Influence of Lens Opacities on Visual Field Indices

Abstract

This report presents the results of a study designed to verify the influence of lens opacities on the visual field indices. Four age-matched groups of subjects were considered: healthy volunteers, glaucomatous patients without lens opacities, cataractous patients without glaucoma and glaucomatous patients with lens opacities. The quantification of lens opacities was performed with the Lens Opacity Meter 701 instrument. The visual field indices were obtained automatically from the G1 program of the Octopus system. The statistical analysis of the results (coefficient of correlation) has shown that only the visual field indices that correspond to uniform and diffuse loss of light sensitivity were influenced by the presence of cataract. On the contrary, the visual field indices that indicate local irregularities of the threshold were not significantly influenced by the presence of lens opacities.

Quantification and Measurement of Human Lens Opacities Using the Lens Opacity Meter

“…This means that the instrument can only detect and quanti fy lens opacity when the central area of the lens is involved [3]. When opacities occurred out side the central area of the lens (posterior sub capsular and cortical cataracts), there was no correlation between LOM values and visual acuity.…”

“…Cataracts not affecting the central area of the lens (posterior subcapsular and cor tical cataracts) are not detected by the instru ment. Moreover, in such forms a slight move- ment of the light beam will produce different LOM values [3].…”

Change in Perimetric Global Indices Following Cataract Surgery in Patients with Glaucoma

“…This is measured as a reduction in the mean deviation. 6 Cataract surgery in eyes with only mild glaucoma-related visual field defects has been shown to result in significant improvement in the mean deviation. As Per (Table 3) MD: Improvement in MD is seen even with a small improvement in BCVA in our study.…”

Glaucoma Progression Detection: Agreement, Sensitivity, and Specificity of Expert Visual Field Evaluation, Event Analysis, and Trend Analysis

“…Nonetheless, the clinician must be aware of the many factors which may significantly influence perimetry results and lead to an incorrect clinical decision. Among those are uncorrected refractive errors (2, 3), patient's experience (4), pupil size (5), individual response (6, 7), and presence of cataract (8–11) or other pathologies. Particular effort must be given to distinguish intertest variability from true glaucoma progression.…”