To compare the effect of corneal rigid and scleral contact lenses (CRCL & SCL) on binocular vision and accommodative function in keratoconus (KCN) patients. In this prospective non- randomized comparative interventional study, patients aged 20 to 40 years with a definitive diagnosis of KCN were participated. Only patients with the best-corrected visual acuity (BCVA) of 0.40 LogMAR or better were included. A comprehensive examination including assessment of BCVA, refractive error, and stereopsis were performed. Furthermore, all participants underwent the complementary binocular vision and accommodation testing. All examinations were performed by spectacle and then repeated after contact lens fitting in both groups. In total, 31 patients were recruited (12 in the CRCL group and 19 in the SCL group). Both groups demonstrated significant improvements in BCVA after lens fitting in both eyes, with the SCL group showing an average gain of approximately 1-3 lines. Additionally, a higher proportion of patients in the SCL group achieved central stereopsis (<100 sec/arc) following lens fitting (p = 0.011). While both SCL and CRCL contributed to improved visual acuity in patients with KCN compared with spectacle, SCL exhibited more advantages over CRCL, particularly in enhancing stereopsis and fusional vergence performance.

This study aimed to evaluate amblyopic participants with myopic anisometropia who, despite not being initially diagnosed with strabismus, failed to improve their visual acuity (VA) after treatment. The hypothesis is that these individuals present with microtropia (MT) and sensory adaptations. Since they appear orthotropic on the unilateral cover test, the hypothesis was tested through an objective evaluation of fixation, the presence of eccentric fixation (EF) would indicate that these eyes are monocularly deviated. Fourteen participants (16.07 ± 10.56 years) were recruited from the Vision Clinic at the University of Murcia. They were myopic, amblyopic, anisometropic, and initially classified as non-strabismic, with no improvement following treatment. They underwent refractive, motor, sensory, eye health and fixation assessments using visuoscopy. A slight tendency towards esophoria was observed at distance (1.07Δ ± 2.67Δ) and near (2.50Δ ± 6.26Δ). Refraction in amblyopic eyes was 3D more myopic than in non-amblyopic eyes, showing a strong correlation (r=0.91, p<0.0001). A non-significant relationship was found between the degree of anisometropia and VA in the amblyopic eye (r = -0.27, p=0.3944), as well as between anisometropia and stereopsis (Spearman rs = 0.22, p=0.439). Of the 14 amblyopic eyes evaluated, 10 presented with EF (indicating strabismus), 2 had unstable fixation, 1 could not be evaluated, and 1 presented central fixation. The majority of the participants evaluated (71.4%) exhibited MT and EF. While this association is well-documented in hyperopic anisometropia, it has not been previously characterized in myopic anisometropia.

To investigate the longitudinal changes in corneal thickness and its contributing factors in primary schoolchildren. This study is a part of the Shahroud Schoolchildren Eye Cohort Study, conducted longitudinally in two phases; in 2015 and then in 2018. Participants were tested for uncorrected visual acuity, best-corrected visual acuity, cycloplegic refraction, biometry, and Scheimpflug corneal imaging. After applying the exclusion criteria, 8782 eyes from 4432 participants were analysed. Of these, 2309 (52.1%) were male. Average three-year changes in central corneal thickness (CCT) and corneal apex thickness were -0.58 (95% CI: -0.94 to -0.22) and -0.59 (95% CI: -0.95 to -0.23) microns, respectively. There was an increase of 8.63 (95% CI: 8.1 to 9.17) microns in the superior corneal thickness after three years while the inferior corneal thickness decreased by an average of -5.75 (95% CI: -6.3 to -5.2) microns. The multiple generalized estimating equation (GEE) model showed that the three-year changes in the CCT were lower in rural than in urban students (β = -1.71; p < 0.001). Moreover, the baseline CCT (β = -0.04; p < 0.001), anterior chamber depth (β = -1.6; p = 0.003), and corneal diameter (β = -1.18; p < 0.001) had a significant inverse association while the body mass index (β = 0.12; p = 0.002) and axial length (β = 0.84; p < 0.001) had a significant direct association with the 3-year changes in CCT. After three years, CCT decreased by advancing age in boys, while remaining almost constant in girls. The 3-year change in CCT was clinically negligible and could indicate its stability in schoolchildren. However, CCT thinning was more remarkable in urban students.