Abstract
Purpose:
To prospectively examine the hypothesis that surgical intraocular pressure (IOP) reduction leads to enhancement of visual field (VF) sensitivity in glaucomatous eyes.
Methods:
Patients with uncontrolled IOP on maximal medical therapy requiring trabeculectomy or aqueous drainage device implantation who met eligibility criteria were prospectively enrolled. Medically treated glaucoma patients enrolled in the Advanced Imaging in Glaucoma Study with stable treatment during serial follow-up were selected as a control group. Eyes with visual acuity <20/30, corneal or retinal pathology or unreliable VFs were excluded. The VF series used for the analysis consisted of 2 baseline (BL) preoperative VFs and 3 follow-up (FU) postoperative VFs at 1, 2, and 3 months. The same number of VFs measured within an 18-month interval was used for control eyes. The VF was divided into 16 central and 36 peripheral test locations. Significant change was defined as a change from the mean of the 2 BL VFs exceeding the 95% test-retest confidence limits at that sensitivity. The number of significantly changing locations per eye was compared between groups using a Poisson generalized estimating equation (GEE) model. Changes in mean (MD) and pattern standard deviation (PSD) from the mean BL fields were compared between groups using a linear GEE model.
Results:
Thirty eyes (BL MD -7.6±4.9 dB) of 30 surgically treated glaucoma patients (age 68.3±18.4 yrs) and 41 eyes (BL MD -5.6±4.2 dB) of 28 stable controls (age 67.4±7.3 yrs) were enrolled. Mean time interval between the BL and FU3 was greater in control eyes (18.3±2.91 months; p<0.001) vs. surgical eyes (4.9±1.96 months). Postoperative IOP (9.9±4.7mmHg) was decreased at FU3 compared with BL (18.0±6.7 mmHg; p<0.001) in the surgical eyes. Control eyes had similar IOP at FU3 and BL (13.7±3.2 vs. 13.7±2.6 mmHg, p=0.92). At FU3 the number of test locations improving in central VF locations (mean 1.83±2.3 vs. 0.85±1.2, p=0.014) and peripheral VF locations (4.21±4.6 vs. 2.24±2.6, p= 0.019) was significantly greater in the surgical eyes compared with controls. The number of eyes with improved PSD at FU3 was significantly (p=0.02) greater in the surgical eyes compared with controls (9±5 vs. 3±3).
Conclusions:
Enhancement of central and peripheral visual field sensitivity occurs after surgical reduction of IOP in glaucomatous eyes.
Keywords: 758 visual fields •
568 intraocular pressure