for differentiating ischemic and nonischemic central retinal vein occlusion during the early acute phase.

PURPOSE: The purpose of the study was to differentiate ischemic central retinal vein occlusion (CRVO) from nonischemic CRVO during the early acute phase using plasma homocysteine as a biochemical marker. METHODS: Fasting plasma homocysteine, serum vitamin B12, and folate levels were measured in 108 consecutive unilateral elderly adult (age >50 years) ischemic CRVO patients in the absence of local and systemic disease and compared with a total of 144 age and sex matched nonischemic CRVO patients and 120 age and sex matched healthy control subjects. RESULTS: Homocysteine level was significantly increased in the patients with ischemic CRVO in comparison with nonischemic CRVO patients (p = 0.009) and also in comparison with control subjects (p < 0.001). Analysis also showed that hyperhomocysteinemia was associated with increased incidence of ischemic CRVO (odds ratio, 18) than that for nonischemic CRVO (odds ratio, 4.5). Serum vitamin B12 and folate levels were significantly lower (p < 0.001) in CRVO patients compared to the control but were not significantly different between nonischemic and ischemic CRVO patients (p > 0.1). CONCLUSIONS: Hyperhomocysteinemia can be regarded as useful in differentiating nonischemic and ischemic CRVO during the early acute phase in absence of local and systemic disease in the elderly adult (age >50 years) population.

Penetrating keratoplasty restoring vision in an unusual case of corneal opacity following exposure to Euphorbia latex.

The milky sap of the Euphorbia plant is highly toxic and causes inflammation to the skin and eyes. Damage to the eye ranges from superficial epithelial defects, keratoconjunctivitis, mild to moderate corneal edema, anterior uveitis, Descemet membrane folds, raised intraocular pressure and rarely corneal opacity in severe untreated cases. Here we report a case of visual restoration by optical penetrating keratoplasty in a patient with severe corneal opacity following exposure to Euphorbia latex.

Comparison of autologous in situ blood coagulum versus sutures for conjunctival autografting after pterygium excision.

Our aim was to compare the efficacy and safety of autologous in-situ blood coagulum versus sutures for attaching conjunctival limbal autografts (CAG) among patients undergoing primary pterygium excision over a period of 1 year. Thirty-two eyes of 32 patients with primary pterygium were randomly divided in into two groups: group I (16 eyes) underwent CAG with 10-0 monofilament nylon sutures and group II (16 eyes) underwent CAG with patient's own in-situ blood coagulum acting as bioadhesive or fixative followed by bandaging for 48 h. Patients were followed up postoperatively on the 2nd day, 1 week, 2 weeks, 4 weeks, and 12 months. All the surgeries were done by the same surgeon. Graft success, recurrence rate, operating time, patient comfort, graft retraction or any other complication were studied. The duration of surgery was significantly less (P < 0.001) in group II (mean duration 15 ± 2 min) than group I (mean duration 67 ± 2 min). Postoperative symptoms were fewer for group II than group I. Rate of recurrence was equal in both groups (one patient in each group, 6.25 %). But complications regarding graft failure and graft retraction were more common in group II (two patients, 12.5 %) than group I (one patient, 6.25 %); however, the difference was not statistically significant (Z = 0.61). Thus, autologous in-situ blood coagulum is a useful method for graft fixation in pterygium surgery with shorter operating time and less postoperative discomfort.

Comparison of ex vivo cultivated human limbal epithelial stem cell viability and proliferation on different substrates.

Ocular surface injury causes serious vision-related problems especially when limbal stem cells are affected. Treatment lies in the transplantation of viable donor cells. Various substrates are used for the cultivation of limbal epithelial stem cells. In the present study, viability and proliferation of ex vivo cultured limbal epithelial stem cells were examined on a variety of substrates like collagen type IV, direct plastic Petri plate, intact amniotic membrane and denuded amniotic membrane. Viability and proliferation of cells were examined by colorimetric assay and [(3)H]-thymidine incorporation study. Furthermore, matrix metalloproteinase is known to be a key regulator in stem cell migration and proliferation. This enzyme activity was studied by gelatinolytic zymography. It was found from this study that although human limbal epithelial stem cells could be cultivated on different substrates such as collagen type IV, direct plastic Petri plate, intact amniotic membrane and denuded amniotic membrane, maximum growth and proliferation was observed when cultured on intact amniotic membrane. The number of patients suffering from limbal epithelial stem cell deficiency is large compared to donor tissues available for transplantation. Hence, increased cell viability and proliferation is required to serve more patients.

Hyperhomocysteinemia, as an independent risk factor for retinal venous occlusion in an Indian population.

Total plasma homocysteine was analysed in 64 cases of retinal vein occlusion (RVO) of which 24 cases of central retinal vein occlusion (CRVO) and 40 cases of branch retinal vein occlusion (BRVO) and compared with 45 age and sex matched control. Homocysteine was significantly increased in RVO cases in respect to control (P < 0.001). Analysis also revealed that prevalence of rise of plasma homocysteine was more in cases of CRVO (OR = 13) than that of BRVO (OR = 5.03).

An impression cytology based study of ocular surface in an urban population.

