Relationship between Vision-related Activity Limitations and Binocular Visual Field Patterns in Retinitis Pigmentosa

Abstract

Purpose : Retinitis pigmentosa (RP) has characteristic patterns of visual field (VF) loss and is known to reduce perceived quality of life (QoL: activity limitations). There have been no systematic evaluations of the relationship between VF patterns and QoL. Of particular interest was the impact of peripheral islands of vision which are lost as RP progresses.

Methods : VFs were measured out to 60-degrees wide with the Humphrey Field Analyzer. Archetypal analysis was used to decompose reliable binocular VFs, finding representative features within the data. Rasch analysis was applied to 12 items of the Vision Function Scale (VFS: Pesudovs et al., 2010) plus an additional 3 driving items, all from the National Eye Institute Visual Function Questionnaire. Data from both sources was available for 604 exams of 194 subjects (20 to 60 years) for up to 7 visits and 6 years of follow-up. A generalized structural equation model examined the relationship between the QoL (VFS-plus scale) and the binocular VF archetype coefficients.

Results : As expected, QoL decreased with increasing age. In the final model, found using a backwards stepwise approach, 4 of the 10 archetypes were independently associated with QoL. Those archetypes were (1) full field; (2) superior scotoma; (3) small central plus large temporal island; and (4) peripheral scotoma beyond 30-degrees. QoL improved with higher coefficients (i.e. archetype was better descriptor of measured VF) of all four archetypes. Interestingly, the three “tunnel vision” archetypes were not included in the final model, despite being univariate correlated with QoL. Those three archetypes were also strongly negatively correlated with three of the archetypes that remained in the model.

Conclusions : This is the first demonstration of a relationship between QoL and specific VF patterns. Lateral peripheral islands of residual vision were associated with better QoL. This is the first evidence that peripheral islands in the VF provide benefit in conducting daily activities.

This is a 2020 ARVO Annual Meeting abstract.