Worse-than-usual visual fields measured in retinitis pigmentosa related to episodically decreased general health. Issue 2 (4th December 2012) - Bittner, Ava Katherine
Abstract : Background/aims: We examined whether retinitis pigmentosa (RP) subjects' worse-than-usual vision measures were related to episodic changes in psychosocial factors and/or general health. Methods: In a prospective, cohort study, 37 RP subjects self-administered personal computer (PC)-based visual acuity (VA), contrast sensitivity (CS) and visual field (VF) tests at home twice a week, for 16 sessions in 2–3 months. Subjects rated their general health prior to each vision test session, and completed the Perceived Stress Scale, Positive and Negative Affect Schedules, and Epworth and Stanford Sleepiness Scales immediately after each session. Results: Nine subjects with reduced mean VA >0.5 log minimal angle of resolution (logMAR) on average had statistically significant 26% more sessions with measured deviations ≥0.1 logMAR from their mean (95% CI 20% to 32%; p<0.001), which were not significantly related to changes in psychosocial factors or general health. Measured deviations ≥0.1 logCS from mean CS were not statistically significantly related to any measured factors. We found a statistically significant increased frequency of sessions with ≥20% VF reduction from the mean (p<0.001) as mean log VF area was reduced. Subjects reporting reduced general health during a session had a statistically significant over twofold greater odds of having a VF reduction from the mean beyond 1 SD (95% CI 1.26 to 5.00; p=0.009). Conclusions: Measured episodic VF reductions were more common in advanced RP and related to decreased general health at a session, which should be considered during clinical examinations and trials when determining true changes in vision. We did not find evidence that fluctuations in psychosocial factors were significantly correlated with vision reductions across subjects.