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Purpose To evaluate the effect of sildenafil on selenite-induced cataract formation in a rat model. Methods Twenty-six Wistar rat pups were divided into four groups. Seven pups received only selenite on postpartum day 10 (group 1), 7 pups received selenite and additional high dose sildenafil on postpartum day 10 (group 2), 6 pups received selenite and additional low dose sildenafil on postpartum day 10 (group 3), and 6 pups received only saline (group 4, control). All pups were examined for the presence of cataract under the microscope, starting from the day their eyes opened. Nitrite oxide metabolites, advanced oxidation protein products and total sulfhydryl levels were evaluated in both serum and lenticular samples. Results In group 3, the extent of lens opacification was significantly less than that of selenite-injected untreated rats (group 1) (p

To examine the influence of lens opacity and refraction on the measurement of retinal vascular fractal dimension (Df). Optic disc photographs (right eyes) of 3654 baseline Blue Mountains Eye Study participants (aged 49-97) were digitized. Retinal vascular Df was quantified using a computer-based program. Summated severity scores for nuclear, cortical and posterior subcapsular (PSC) cataract were assessed from lens photographs. Refraction data were converted to spherical equivalent refraction (SER), as sum spherical plus 0.5 cylinder power. Axial length was measured at 10-year follow-up examinations using an IOL master. Mean Df of the retinal vasculature was 1.444±0.023 for 2859 eligible participants. Increasing lens opacity scores were associated with significant reduction in Df (β=-0.0030, p0.0001). Both cortical and PSC cataract involving central lens area were associated with reduced Df, after controlling for confounding factors (p(trend) ≤0.0105). Increasing myopia severity was associated with reduced Df after adjusting for lens opacity scores and other confounders (p(trend) 0.0001). The slope of Df decrease per SER reduction was 0.0040 in eyes with SER≤-4D, compared to -0.0016 in eyes with SER-4D. For axial length quintiles, there were no significant differences in mean Df in all groups except a reduction in the fifth quintile (axial length ≥24.15mm) (all p0.05). Ocular media opacity independently influenced retinal vascular Df measurement, but we found no evidence supporting any refractive axial magnification effect on this measure. Myopic refraction ≤-4D was associated with a reduction in Df, suggesting rarefaction of retinal vasculature associated with high myopia.

The aim of the presented study was to establish if occupational exposure to infrared (IR) radiation increases the risk of developing cataract, and to correlate the lens findings to the degree of exposure. The eyes of 208 IR-exposed workers and 208 controls, all from 6 Swedish iron and steel manufacturing plants, were examined. An increased prevalence of wedge-shaped opacities was found in IR-exposed persons 60 years of age and older. This type of lens opacity is normally considered to be a purely senile change. Acceleration of senile changes by IR radiation is suggested. Stratification of the material with regard to exposure was made on different grounds, but failed to show a dose-effect-correlation.

The role of free-radical-induced lipid peroxidation (LPO) in the development of human lens opacity was investigated. 130 human crystalline lenses impaired with cataract of various etiology (senile, traumatic, complicated cataracts) at different stages of cataract development as well as 18 transparent human lenses were studied. Primary products of LPO (diene conjugates), secondary products (ketodienes) and the end products (Schiff bases) were distinctly accumulated in cataractous lenses. Initial stages of cataract were characterized by the accumulation of primary LPO products, while in the latest stages there was a prevalence of fluorescent end products of LPO. It was concluded that the accumulation of polar hydroxy groups in the lipid bilayer of plasma membranes of lenticular fibers is one of the possible causes of their injury in cataracts.

