CAI-augmented macular pigment supplementation improves visual acuity and contrast sensitivity in eyes with pericentral glaucomatous visual field loss

Abstract

Purpose : The retinal pigment epithelium (RPE) is a selective barrier for nutrients and waste within the retina. The RPE contains carotenoids and xanthophylls that dissipate energy from oxidative species. Lumega-Z (CT) is a commercial medical food containing several pre-foveolar membrane carotenoids in a microliposomal emulsion. Dorzolamide is a topical carbonic anhydrase inhibitor (CAI) with the capacity to enhance perifoveolar perfusion, and may thereby enhance the delivery of macular pigment-containing oral supplements. This prospective randomized double-masked placebo-controlled study examines the effects of combined CT/topical CAI on VA and 12cpd CS, a spatial frequency strongly associated with glaucoma progression.

Methods : We used methods described in “Augmented Macular Pigment Supplement and Pericentral Visual Function: A Randomized Controlled Trial” (NCT04676126). Pearson correlation was used for statistical analysis of treatment and Fisher’s r to z transformation was used to compare the groups.

Results : Mean values from paired-eye data (n=23:10T/13P) were evaluated over 3 mo. VA: Both groups improved significantly, the treatment group (TG) showed greater improvements than the placebo group (PG). A comparison of correlations showed a significant difference, p = 0.03, indicating that treatment was significantly associated with improved LogMar acuity (placebo: -0.01x + 0.1, R² 0.4; treatment: -0.02x + 0.2, R² 0.8). 12cpd CS: Both groups showed significant improvement in ability to discern contrast patterns, the TG with a greater and more consistent (p<.0001) increase than the PG (placebo: 0.1x + 2.4, R² 0.2; treatment: 0.5x + 0.4, R² 0.9).

Conclusions : Co-administration of topical CAI/oral CT was associated with a significant positive impact on 12cpd CS and VA from pre-treatment baseline levels relative to placebo-treated eyes. Patients in this study were selected for progressive glaucomatous VF progression despite stable IOP control. The statistically inferior, yet significant, improvement in pericentral VF observed among PG eyes was likely attributable to regression-to-the-mean or learning effect. The improvements in VA and 12cpd CS in the TG were significantly greater than those observed among the PG. These findings illustrate the importance of placebo-control prospective studies in discerning therapeutic efficacy from predictable artifacts.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.