To assess the ability of two self-monitoring digital devices to detect metamorphopsia in myopic choroidal neovascularization (mCNV) and compare their usability.
This was a 12-month prospective observational study at a tertiary care eye hospital, Switzerland. Twenty-three Caucasian patients with mCNV were recruited, 21 eyes were analyzed. Primary and secondary outcome measures: Primary outcome measures were the metamorphopsia index scores as assessed by the two self-monitoring digital devices (Alleye App and AMD – A-Metamorphopsia-Detector software) at baseline, at 6 and 12 months and individual optional visits in between. Secondary outcome measures included best corrected visual acuity and morphological parameters (including disease activity) as evaluated by spectral-domain optical coherence tomography and fundus autofluorescence imaging. Location of mCNV was graded using the Early Treatment of Diabetic Retinopathy Study grid overlay. A usability questionnaire was administered at 12 months. Bland-Altman plots evaluated the limits of agreement of both devices. Linear regression analysis assessed the correlation between the difference and the average of the two scores.
A total of 202 tests were performed. Disease activity of mCNV was observed at least once in 14 eyes. Both scores concordantly detected metamorphopsia exhibiting a displaced scale of measurement yielding a coefficient of determination of 0.99. Concordance rate for pathological scores was 73.3%. Both scores were not significantly different in active and inactive mCNV. Overall, the usability scores were higher for the Alleye App than the AMD – A-Metamorphopsia-Detector software (4.61±0.56 vs 3.31±1.20; p<0.001). In subjects aged >75 years, scores were slightly lower (4.08±0.86 vs 2.97±1.16; p= 0.032).