Corneal biomechanical properties in myopic and emmetropic children.

OBJECTIVE: The purpose of this study was to investigate the relationship between corneal biomechanics and ocular morphology in myopic children and adolescents. PATIENTS AND METHODS: The study included 170 right eyes, from 170 patients under the age of 18 years, who underwent a complete ophthalmologic examination, gathering the following data: spherical equivalent (SE) (under pharmacological cycloplegia), biomechanical parameters - corneal hysteresis (CH) and corneal resistance factor (CRF), structural parameters - axial length (AL) and central corneal thickness (CCT). RESULTS: The average age of the patients was 15.26 years old (55.29% girls, 44.70% boys). Out of the 170 eyes, 111 were myopic eyes and 59 were emmetropic. Myopic eyes had a significantly lower CH (p=0.001), CRF (p=0.002) and CCT (p=0.009), and higher AL (p<0.001) than emmetropic eyes. The AL and CCT were significantly higher in myopic males, compared to myopic females (p<0.001 and 0.001). In myopes, we found statistically significant negative correlations between AL and CH (Pearson's r=-0.218), CRF (r=-0.226) and also SE (r=-0.539), and positive between SE and either CH (r=0.193) or CRF (r=0.201). CONCLUSIONS: Corneal biomechanical properties are significantly related to myopia parameters in children.

Assessment of two-year clinical outcomes after keratoconus treatment using two different crosslinking protocols.

OBJECTIVE: This study aims to compare the long-term outcomes of standard corneal collagen crosslinking with accelerated corneal collagen crosslinking (CXL) for progressive keratoconus. PATIENTS AND METHODS: This prospective, comparative study included 79 eyes with progressive keratoconus, which were randomly assigned: 42 eyes received a standard CXL procedure, and 37 eyes were treated with the accelerated CXL protocol. We evaluated the following parameters, before the procedure and 1 month, 6 months, 12 months and 24 months postoperatively: best corrected visual acuity (BCVA), manifest refraction spherical equivalent (MRSE), cylindrical values, corneal dioptric powers on the steepest meridian (Kmax), central corneal thickness (CCT); demarcation line depth (DLD) preoperatively and 1 month after the CXL procedure. RESULTS: The BCVA, MRSE, cylindrical values, Kmax, CCT improved significantly, after both the accelerated and the standard CXL procedure. Throughout the 24-months follow-up, BCVA improvement was achieved sooner in the accelerated group (after 1 month, vs. after 3 months). However, there were no statistically significant differences between the two groups in these aspects. The DLD-to-CCT was significantly greater in the standard group (66% vs. 62%, p = 0.02). CONCLUSIONS: Standard and accelerated CXL are effective in stabilizing keratoconus progression in the long term. In clinical practice, the accelerated protocol has the added benefit of a faster visual recovery, in addition to the known reduced treatment time and increased comfort.