[Changes in monochromatic higher-order aberrations in different pupil sizes with accommodation in young emmetropes].

OBJECTIVE: To study the effect of accommodation on monochromatic higher-order aberrations in different pupil sizes in the young emmetropes. METHODS: Intervention trial design was used in the study. The monochromatic aberrations were measured in 12 eyes from 12 undulated young emmetropes in 4.0 mm, 3.0 mm, and 2.0 mm pupil sizes with a ray tracing wavefront aberrometer under accommodative stimuli from 0 to 4.00 D. RESULTS: RMS values of total high-order aberrations (HOAs), total coma, total higher-order astigmatism, total spherical, and total trefoil aberrations significantly decreased as pupil size decreased in the relax state. In 4.0 mm, 3.0 mm, and 2.0 mm pupil sizes, the average root mean square (RMS) value of total coma was the highest item of HOAs in the relaxed state. With accommodation up to 3.00 D, the RMS of HOAs remained constant but changed significantly at 4.00 D stimulation (P <0.05) in all these three pupil sizes. The 4th spherical aberration decreased and changed from positive to negative with increasing accommodation over 4.0 mm size, whereas it remained positive under all accommodative levels over the 3.0 mm and 2.0 mm zones, and no trend was found. The 3rd order trefoil 0 changed from negative to positive with increasing accommodation, with 4.0 mm, 3.0 mm, and 2.0 mm pupil sizes. CONCLUSIONS: In 4.0 mm, 3.0 mm, and 2.0 mm pupil sizes, under accommodative stimuli from 0.00 to 4.00 D, dramatical trends amongst the HOAs, spherical, coma, and trefoil aberrations were demonstrated. Most of the higher-order aberrations induced by accommodation deserves further investigation. Simple elimination of the higher-order aberrations will be replaced by the optimization of aberrations.

Inducible nitric oxide synthase is involved in the oxidation stress induced by HIV-1 gp120 in human retina pigment epithelial cells.

BACKGROUND: The human immunodeficiency virus-1 (HIV-1) envelope glycoprotein gp120 has been implicated in the development of AIDS-associated retinopathy. The present study tested the hypothesis that gp120 may induce oxidative stress including up regulation of inducible nitric oxide synthase (iNOS) and production of malondialdehyde (MDA) and nitric oxide (NO) to mediate retinopathy in retinal pigment epithelial (RPE) cells. METHODS: Human RPE cell line D407 was cultured and treated with gp120. HIV-1 gp120 protein induced lipid peroxidation product MDA. NO production and iNOS expression were examined in vitro by spectrophomtometry, real-time PCR, Western blotting, and confocal microscope. RESULTS: Addition of gp120 was able to induce RPE cells to produce NO and MDA in time- and dose-dependent manners (P < 0.05). Similarly, gp120 was also capable of up-regulating iNOS mRNA and protein in D407 cells in time- and dose-dependent manners. CONCLUSIONS: Gp120 induces oxidative stress in D407 cell by stimulating MDA and NO production, which is mediated by up-regulating iNOS expression. Gp120 may mediate oxidation stress in AIDS-associated retinopathy.