Prevalence and Features of CPR-Type Diplopia in Epiretinal Membrane
By Lynda Seminara
Selected By: Neil M. Bressler, MD, and Deputy Editors
Journal Highlights
JAMA Ophthalmology, December 2017
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Veverka et al. sought to determine the prevalence of central-peripheral rivalry (CPR)–type diplopia among patients with epiretinal membrane (ERM) and to describe the common clinical features. They found that CPR-type diplopia is not uncommon in patients with ERM and is linked to greater severity of metamorphopsia.
This study included 31 adults with ERM treated at clinics specializing in retinal disease in addition to a retrospective cohort of 25 adults with ERM treated at strabismus clinics. Diplopia was established by patient history and responses to questionnaires. CPR type was defined as diplopia associated with evidence of retinal misregistration in the absence of other causes of diplopia. Visual acuity (VA) and ocular alignment findings were documented. Metamorphopsia was assessed qualitatively and quantitatively. Aniseikonia was determined by subjective description and the Awaya new aniseikonia test. Testing for retinal misregistration also was performed. Clinical findings of patients with and without CPR-type diplopia were compared to detect differentiating factors.
Among the group of 31 patients, the prevalence of any type of diplopia was 23% (n = 7) and that of CPR-type diplopia was 16% (n = 5). In the entire series of 56 patients, 12 (21%) had CPR-type diplopia, and 37 (66%) had no diplopia. The other 7 had another type of diplopia and were excluded from subsequent analyses.
Relative to patients who did not have CPR-type diplopia, those with the disorder had better VA in their worse eye (mean difference of –0.23; p = .003) and more severe quantitative metamorphopsia (mean M-score difference of 0.6; p = .01). Rates of aniseikonia misregistration were similar for those with and without the disorder.
Although results indicate that patients with CPR-type diplopia generally have better worse-eye acuity and more metamorphopsia than those without the disorder, individual variability is considerable. Coexistence of retinal misregistration and metamorphopsia appears necessary for the development of CPR-type diplopia, but many patients without this diplopia may exhibit those features.
The original article can be found here.