Abstract
Purpose: :
To investigate whether the improvement of visual field (VF) sensitivity observed following uncomplicated cataract extraction (CE) affects the ability to detect VF progression in glaucoma patients using pointwise linear regression analysis (PLR).
Methods: :
Retrospective observational cohort. Treated, established glaucoma patients (optic disc damage and VF abnormalities) with ≥8 24-2 SITA VF tests seen between January 1999 and December 2009 were included. VF progression was evaluated using automated PLR (PROGRESSOR, Medisoft Ltd., Leeds, UK). A VF progression endpoint was defined as at least 2 adjacent test points in the same hemifield progressing >1.0 dB/yr at p<0.01. VF, MD and PSD values were compared using the VF tests performed before and after CE. Global rates of sensitivity change (dB/yr) and number of eyes reaching a progression endpoint were compared between eyes that underwent CE and no other surgery during the VF sequence (Group A) and eyes that did not undergo any surgery (Group B) during the same period.
Results: :
348 eyes of 348 patients (mean age, 64.8±12.8 yrs; 88.5% European descent; mean baseline MD, -6.4±4.7 dB) were evaluated. Group A had 71 eyes (20.4%) and Group B 277 (79.6%). Group A patients were older than those in Group B (72.1±9.7 vs. 62.9±13.0 yr, p<0.01). There was no significant difference between groups regarding baseline MD (p=0.75), CCT (p=0.72), or mean follow-up IOP (p=0.25). There was a non-significant change in mean MD and mean PSD following surgery (-7.6±4.6 to -6.8±4.2 dB, p=0.27; and 5.8±43.2 to 6.2±3.4 dB, p=0.50, respectively). Groups A and B showed similar velocities of sensitivity change (-0.35±0.4 vs. -0.35±0.6 dB/yr, p=0.98) even after adjusting for differences in age (p=0.27). Group A reached progression endpoints as often as Group B (30.9% vs. 21%, p=0.10). CE did not influence VF endpoint in the multivariate model after adjusting for differences in age (OR=1.40, p=0.26).
Conclusions: :
VF global indices did not change significantly following uncomplicated CE. VF sensitivity changes observed following CE do not affect the ability of PLR to detect VF progression. Uncomplicated cataract surgery should not be considered an exclusion criterion when applying automated PLR to detect VF progression in glaucoma patients.
Keywords: visual fields • cataract