Purpose The disc‐fovea angle (DFA) is used as a relevant indicator of ocular torsion change in cyclovertical strabismus. However, interpretation of the variation in time must differentiate whether a real change has occurred or if the disparity is due to random measurement error. The aim of the study was to obtain the minimal detectable change (MDC) of the DFA. It represents the minimal variation between two measurements that may be considered a real ocular torsion change. Methods A prospective cross‐sectional study was conducted in San Carlos Clinical Hospital of Madrid, Spain. Sixty healthy right eyes from 60 patients (31 men and 29 women) were recruited. Three digital fundus photographs were obtained, and between measurements, the patient moved their head away from the head support and then returned. Two observers quantified the DFA with software designed with MATLAB. Test‐retest and interrater reliability were calculated. Results Mean participant age was 56.1 years (SD 16.6, range 25–85). Mean DFA was 8.1° (SD 3.5, range 1.3–18.5). Test‐retest reliability for Observer 1 (Ob1), Observer 2 (Ob2) and interrater reliability were excellent (ICC 0.80, 0.83 and 0.95, respectively). Precision was 2.9° (Ob1) and 3.0° (Ob2), and the MDC95 was 4.1° (Ob1) and 4.2° (Ob2). Bland‐Altman analysis revealed an absence of bias and a homoscedastic distribution of the differences. Conclusions The MDC of the DFA in fundus photography was 4°, which represents the minimal change that may be considered a real change in ocular torsion. This result may improve the interpretation of ocular torsion changes in surgery and clinical scenarios.

IntroductionWhile optical coherence tomography (OCT) measurements of the lower tear meniscus height (LTMH) have been reported in adults, here we obtained LTMH measurements through Fourier Domain OCT in healthy children and compared these with values obtained in healthy adults.MethodsParticipants were children 7–17 years of age and a control group of adults 20–40 years of age. Inclusion criteria were no abnormal eye conditions or the use of contact lenses. Candidates who fulfilled the TFOS DEWS II criteria for dry eye disease (DED) were excluded. All subjects underwent LTMH measurement (OCT Spectralis) and tests for non‐invasive tear break‐up time and ocular surface staining. Participants also completed the ocular surface disease index questionnaire.ResultsA total of 86 children and 27 adults were included. Mean LTMH values in the children and adult groups were 217.40 ± 71.40 μm and 225.0 ± 54.86 μm, respectively; p = 0.53. However, 59.3% of the children had an LTMH ≤210 μm suggestive of DED, compared with only 33.3% of adults (p = 0.02). For the children, no significant differences in LTMH were observed with sex or for those more or less than 12 years of age.ConclusionsOptical coherence tomography‐derived LTMH measurements were obtained in healthy children. While values were similar in children and adults, a greater proportion of children had an LTMH compatible with a diagnosis of DED. More studies in different paediatric populations are required to establish a complete set of normative LTMH measurements.

Contact lenses were fitted according to her corneal topography. Gas permeable contact lenses were chosen as first choice and with proper fitting and vigilant follow-up they may be worn safely on a daily basis.