Enhancing access and clinical triage in primary eye care through digital vision testing: validation of the SightConnect mobile application.

Background: Assessment of vision is the vital first step of an eye exam for determining visual status. The availability of portable digital vision testing tools enables vision assessments in remote areas, at home and during teleconsultations. Purpose: To assess the accuracy and agreement for measuring vision using the SightConnect mobile application (SightConnect) compared to in-clinic standard vision testing using the charts and to evaluate the performance of the SightConnect visual acuity grading algorithm, which classifies the visual acuity into one of these categories of visual impairment: mild, moderate and severe. Methods: Individuals visiting LV Prasad Eye Institute as part of their ophthalmic consultation were consecutively recruited for this study. Part -1 of the study evaluated the near visual acuity with SightConnect whereas part-2 evaluated both the distance and near acuity. The standard visual acuity at both distance and near was assessed by trained optometrists and vision technicians. SightConnect further classifies the obtained visual acuity based on severity of the vision and uses them as reference to suggest urgency of referral for an eye exam, as routine, early and urgent need for clinical attention. Results: A total of 1,481 individuals were assessed for visual acuity using SightConnect. Of these 710 participants in part-1 and 771 participants in part-2. Both eyes of the study participants were included in the study. The mean difference in near visual acuity assessment between SightConnect and the clinical measurements was 0.08 logMAR (-4 letters). For distance acuity, the mean difference between SightConnect and clinical measurements was 0.09 logMAR. The intraclass correlation coefficients indicated moderate reliability, with ICCs of 0.74 for near and 0.67 for distance acuity measurements. The visual acuity grading module was 78 to 90% accurate for identifying routine, early and urgent referrals based on vision status. Conclusions: Visual acuity testing using the SightConnect mobile application reported moderate agreement with the standard clinical assessments, and the accuracy in grading visual acuity and suggesting referral urgency was acceptable. These findings support the use of SightConnect applications for enabling and enhancing access to primary eye care services and guiding users on when to seek clinical attention.