Abstract
Purpose: :
Vision function as measured by best-corrected distance visual acuity (VA) in the treated eye is an accepted efficacy endpoint in clinical research. The impact of vision loss on patient visual functioning is often measured in these same trials. Patients report VRQoL based on their daily experiences with binocular vision and changes in vision quality may not always correspond exactly with the VA in the treated eye as it may not be the "better-seeing" eye. We evaluated the effect of treated eye (better or worse seeing) on changes in VRQoL as measured by the National Eye Institute -Visual Functioning Questionnaire 25 (NEI-VFQ).
Methods: :
Data were derived from a multicenter, sham-controlled, double-masked clinical trial of pegaptanib in DME.
Results: :
The overall VA benefit was significantly better (p<0.05) in the treated arm at one year. In 258 subjects where baseline VA in both eyes was available, treatment was administered in the better-seeing eye in 66. VRQoL in pegaptanib subjects treated in the better-seeing eye showed statistically significant (p<0.05) and clinically meaningful difference (> 5 points) at Week 54 over sham in the following domains of the NEI-VFQ: composite score, distance vision, functional (role and social), and peripheral vision. In an ANCOVA model, the interaction of ‘treatment’ and ‘eye’ was significant (p<0.05) supporting that VRQoL outcomes are not necessarily independent of the relative VA of the fellow eye.
Conclusions: :
When evaluating the efficacy of treatment, changes in VA in the treated eye is relevant. However, in measuring clinical effectiveness and patient benefit, it is important to recognize that functioning can be dependent on the relative VA status of the eye selected for treatment.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00605280
Keywords: visual acuity • quality of life • diabetic retinopathy