The exfoliation syndrome as a risk factor for lens opacification was investigated with pairwise comparisons of lens opacity, visual acuity, refraction, and anterior chamber depth in 126 eyes of 63 patients with unilateral exfoliation syndrome, and in 84 eyes of 42 patients with unilateral capsular glaucoma. As compared with fellow eyes, the exfoliative eyes showed poorer visual acuity (p < 0.05) and more frequent occurrence of subcapsular cataract (2% vs 8%). Compared with the fellow eyes the lenses in the capsular glaucomatous eyes were more opaque, whether without pilocarpine (p < 0.05), or with pilocarpine treatment (p < 0.0001). Visual acuity was poorer (p < 0.01), refraction more myopic (p < 0.05), and anterior chamber depth less (p < 0.05) in the capsular glaucomatous eyes with pilocarpine treatment. Thus, there are slight changes in the lenses of the exfoliative eyes, the cataractous lens changes being more advanced in the capsular glaucomatous eyes.

We compared pre- and postoperative visual acuities in 45 cataract patients without ocular pathology except lens opacity (group 1) and 20 patients with ocular pathologies and lens opacity (group 2) using Variable Contrast Visual Acuity Charts. Charts 1 and 4 have 90% contrast; chart 4 has white optotypes on a black background (reverse polarity), charts 2 and 3 have 15% and 2.5% contrast, respectively. The mean preoperative visual acuities of groups 1 and 2 measured with the high-contrast Landolt optotypes ranged from 0.02–0.80 and 0.22–0.40, respectively. Visual acuity improvements between the pre- and postoperative periods ranged from 1.37–1.61 and 0.52–1.24 octaves in groups 1 and 2, respectively, with the different charts. Visual acuity improvement was poorest with chart 3. The group 1 mean preoperative visual acuity measured with chart 2 was 1.11 octaves lower than with chart 1. In group 2, the visual acuity reduction was 1.81 octaves. The relation between the visual acuities measured with the high-contrast intermediate-contrast optotypes are important for predicting postoperative visual acuity improvement. An abnormal contrast acuity profile may indicate the presence of additional ocular pathologies.

Cataract progression after trabeculectomy was investigated in a study of 47 eyes with exfoliative glaucoma (ExG) and in 20 eyes with primary open-angle glaucoma (POAG). Cataract progression was assessed from the need for cataract extraction, deterioration of visual acuity byor = 2 Snellen lines, myopic change in the refraction and increase in the lens opacity value, measured with a Lens Opacity Meter 701. Measurements were made 6 and 12 months after trabeculectomy and at the follow-up visit at 26 +/- 11 months. ExG, age, hypotony (IOPor = 5 mm Hg) lastingor = 5 days and early postoperative IOP rise30 mm Hg were observed to be risk factors for cataract progression. In pairwise analysis of 14 patients, in which the unoperated eye served as the control, a myopic change of refraction was the most frequent indicator for a change in the structures of anterior segment, possibly indicating cataract progression.

We measured back light scattering of the human lens with the Lens Opacity Meter 701 in order to determine whether it can be used for objective assessment of lens opacities in various types of cataracts. One-hundred and twenty-seven eyes of 127 individuals were examined including 43 healthy volunteers in various age groups and 84 patients with cortical, nuclear, posterior subcapsular or mixed lens opacities. Almost 90% of the total variation in the light scatter values was accounted for by age in non-cataractous eyes. Mean scatter value of every cataract group was statistically significantly higher than that of age matched healthy controls (p less than 0.0001). Highest scatter values were measured in cortical cataracts while the mean values of other types of cataract were not statistically significantly different from each other. The regression between light scatter and visual acuity was statistically significant for each cataract group. However, large variation of visual acuity was found with scatter values below 60. The results indicate that the Interzeag Lens Opacity Meter is able to identify cataractous and non-cataractous eyes and discern at least advanced cortical cataracts from other types of lens opacities.

