Correlation between Central Visual Field Defects and Stereopsis in Patients with Early-to-Moderate Visual Field Loss

Abstract

Purpose: To investigate the association between stereoacuity and the presence of central visual field defects (CVFDs) due to glaucoma.

Design: A prospective, cross-sectional cohort study.

Participants: Participants with early-to-moderate glaucoma with a visual acuity better than 20/40, less than a 2-line difference in visual acuity between eyes, and 2 reliable Humphrey visual fields (VFs) (24-2 SITA standard) with mean deviation (MD) in the worse eye better than - 12 dB.

Methods: Stereoacuity was measured using the Titmus stereo test. Participants with a significant field defect (P < 0.005) in any 1 of the central 4 points in the 24-2 SITA standard total deviation map in either eye were classified as having a CVFD. Vision-related quality of life (VR-QOL) was measured using 25-item National Eye Institute Visual Function Questionnaire scores. Logistic regression was used to determine the associations between the level of stereoacuity and age, sex, race, glaucoma type, presence of CVFDs, visual acuity, contrast sensitivity, and VF MD.

Main outcome measures: Stereoacuity in the CVFD and non-CVFD groups.

Results: Sixty-five participants met the inclusion criteria. The mean age of the participants was 64.3 ± 8.0 years, and 64.6% were women. The median stereoacuity was 60 arc seconds (interquartile range [IQR], 40-120 arc seconds). Forty-two (65%) patients had CVFDs, and 23 (35%) patients did not. The median stereoacuity of the CVFD group was worse than that of the non-CVFD group (60 arc seconds [IQR, 50-140 arc seconds] vs. 40 arc seconds [IQR, 40-80 arc seconds], respectively; P = 0.001). The non-CVFD group had a higher percentage of participants with normal stereopsis than the non-CVFD group (61% vs. 21%, respectively; P = 0.001). A multivariable analysis found that the presence of CVFDs was associated with worse stereopsis levels (odds ratio, 4.49; P = 0.021). The CVFD group had a lower Visual Functioning Questionnaire-25 (VFQ-25) composite score (84.0 vs. 91.4; P = 0.004) and lower VFQ-25 subscale scores for general vision, near activities, and mental health (P < 0.05).

Conclusions: Central visual field defects were associated with increased odds of poor stereoacuity in patients with early-to-moderate glaucomatous VF loss. Specifically, patients without CVFDs are more likely to have normal stereopsis and higher VR-QOL than those with CVFDs. Patients with CVFDs should be counseled regarding how depth perception difficulties may affect daily living.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Central visual field loss; Glaucoma; Quality of life; Stereoacuity; Stereopsis; Visual field.