Use of Strabocheck to measure angle of deviation
Reviewed by Fiona Rowe

Strabocheck (SK) is a free to access software and is a measurement of deviation angle based on the corneal light reflex in monocular and binocular photographs uploaded to the website. The purpose of this study was to evaluate SK in comitant horizontal strabismus in children undergoing surgery vs. prism cover test measurements. This was a prospective study with measurements taken one month preoperative, during anaesthesia and postoperative. Forty-four patients were recruited: 17 with infantile esotropia, 14 with exotropia and 13 with partially accommodative esotropia (PET). Mean age was 94 months (range 43–208) and there were 25 males and 19 females. Mean best corrected visual acuity was 0.05 ±0.16logMAR, mean spherical equivalent +2.75 ±2.00D, mean distance angle 26.8 ±12.4PD preop, mean near angle 31.0 ±12.5PD preop, and mean SK 29.7 ±20.7PD. Correlation for SK and prism cover test angle was 0.87 and 0.86 for distance and near. Correlations for exotropia, infantile esotropia and PET were 0.13, 0.77 and 0.77. SK under anaesthesia was 23.4 ±21.1PD for exotropia, 34.5 ±16.9 for infantile esotropia and 37.2 ±15.0 for PET. Mean follow-up was 7.6 ±1.8 months. Postop angles were 12.7 ±7.5PD distance, 13.5 ±9.3PD near and 9.7 ±12.5PD SK. Strong correlations were noted postop for esotropia but not for exotropia. The results indicate a limit of non-dissociative measurements in intermittent exotropia as children can partially or completely compensate their angle whereas prism cover test measurements are dissociative. The authors conclude SK offers another option for angle measurement but with more reliability in esotropia than exotropia. It is important to consider factors that impact on ability to measure the full angle of deviation.

Evaluation of Strabocheck as an objective measurement method of comitant horizontal strabismus in children undergoing surgery.
Azri C, Tomietto P, Marciano E, Bui-Quoc E.
STRABISMUS
2023;31(2):173–81.