Purpose To assess the impact of human crystalline lens opacification and yellowing, similar to that observed in patients with cataracts, on retinal vessel blood oxygen saturation measurements using custom manufactured soft contact lenses. Methods Ten healthy, non-smoking individuals were enrolled for this study. All subjects underwent digital blood pressure measurements, assessment of non-contact intra-ocular pressure, pupil dilation and retinal vessel oximetry using dual-wavelength photography (Oximetry Module, Imedos Systems). To simulate lens changes, three different contact lenses were inserted, one to simulate opacities followed by two more lenses to simulate different levels of lens yellowing (Cantor & Nissel). Results The measurements obtained showed an opposite change in arterial and venous oxygen saturation and optical density ratio across conditions, resulting in a statistically significant difference in arterial minus venous oxygen saturation value (p = 0.003). However, this difference was only significant for the ‘opacity’ condition but not for the ‘yellowing’ conditions. Conclusion Lenticular changes such as cataracts can impact on spectrophotometric analysis in particular dual-wavelength retinal vessel oximetry. Hence, lenticular assessment and cataract grading should be considered when assessing elderly individuals and patient groups developing cataract earlier in life such as those suffering from diabetes mellitus.

Purpose To evaluate the effect of lens opacities in quality of images and reproducibility of retinal nerve fiber layer (RNFL) thickness measurements using Spectralis Optical Coherence Tomography (OCT). Methods Fifty eyes of 50 subjects (25 men and 25 women; aged from 62 to 88 years) underwent three 360° circular scans centred on the optic disc by the same experienced examiner using the “RNFL Fast” Glaucoma Application and the “RNFL-N Fast” Axonal Application of Spectralis OCT instrument one month before and one month after cataract surgery. Comparison between the two visits and changes in reproducibility (using intra-class correlation coefficients and coefficients of variation) were analyzed. The quality of images was also compared between both visits. Results RNFL and RNFL-N differences were detected between both visits for average thickness, temporal and nasal quadrants (p

Purpose To evaluate the difference of straylight value depending on the location of lens opacity and to study whether the straylight measurement is useful in deciding the surgery of early cataract. Methods 139 cataractous eyes were classified into posterior subcapsular opacity type, anterior subcapsular opacity type and diffuse nucleosclerosis type. Straylight values of each groups were measured. Straylight values of 28 patients(28 eyes) who complained visual disturbance despite good visual acuity were measured and compared with 28 control eyes. Postoperative straylight values and best corrected visual acuities of 28 patients were measured and compared with the preoperative values. Results Posterior subcapsular opacity group showed significantly high straylight values(p=0.000). Mean straylight values of 28 eyes(28 patients) and 28 control eyes were 2.04±0.91 and 1.56±0.29 respectively(p=0.002). This was well matched to the difference of self-reported visual quality scores of each group(45.1 points and 29.8 points). Postoperative straylight values decreased significantly than preoperative straylight values(p=0.000) in 28 patients. Self-reported visual quality was well related to the decrease of straylight values(from 45.1 points to 28.2 points). Conclusion Straylight value was significantly high in posterior subcapsular lens opacity. Straylight is found to have added value for visual quality assessment and it can be useful to determine the time of cataract surgery in early cataractous eyes.

Purpose To review the results and complications of combined phacoemulsification and vitrectomy in phakic patients. Methods Retrospective review of 412 consecutive phakic patients who underwent phacoemulsification and vitrectomy for primary rhegmatogenous retinal detachment (RRD) (71), stages 2 to 4 full thickness macular holes (FTMH) (86), idiopathic epiretinal membrane (ERM) (237), diabetic macular edema (DME) (18) . Results Lens opacity was absent or mild in 85% of patients. Reattachment rates for primary RRD after one procedure were 86% and final reattachment rates were 95% . Macular hole closure rate was 95% for holes under 500 microns. There was significant improvement in the median logMAR visual acuity from 1.6 preoperatively to 0.48 postoperatively for the retinal detachment patients ,from 0,59 preoperatively to 0,28 for the idiopathic epiretinal membrane , from 0,93preoperatively to 0,4 in full thickness macular holes and from 0,96 to 0,60postoperatively in diabetic macular edema. Postoperative complications included fibrinous uveitis (2%), IOL/iris capture secondary to gas overfill (1.1%), and posterior capsule opacification (8%). Conclusion Combined phacoemulsification and vitrectomy is a safe and desirable option in the management of phakic patients with vitreoretinal pathologies that warrant vitreous surgery, even in the absence of significant lens opacity.