Early Epithelial Remodeling After Standard and Iontophoresis-Assisted Corneal Cross-linking as Evaluated by Spectral-Domain Optical Coherence Tomography.

PURPOSE: To evaluate and compare epithelial remodeling after standard corneal cross-linking (S-CXL) and iontophoresis-assisted CXL (I-CXL) in eyes with keratoconus by anterior segment optical coherence tomography (AS-OCT). METHODS: In this prospective, observational study, AS-OCT and corneal topography were performed before and 1, 3, and 6 months after surgery. Corneal pachymetry was performed and epithelial and stromal thicknesses (central and 16 points on the 6-mm central zone) and the maximum simulated keratometry value (Kmax) were measured. RESULTS: Two groups of 30 patients (60 eyes total) with progressive keratoconus underwent S-CXL or I-CXL. Before surgery, both groups of patients presented with an irregular epithelial thickness profile. At 6 months postoperatively, localized corneal epithelial thinning was observed in the superior (P = .026), inferior (P = .034), inferonasal (P = .024), and nasal (P = .035) areas at 3 mm and in the superior (P = .039), nasal (P = .043), and inferior (P = .01) areas at 6 mm in the SCXL group. Localized corneal epithelial thinning was observed at 3 (P = .04) and 6 (P = .01) mm in the inferior area in the I-CXL group. No significant stromal changes were observed for either group. Kmax was stable in both groups at 6 months. CONCLUSIONS: Significant epithelial remodeling occurs after S-CXL, resulting in a thinner, more regular thickness profile than after I-CXL. Epithelial thickness profile measurements after I-CXL could be used as an adjunctive follow-up tool for monitoring the efficacy of CXL in progressive keratoconus. [J Refract Surg. 2018;34(8):551-558.].

Conventional and Iontophoresis Corneal Cross-Linking for Keratoconus: Efficacy and Assessment by Optical Coherence Tomography and Confocal Microscopy.

PURPOSE: To compare the efficacy, safety, and microstructural corneal changes during 2 years after conventional corneal collagen cross-linking (C-CXL) and transepithelial corneal CXL by iontophoresis (I-CXL) for keratoconus. METHODS: Eighty eyes of 80 patients with progressive keratoconus were treated by C-CXL (n = 40) or I-CXL (n = 40). Patients were investigated before surgery and 1, 3, 6, 12, and 24 months after treatment. We measured central corneal thickness and maximal simulated keratometry values (Kmax) and performed specular microscopy and in vivo confocal microscopy at each time point. The demarcation line was assessed 1 month after treatment. RESULTS: Kmax remained stable after I-CXL during the entire study period (P = 0.56), whereas the average keratometry increased by 0.2 diopter (50.9 ± 5.6-51.1 ± 5.2). Kmax significantly decreased 1 (P = 0.02) to 2 years (P < 0.01) after C-CXL, with an average decrease of 1.1 diopters (49.9 ± 4.5-48.8 ± 4.2). The failure rate of I-CXL was 20% and that of C-CXL 7.5%. The demarcation line was superficially visible in 35% of cases after I-CXL compared with 95% of cases after C-CXL. Endothelial cell density and central corneal thickness remained stable during the entire study period. The change in Kmax 2 years after C-CXL and I-CXL and the preoperative Kmax were negatively correlated (r = 0.14, P = 0.013, and r = 0.17, P = 0.007, respectively). CONCLUSIONS: I-CXL halted progression of keratoconus less efficiently than did C-CXL after 2 years of follow-up. Longer prospective studies are still needed to ensure I-CXL efficacy.

Multiple Sclerosis-related Uveitis: Does MS Treatment Affect Uveitis Course?

