Smartphone in place of Hertel exophthalmometer for measuring exophthalmos

Of 39 participants, 23 patients (median [IQR] age, 54 [44-59] years; 15 [65%] female and 8 [35%] male) showed a mean difference in eyeball protrusion of 3.3 mm and 16 healthy volunteers (median [IQR] age, 32 [30-37] years; 11 [69%] female and 5 [31%] male) of 0.8 mm without any significant difference between the 3 methods. Accuracy and precision agreement between exophthalmos measures with the smartphone and the Hertel exophthalmometer showed an intraclass correlation coefficient (ICC) of 0.89 (95% CI, 0.80-0.94) and 0.93 (95% CI, 0.83-0.97) for the high-resolution scanner. Interoperator agreement was highest for the high-resolution scanner (ICC, 0.99 [95% CI, 0.98-0.99]), followed by the smartphone (ICC, 0.95 [95% CI, 0.92-0.97]) and the Hertel exophthalmometer (ICC, 0.91 [95% CI, 0.85-0.95]). Test retest reliability was similarly high for the smartphone (ICC, 0.93 [95% CI, 0.82-0.95]), the Hertel exophthalmometer (ICC, 0.92 [95% CI, 0.83-0.96]), and the high-resolution scanner (ICC, 0.95 [95% CI, 0.89-0.97]).

The findings of this study demonstrate relatively high accuracy and precision, interoperator reliability, and test-retest reliability for smartphone exophthalmometry. These data support the use of a smartphone in place of a Hertel exophthalmometer for measuring exophthalmos in the future.

Source: Popov T, Fierz FC, Bockisch CJ, Weber KP. Using Smartphone Exophthalmometry to Measure Eyeball Protrusion. JAMA Ophthalmol. Published online September 21, 2023. doi:10.1001/jamaophthalmol.2023.4044