Abstract
Purpose :
We have recently shown that smartphone photorefraction achieves a good performance in detecting myopia when compared with autorefraction. Considering that the accuracy of photorefraction is governed by the eccentricity of the flash (distance from flashlight to camera lens), this study aimed to compare the performance of two common smartphone models with different eccentricities.
Methods :
157 participants aged 5 to 42 years were recruited. Only myopic eyes were included (up to -12.70 D, Mean ± SEM: -4.21 ± 0.07 D). As determined by non-cycloplegic open-field autorefraction, participants with low to moderate (>=-6.00 D) and high myopia (<-6.00 D) were screened using two different iPhone models (XS with a lower eccentricity and 13Pro with a higher eccentricity).
Results :
Both iPhone XS and 13Pro yielded reliable refractive error measurements when compared with autorefraction (interclass correlation coefficient of XS: 0.86; 13Pro: 0.87). Both models had high sensitivity and specificity in detecting myopia <-2.00 D according to AAPOS 2021 guideline. XS had a sensitivity/specificity of 94%/76% while 69%/98% was obtained by 13Pro. Area under the ROC curve (AUC) were 0.93 for XS and 0.84 for 13Pro, respectively. When measuring myopia <-6.00 D, 13Pro outperformed by a sensitivity/specificity of 71%/99% as opposed to 49%/99% in XS.
Conclusions :
Consistent with our previous findings, XS yields comparable results to conventional autorefraction in detecting myopia, rendering it a useful screening tool. 13Pro has an increased eccentricity, rendering it more suitable for the precise measurement of high myopia. Smartphones with two camera lenses or more (with different eccentricities) may help boost the performance of smartphone photorefraction.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.