Purpose
Research suggests that early detection and treatment of choroidal neovascularization (CNV) in age related macular degeneration (AMD) preserves visual acuity and improves prognosis. Therefore it is important for patients to monitor their eyesight at home and be alerted when they may need to visit their ophthalmologist. The purpose of this study is to evaluate the Hyperacuity Exam (HAC), an interactive adaptation of the Amsler Grid on the iPad, to assess its ability to identify CNV in patients using a cross-sectional observational study.
Methods
After recruiting and obtaining consent from patients with AMD, patients were tested for best corrected visual acuity, received Optical Coherence Tomography (OCT) imaging, and a routine ophthalmic examination. Patients were then taught how to use the HAC and given time to practice. The patients were asked to use the HAC one eye at a time. With optimized app calculations performed on a prior set of patients, the scores were analyzed to determine whether the patient was likely to have active CNV. A masked retinal specialist then evaluated the OCT from the day of the HAC exam to determine whether the patient had current CNV.
Results
The researcher recruited 22 patients with AMD from a single center, excluding patients over 90 and under 65. Two patients were excluded due to a demonstrated inability to use the iPad. Six patients were excluded due to disease in the macula other than CNV. Of the remaining 14 patients, five eyes were excluded due to geographic atrophy, pigment, or scarring in the macula. Of the 23 eyes, 13 eyes had nonexudative macular degeneration as determined by the masked retinal specialist. Seven eyes had exudative macular degeneration with no current CNV, and five eyes had exudative macular degeneration with current CNV. The sensitivity to detect current CNV by the HAC was 83% (CI: 53% - 100%) while the specificity was 85% (CI: 70% - 100%).
Conclusions
The HAC may detect active exudative AMD with a relatively high specificity and decent sensitivity. The data suggest that the HAC can help to evaluate whether patients have CNV and should see their ophthalmologist. Due to the small sample of patients with current CNV, future research should be conducted to confirm the results. Longitudinal studies may be especially useful in assessing whether a learning curve on the HAC will impact the results.