To assess the health of ocular surface in a defined urban population, conjunctival goblet cell density and degree of surface squamous metaplasia were utilized as study tools. Two thousand names of those aged between 20 and 79 years from the 2006 electoral register in ward number 63 of Kolkata Corporation area were initially selected. Normal healthy human volunteers without any history of ocular surface disorder were recruited and divided into five age-groups. Impression cytology samples were obtained from interpalpebral part of bulbar conjunctiva from all the participants fixated and stained by a single observer. A stratified, clustered, disproportionate, random sampling method was used. The software used in the statistical analysis was EPI Info. The tests applied were t test and ANOVA. A variation in the number of goblet cells according to gender (women having less cells) and age (20-30 years group having the highest number of cells) was found. Those working outdoors were found to have fewer goblet cells compared to those who stay indoors. The majority of the people had grade 1 cytological appearance in both males and females. There was no statistically significant difference in Nelson's grading with age. People using coal and kerosene to cook were found to have a smaller goblet cell density than those who cooked on LPG or those who did not cook at all. Besides age and sex, environmental factors like the method of cooking and occupational variables (like outdoor activity, prolonged period of computer use, etc.) modify the health of the ocular surface. The results of this study will help put these findings into perspective as public health problems.

Boston keratoprosthesis restoring vision in an unusual case of end-stage limbal stem cell deficiency following exposure to Euphorbia latex.

We report the functional outcome of a patient who had undergone Boston keratoprosthesis type I for extensive ocular surface damage caused by latex of Euphorbia. The milky sap or latex of the Euphorbia plant is highly toxic and an irritant to the skin and eye. Damage to the eye ranges from mild to severe corneal edema, epithelial defects, anterior uveitis, secondary elevated intraocular pressure and, rarely, limbal stem cell deficiency with corneal neovascularization. A restrospective review was conducted of this patient for more than 1 year. During this period he was given subconjunctival bevacizumab injection to regress the corneal vascularization without much benefit, before finally performing Boston keratoprosthesis type I. The patient was evaluated periodically for both anatomical and visual outcome. At the end of 1-year follow-up the keratoprosthesis is well retained with a best-corrected visual acuity of 20/40 in the affected eye.

Effect of cord blood serum on ex vivo human limbal epithelial cell culture.

Limbal cell transplantation is an efficacious procedure for rehabilitation of visual acuity in patients with severe ocular surface disorders. Cultivation of limbal epithelial stem cell with fetal bovine serum for transplantation has been a promising treatment for reconstructing the ocular surface in severe limbal stem cell deficiency caused by Steven Johnson syndrome, chemical or thermal injury. This technique of "cell therapy" has been accepted worldwide but the cost of cultivating the cells for transplantation is high. The objective of this study was to investigate the effect of cord blood serum in place of fetal bovine serum on the growth of human limbal epithelial cell culture. Our group has experimented with human cord blood serum which was obtained free of cost from willing donors. The use of human cord blood serum in place of fetal bovine serum for ex vivo culture of limbal stem cell has helped us in reducing the cost of culture. Fresh human limbal tissues from donor cadavers were cultured on intact and denuded amniotic membrane. Cells were proliferated in vitro with cell culture media containing human cord blood serum. Reverse transcription-polymerase chain reaction and immunofluorescence cytochemistry of cultured human limbal epithelial stem cell was done for characterization of the cells.

Correlation of macular thickness and posterior hyaloid change following bevacizumab and triamcinolone in diffuse diabetic macular edema in middle-aged patients.

UNLABELLED: To compare changes in posterior vitreous detachment (PVD) following intravitreal injection of bevacizumab and triamcinolone in diffuse diabetic macular edema in middle-aged type 2 diabetes patients and to correlate this change with change in central macular thickness (CMT). DESIGN: cross sectional study. Fifteen consecutive patients treated by intravitreal bevacizumab (group A) and ten patients treated by intravitreal triamcinolone (group B). Institutional study carried out by retrospective analysis of patient registers including serial optical coherence tomography (OCT) images at baseline, and after 1 and 4 months. A central macular thickness (CMT) and vitreomacular relationship was noted on OCT. PVD was graded on a linear scale (0-4). Change in grade of PVD was correlated with change in CMT at each follow-up. At month 4, the decrease in mean CMT from baseline was 51.2 µ (P = 0.000) and 45 µ (P = 0.022) in group A and group B, respectively, with no significant difference between the two groups (P = 0.874). A change in grades of PVD from baseline to month 4 was significant in both group A (P = 0.001) and group B (P = 0.004) with no significant difference between the two groups (P = 0.906). A significant correlation between change in PVD and reduction of CMT was observed in group A (P = 0.011) but not in group B (P = 0.315). Both bevacizumab and triamcinolone caused a significant reduction in macular thickness and a significant change in grade of PVD. Change in PVD played an influential role in the reduction of macular thickness following bevacizumab.

Effect of manganese toxicity on pigment content, Hill activity and photosynthetic rate of Vigna radiata L. Wilczek seedlings.

Effect of different concentrations, viz. 10(-4) M, 5 x 10(-4) M, 10(-3) M and 5 x 10(-3) M of manganese sulphate (MnSO4, 7H2O) on chlorophyll, carotenoid pigment content and photosynthesis of mungbean seedlings was examined Progressive increase in manganese sulphate concentration upto 5 x 10(-3) M brought about a progressive decrease in total chlorophyll and chl a content. Chl b content changed very little by excess manganese treatment. Total carotenoid pigment content decreased considerably in comparison to control with every concentration of manganese sulphate tried here. Hill activity of chloroplasts isolated from leaves of mungbean seedling and rate of photosynthesis in terms of CO2 uptake showed progressive reduction along with the increase in concentration of the manganese.