Choroidal thickness in diabetic patients of Indian ethnicity.

Purpose: To evaluate choroidal thickness (CT) change in various grades of diabetic retinopathy (DR) in comparison to age‑matched healthy subjects. Methods: This prospective observational study included 227 eyes of 125 subjects with diabetes (study group: 58 females) and 197 eyes of 110 age‑matched healthy subjects (control group: 66 females). Collected data included age, gender, duration of diabetes, glycemic control, comprehensive ocular examination, fundus photography, and CT measurement on spectral domain ocular coherence tomography using enhanced depth imaging. Results: Mean age in the study group was 57.0 ± 9.37 years (43–73 years). The mean age was 41.48 ± 5.43 years in the control group. Subjects with diabetes with (252.8 ± 55.6 microns) and without (261.71 ± 51.8 microns) retinopathy had significantly thinner choroids when compared to the control group (281.7 ± 47.7 microns; P = 0.032). Seventy‑four of 227 eyes did not have any evidence of DR, 89 eyes had features of nonproliferative diabetic retinopathy (NPDR), and 33 eyes had treatment naïve proliferative diabetic retinopathy (PDR). Thirty‑one PDR eyes had received previous laser photocoagulation. Subjects with diabetes without retinopathy had a greater subfoveal choroidal thickness (SFCT) than subjects with diabetes with retinopathy (P < 0.001). Eyes with PDR (243.9 ± 56.2 microns) had thinner SFCT than those with NPDR (238.98 ± 111.23 microns). There was no difference in the SFCT between treated (laser photocoagulation done; 251.784 ± 103.72 microns) and treatment naïve PDR (258.405 ± 89.47 microns, P = 0.23). Conclusions: Control eyes had greater SFCT compared to subjects with diabetes, with and without retinopathy. The thinning progressed with increasing severity of DR. Choroidal thinning may contribute to DR pathogenesis.

Choroidal thickness profile in healthy Indian children.

Purpose: The purpose was to study choroidal thickness and its profile based on location in healthy Indian children using enhanced depth spectral‑domain‑optical coherence tomography (SD‑OCT). Methods: In this cross‑sectional observational study 255 eyes of 136 children with no retinal or choroidal disease were consecutively scanned using enhanced depth SD‑OCT. Eyes with any ocular disease or axial length (AXL) >25 mm or < 20 mm were excluded. A single observer measured choroidal thickness from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500‑microns intervals up to 2500 microns temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between choroidal thickness at various locations and age, AXL, gender and spherical equivalent (SEq). Results: Mean age of the subjects was 11.9 ± 3.4 years (range: 5–18 years). There were 62 Females and 74 males. The mean AXL was 23.55 ± 0.74 mm. Mean subfoveal choroidal thickness was 312.1 ± 45.40 μm. Choroid was found to be thickest subfoveally, then temporally. Age, AXL and SEq showed a significant correlation with choroidal thickness, whereas gender did not affect choroidal thickness. Conclusion: Our study provides a valid normative database of choroidal thickness in healthy Indian children. This database could be useful for further studies evaluating choroidal changes in various chorioretinal disorders. Age and AXL are critical factors, which negatively correlated with choroidal thickness.

Choroidal thickness profile in healthy Indian subjects.

Purpose: The aim was to study choroidal thickness (CT) and its profile based on location in healthy Indian subjects using Cirrus high definition (HD) optical coherence tomography. Materials and Methods: A total of 211 eyes of 115 healthy subjects with no retinal or choroidal disease were consecutively scanned using Cirrus HD 1 line raster scan mode without pupillary dilation. Eyes with any ocular disease or axial length (AXL) >24 mm or <20 mm were excluded. Experienced technician measured CT from the lower border of the retinal pigment epithelium (RPE) to the lower border of choroid. CT was measured from the posterior edge of the RPE to the choroid/sclera junction at 500‑μm intervals up to 3000 μm temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between CT at various locations and age, AXL, spherical equivalent, and macular thickness. Results: Mean age was 42.8 ± 13.6 years. Mean AXL was 22.84 ± 0.78 mm. Median spherical equivalent was 0.16 ± 0.64 D. Mean central macular thickness was 216.4 ± 30.03 μm. Choroidal was thinnest nasally and thickest subfoveally. On multivariate regression, age was the most significant factor affecting subfoveal CT (P = 0.000). Regression analysis showed an approximate decrease in CT of 1.18 μm every year. Conclusions: Our study provides CT profile in Indian healthy subjects in various age groups. CT depends on its location, subfoveal being the thickest and nasal being the thinnest. Age is a critical factor, which is negatively correlated with CT.

Validation of Assay Indicating Method Development of Simvastatin in Bulk and its Tablet Dosage form by RP-HPLC.

A novel, simple and economic reverse phase high performance liquid chromatography (RP-HPLC) method has been developed for the estimation of Simvastatin in bulk and tablet dosage form with greater precision and accuracy. Separation was achieved on Develosil ODS HG-5 RP C18, (150cmx4.6mm i.d. 5m) column in isocratic mode with mobile phase consisting of acetonitrile :phosphate buffer(pH 3.0) (85:15) with a flow rate of 1 mL/min. The detection was carried out at 236 nm. The retention time of Simvastatin was found to be 5.84 min. The method was validated as per ICH guidelines.Linearity was established for Simvastatin in the range 10 – 100 μg / ml with R2 value 0.99. The percentage recovery of Simvastatin was found to be in the range 99.19-99.67 %. The high recovery and low relative standard deviation confirm the suitability of the proposed method for the estimation of the drug in bulk and tablet dosage forms. The LOD and LOQ were found to be 0.341 and 1.023 μg/ml respectively.Validation studies demonstrated that the proposed RP-HPLC method is simple, specific, rapid, reliable and reproducible for the determination of Simvastatin for Quality Control level.

Excised radicle tips as a source of genomic DNA for PCR-based genotyping and melting curve analysis in cotton.

Genomic DNA isolation in cotton is complicated because of the presence of secondary metabolites that are inhibitory to PCR amplification. We report here that radicle tips, but not other parts of cotton seedlings, yield high-quality DNA that is readily amenable for PCR. The radicle-tip-excised seedlings retain viability because of the formation of adventitious roots. We demonstrate the utility of this method in distinguishing homozygotes from heterozygotes in a cotton breeding population and in hybrid seed purity testing.