PURPOSE: Few data are available regarding the optimal treatment of multiple sclerosis (MS)-related uveitis. The aim of this study was to describe clinical features of MS-associated uveitis and determine how MS treatment affects the course of uveitis. METHODS: Retrospective, multicenter study. Patients were divided into two groups according to the use (group 2) or not (group 1) of immunomodulatory drugs. Characteristics of uveitis and treatment were reviewed. RESULTS: A total of 68 eyes from 36 patients (17 in group 1 and 19 in group 2) were included. All patients were treated with topical and/or systemic steroids for uveitis. Uveitis occurred 1-17 years prior to neurologic symptoms in 78% of patients. Uveitis was more severe in group 2 (p<0.05), with a tendency toward a higher rate of chronic uveitis (p = 0.06). CONCLUSIONS: MS-related uveitis has often a favorable evolution. Patients on interferon-beta have more severe and chronic uveitis. As far as we are concerned, interferon-beta given on the sole indication of uveitis is not recommended. If steroid-sparing agent is required for intraocular inflammation, immunosuppressive drugs should be considered.

Three Different Protocols of Corneal Collagen Crosslinking in Keratoconus: Conventional, Accelerated and Iontophoresis.

Keratoconus is a bilateral and progressive corneal ectasia. In order to slow down its progression, corneal collagen cross-linking (CXL) has recently been introduced as an efficient treatment option. In biological and chemical sciences, crosslinking refers to new chemical bonds formed between reactive molecules. Hence, the aim of corneal collagen CXL is to synthetically increase the formation of crosslinks between collagen fibrils in the corneal stroma. Despite the fact that the efficiency of the conventional CXL (C-CXL) protocol has already been shown in several clinical studies, it might benefit from improvements in duration of the procedure and removal of corneal epithelium. Hence, in order to provide a coherent evaluation of two new and optimized CXL protocols, we studied keratoconus patients who had undergone one of the three CXL treatments: iontophoresis (I-CXL), accelerated CXL (A-CXL), and conventional CXL (C-CXL). A-CXL is a 6 time faster CXL procedure using a ten time higher UVA irradiance but still including an epithelium removal. Iontophoresis is a transepithelial non-invasive technique in which a small electric current is applied to improve riboflavin penetration throughout the cornea. Using anterior segment optical coherence tomography (AS OCT) and in vivo confocal microscopy (IVCM), we conclude that regarding the depth of treatment penetration, conventional CXL protocol remains the standard for treating progressive keratoconus. Accelerated CXL seems to be a quick, effective and safe alternative to treat thin corneas. The use of iontophoresis is still being investigated and should be considered with greater caution.

Optical coherence tomography and confocal microscopy following three different protocols of corneal collagen-crosslinking in keratoconus.

PURPOSE: We compared the efficacy and early morphological changes in the cornea following conventional (C-CXL), transepithelial by iontophoresis (I-CXL), and accelerated (A-CXL) collagen cross-linking in keratoconus. METHODS: A total of 45 eyes of 45 patients with progressive keratoconus who underwent corneal collagen crosslinking (CXL) was divided into three groups: C-CXL (n = 15), A-CXL (n = 15), and I-CXL (n = 15). Patients were examined before surgery and at 1-, 3-, and 6-month intervals following surgery. Density of corneal sub-basal nerves, anterior and posterior keratocytes, corneal endothelium, demarcation line depth, and maximal simulated keratometry values (Kmax) were all assessed. RESULTS: Compared to preoperative values, the mean corneal sub-basal nerve and anterior stromal keratocyte densities were significantly lower at 6 months in the C-CXL and A-CXL groups (P < 0.001), whereas they returned to preoperative values in the I-CXL group (P = 0.083 and P = 0.909, respectively). The corneal demarcation line was visible 1 month after surgery in 93% of cases (mean depth, 302.8 ± 74.6 µm) in the C-CXL group, 87.5% (mean depth, 184. 2 ± 38.9 µm) in the A-CXL group, and 47.7% (mean depth, 212 ± 36.5 µm) in the I-CXL group (P = 0.006). There were no significant differences between confocal microscopy and optical coherence tomography measurements of the corneal demarcation line depth (P > 0.05). The Kmax, corneal central thickness, and BSCVA remained stable during the whole study period. CONCLUSIONS: Iontophoresis was associated with weaker damage of corneal sub-basal nerves and anterior keratocytes compared to conventional procedures, but the demarcation line was present in less than 50% of cases and was more superficial than with the traditional procedure.