Case report of a uniocular topography guided laser-assisted in situ keratomileusis enhancement following an incorrectly treated astigmatic axis

A 23-year-old male presented to us wanting spectacle removal for cosmetic purposes. He underwent bilateral wavefront optimized (WFO) laser-assisted in situ keratomileusis (LASIK) on the Alcon Wavelight^® EX-500 excimer laser with an incorrectly treated astigmatism axis for left eye due to a manual data entry error in the laser. WFO LASIK treats the sphere and cylinder only. LASIK enhancement with topographic-guided ablation resulted in the elimination of all refractive errors and gave excellent results. Wavelight^® topographic-guided treatment can perform two separate layers of correction in the same ablation: The first is to treat the corneal irregularities for the higher order aberration (HOA) removal, the second one meant to treat the sphere and cylinder if indicated.     

Comparative redox status in alcoholic liver disease and nonalcoholic fatty liver disease

Purpose Altered redox status has been implicated in pathogenesis of alcoholic liver disease (ALD) as well as in nonalcoholic fatty liver disease (NAFLD). This study was planned to find the relative role of redox status in these two diseases. Methods A total of 44 patients with ALD and 32 patients with NAFLD and 25 apparently healthy controls were included in the study. Redox status was estimated by measuring oxidative stress (superoxide dismutase (SOD) and lipid peroxidation products as thiobarbituric acid reactive substances (TBARS)) and antioxidant status (ferric reducing ability of plasma (FRAP) and vitamin C). Results TBARS level was raised significantly in both ALD (3.5 (2.3–9.4) vs. 1.8 (0.5–4.1) nmol/ml; P = 0.0001) and NAFLD (5.1 (1–10.2) vs. 1.82 (0.51–4.1) nmol/ml; P = 0.0001) as compared with controls, but was not different between ALD and NAFLD. SOD was significantly higher in ALD as compared to NAFLD (2.4 (1.3–7.8) vs. 0.68 (0.05–19.1) U/ml; P = 0.0001) and controls (1.12 (0.01–3.5) U/ml; P = 0.001). FRAP was lower in ALD as compared with NAFLD (345.4 (56–615.9) vs. 434.1 (197.6–733.3) μmol of Fe⁺² liberated; P = 0.001) but similar to that of controls (340.9 (141.5–697.5) μmol of Fe⁺² liberated). Conclusions ALD patients have a higher degree of redox imbalance as compared with NAFLD patients     

Structure and function in rhodopsin: the role of asparagine-linked glycosylation.

Rhodopsin, the dim light photoreceptor of the rod cell, is an integral membrane protein that is glycosylated at Asn-2 and Asn-15. Here we report experiments on the role of the glycosylation in rhodopsin folding and function. Nonglycosylated opsin was prepared by expression of a wild-type bovine opsin gene in COS-1 cells in the presence of tunicamycin, an inhibitor of asparagine-linked glycosylation. The non-glycosylated opsin folded correctly as shown by its normal palmitoylation, transport to the cell surface, and the formation of the characteristic rhodopsin chromophore (lambda max, 500 nm) with 11-cis-retinal. However, the nonglycosylated rhodopsin showed strikingly low light-dependent activation of GT at concentration levels comparable with those of glycosylated rhodopsin. Amino acid replacements at positions 2 and 15 and the cognate tripeptide consensus sequence [Asn-2-->Gln, Gly-3-->Cys(Pro), Thr-4-->Lys, Asn-15-->Ala(Cys, Glu, Lys, Gln, Arg), Lys-16-->Cys(Arg), Thr-17-->Met(Val)] showed that the substitutions at Asn-2, Gly-3, and Thr-4 had no significant effect on the folding, cellular transport, and/or function of rhodopsin, whereas those at Asn-15 and Lys-16 caused poor folding and were defective in transport to the cell surface. Further, mutant pigments with amino acid replacements at Asn-15 and Thr-17 activated GT very poorly. We conclude that Asn-15 glycosylation is important in signal transduction.     

Ab externo technique for accurate haptic placement of transscleral sutured posterior chamber intraocular lenses.

A modified technique is presented for transscleral suture fixation of posterior chamber intraocular lenses for aphakic correction in cases with inadequate capsular support. An ab externo approach for suture externalization is described that minimizes intraocular manipulation and facilitates accurate placement of haptics in the ciliary sulcus, thereby reducing the risk of lens tilt and decentration. This technique eliminates intraocular suture knots and reduces the amount of time the globe is open during surgery by creating two intraocular suture loops in preparation for posterior chamber intraocular lens placement before creating a limbal incision.