Associations of optical coherence tomography with disability and brain MRI volumetry in patients with multiple sclerosis.

AIM OF THE STUDY: To investigate in a cross-sectional study the correlations of optical coherence tomography (OCT) with clinical and magnetic resonance imaging (MRI) parameters in multiple sclerosis (MS) patients. MATERIAL AND METHODS: OCT parameters include the peripapillary retinal nerve fibre layer (pRNFL) and ganglion cell complex (GCC). Brain magnetic resonance volumetry (T2- and T1- lesions volume, whole brain volume and grey matter volume) was evaluated using the Icobrain program. Clinical data was compared according to the history of optic neuritis (HON). Correlations were determined between OCT parameters and demographic (age, gender), clinical (disease duration, Expanded Disability Status Scale score [EDSS]), and MRI data. RESULTS: Out of 83 recruited people with MS, 27 had HON. The mean age of 75 patients with non-ON eyes was 42.08 ± 10.36 years, and 70.67% of the sample were females. Significant correlations were found between pRNFL and disability, along with several brain MRI-volumetry variables (Fluid-attenuated Inversion Recovery lesions volume [FLAIR]; T1-hypointense lesions volume; T1-lesions volume change; T1-volume lesions enlarging; whole brain volume; whole brain volume normative percentile; and volume of periventricular lesions). Multivariable linear regression analysis showed that age, pRNFL and GCC were significantly associated with T1-hypointense lesions volume change (the model explained 24% of the overall variance of the dependent variable). CONCLUSIONS: The pRFNL value correlates with disability and brain MRI-volumetric parameters in MS patients, serving as a useful neurodegeneration and inflammation surrogate marker.

Changes in central corneal thickness after laser in situ keratomileusis and photorefractive keratectomy.

PURPOSE: To evaluate changes in corneal thickness after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in eyes with the same preoperative refraction, correlate these changes to postoperative refractive outcomes, and compare corneal healing process in a standardized subset of patients. METHODS: Central corneal thickness was measured by contact ultrasound pachymetry in 14 eyes of 8 patients with preoperative myopia of -6.00 D who had LASIK, and in 14 eyes of 8 patients with the same preoperative refractive error who had PRK. Measurements were taken preoperatively, and 1 week, 3, and 6 months after surgery. Data were evaluated and compared using the paired Student t-test and Pearson correlation coefficient. RESULTS: Mean preoperative central corneal thickness in the LASIK group was 549.14 +/- 37.4 microm, and in the PRK group, 552.64 +/- 34.9 microm. At 1-week postoperatively, mean central corneal thickness in the LASIK eyes was 467.28 +/- 29 microm and in the PRK eyes, 473.85 +/- 39.2 microm; at 6 months, central corneal thickness had increased in both groups compared to the 1-week values; LASIK eyes had a mean central corneal thickness of 481.42 +/- 23.0 microm and PRK, 481.50 +/- 35.3 microm. Mean postoperative refraction after 6 months was -0.48 +/- 0.30 D in the LASIK group and -0.67 +/- 0.35 D in the PRK group. CONCLUSION: Increase in central corneal thickness between 1 week and 6 months postoperatively occurred in both LASIK and PRK eyes, but differences were not statistically significant. No statistically significant differences were found in myopic regression between the two patient groups.