Altered Ocular Surface Temperature in Congenital Aniridia with PAX6 Pathogenic Variants: Impact of Age, Salzmann Nodules and Ocular Surgery

<i>PAX6</i> haploinsufficiency-related congenital aniridia is frequently associated with ocular surface disease, including meibomian gland dysfunction (MGD), dry eye, limbal stem cell deficiency (LSCD), aniridia-associated keratopathy (AAK), and inflammation. This study measured ocular surface temperature (OST) at the corneal center and four paracentral points (2 mm from center) in patients with congenital aniridia and examined factors influencing OST. Forty-five eyes from 26 aniridia patients (55.6% female; 26.29 ± 17.78 years) with <i>PAX6</i> pathogenic variants and 47 eyes from 25 controls (68.1% female; 24.81 ± 4.73 years; <i>p</i> = 0.1639) were included. Body temperature, OSDI, and OST (TG-1000) were recorded; clinical assessment evaluated MGD, LSCD, AAK, iris malformation, epithelial defects, Salzmann nodules, glaucoma and previous ocular surgery. Body temperature and OSDI did not differ in aniridia and controls (<i>p</i> ≥ 0.606). LSCD was mainly Grade 2 (46.7%) or Grade 4 (40.0%), and AAK Grade 1 (33.3%) or Grade 2 (31.1%). MGD affected 51.1%, Salzmann nodules 22.2%, epithelial defects 2.2%, glaucoma 60.0%, and previous ocular surgery 35.5%. Superior OST was higher in aniridia (34.98 ± 0.55 °C vs. 34.75 ± 0.47 °C; <i>p</i> = 0.012). Exploratory univariate analyses identified that higher AAK grade correlated with lower inferior OST (<i>p</i> = 0.030), iris malformation with reduced central/paracentral OST (<i>p</i> ≤ 0.029), and Salzmann nodules with lower OST overall (<i>p</i> ≤ 0.011). However, in a multivariate model, age, Salzmann nodular degeneration, and prior ocular surgery emerged as key determinants of OST. OST may serve as a noninvasive biomarker in congenital aniridia.