Comparison of Visual, Tomographic, and Biomechanical Outcomes of 360 Degrees Intracorneal Ring Implantation With and Without Corneal Crosslinking for Progressive Keratoconus: A 5-Year Follow-up.

PURPOSE: To evaluate the long-term (5 years) results of 360 degrees intracorneal ring (ICR) implantation with and without corneal crosslinking (CXL) in patients with progressive keratoconus (KCN). METHOD: This historical cohort study was performed on 35 eyes with progressive KCN, which was randomly divided into 2 groups. Fourteen patients were implanted only with ICR, and 21 patients with KCN were treated with ICR plus CXL simultaneously. Uncorrected distance visual acuity (UCDVA), corrected distance visual acuity (CDVA), and refractive components were collected from patients' medical records. The biomechanical properties of patients were measured using the Corvis ST (Oculus, Inc, Weltzar, Germany). Corneal topography and aberrometry parameters were also recorded from the Pentacam HR device (Oculus). RESULTS: Both UCVA and CDVA increased in both groups after ICR implantation; however, this improvement was more significant in the ICR plus CXL group (P = 0.002 and P = 0.001, respectively). The mean improvement of CDVA in patients with ICR implantation with and without CXL was 0.56 ± 0.67 and 0.33 ± 0.61, respectively. A comparison of the long-term postoperative Tomographic and Biomechanical Index between 2 groups showed a better result in the ICR plus CXL group (P = 0.012). Topographic findings of the anterior corneal surface (flat-K, steep-K, mean-K, and astigmatism) after surgery were significantly better than before surgery in both groups (P < 0.05). CONCLUSIONS: Although ICR implantation alone might halt the KCN progression with acceptable visual, topographic, and biomechanical outcomes, the combination of ICR and CXL has an adjuvant and synergistic effect, especially in long-term follow-up.

Microbiologic Examination of Bandage Contact Lenses Used after Corneal Collagen Cross-linking Treatment.

PURPOSE: To investigate the agents of bacterial contamination of contact lenses after corneal collagen cross-linking (CCL), and to present the possible changes of ocular flora after riboflavin/ultraviolet A. METHODS: Seventy-two contact lenses of patients who underwent CCL and 41 contact lenses of patients who underwent photorefractive keratectomy (PRK) as control group were enrolled to the study. After 48 h of incubation, broth culture media was transferred to plates. Samples were accepted as positive if one or more colony-forming units were shown. RESULTS: There were positive cultures in 12 (16.7%) contact lenses in the CCL group and 5 (12.2%) had positive cultures in PRK group. Coagulase-negative staphlycocci (CNS) were the most frequent microorganism. Alpha hemolytic streptococci and Diphteroid spp. were the other isolated microorganisms. CONCLUSIONS: Bacterial colonization can occur during and early after the CCL procedure in epithelial healing. To prevent corneal infections after the treatment, prophylactic antibiotics should be prescribed.

New clinical pathways for keratoconus.

Pre-2000, the clinical management of keratoconus centred on rigid contact lens fitting when spectacle corrected acuity was no longer adequate, and transplantation where contact lens wear failed. Over the last decade, outcome data have accumulated for new interventions including corneal collagen crosslinking, intracorneal ring implantation, topographic phototherapeutic keratectomy, and phakic intraocular lens implantation. We review the current evidence base for these interventions and their place in new management pathways for keratoconus under two key headings: corneal shape stabilisation and visual rehabilitation.

Outcomes of a new microwave procedure followed by accelerated cross-linking for the treatment of keratoconus: a pilot study.

PURPOSE: To analyze the initial data obtained in a group of patients treated with microwave keratoplasty followed by accelerated corneal collagen cross-linking (CXL) for the correction of keratoconus. METHODS: Prospective, nonrandomized clinical study including six eyes from four patients treated with microwave thermal keratoplasty followed by accelerated CXL. Refractive, topographic, anterior aberrometry, and corneal biomechanics outcomes were analyzed during 6-month follow-up. RESULTS: Immediately after the procedure, a significant reduction of >7.00 diopters (D) was observed in mean keratometry (P=.02). Uncorrected distance visual acuity increased from 0.92±0.52 logMAR (Snellen 20/160) preoperatively to 0.47±0.19 logMAR (Snellen 20/60) postoperatively (P=.05). No statistically significant change was found in corrected distance visual acuity (P=.28). Corneal higher order aberration decreased from 1.89±0.90 to 1.51±0.65 µm and corneal primary coma aberration decreased from 1.45±0.68 µm preoperatively to 0.84±0.23 µm postoperatively (P>.10). No statistically significant changes were found in the biomechanics variables (P=.40). A significant regression of the effect was assessed in keratometry at the end of follow-up (P=.03). CONCLUSIONS: The Keraflex procedure may have the ability to improve refractive status in patients who suffer from keratoconus, as well as induce corneal remodeling to a more anterior regular surface. However, the current treatment regimen is not sufficient to maintain the flattening effect achieved and significant regression occurs.

Crosslinking de colágeno no tratamento do ceratocone / Collagen crosslinking for the treatment of keratoconous

Em meados da década de 90, o crosslinking de colágeno corneano foto-induzido utilizando riboflavina foi proposto como uma nova modalidade terapêutica no tratamento do ceratocone. Desde então foram estudados os efeitos deste procedimento em ambiente laboratorial e posteriormente em ensaios clínicos. Neste artigo, revisamos a literatura que já foi publicada até o momento no intuito de expor sobre o procedimento e seus efeitos.

In middle of 90th decade, corneal collagen crosslinking photo-induced by riboflavin was considered as a new therapeutical modality in the treatment of keratoconus. Since then, the clinical effect of this procedure in laboratorial environment and clinical assays had been studied. In this article, we revise the literature already published until the moment in order to display on the procedure and its effects.

Behaviour modification in the management of chronic habits of abnormal eye rubbing.

OBJECTIVES: To describe how and why many keratoconus patients do not comply with strong advice to control chronic habits of abnormal rubbing. To outline a behaviour modification approach for controlling chronic habits of abnormal rubbing. METHODS: Common reasons for chronic habits of abnormal rubbing have been reviewed as a basis for specifying a behavioural modification approach to habit reversal. RESULTS: The methods described are organized into the classic behavioural modification structure of: (1) habit awareness, (2) competing responses, (3) development of motivation, and (4) social support. This structure is supported by the application of social influence principles to achieve optimum compliance. CONCLUSIONS: The use of take-home written information in the form of an Abnormal Rubbing Guide is the basis for the development of motivation. Family social support is based upon a widening of the responsibility for avoiding eye rubbing to all family members. Some patients will need minimal application of these principles with patient education being sufficient intervention to achieve habit reversal. For patients with strong provocation to rubbing and/or by having a well established rubbing habit, a greater exposure to the habit reversal program described is indicated. Successful habit reversal may slow the rate of ectasia progression. Prophylactic application of the methods described for patients who are at risk for developing keratoconus, or post-laser assisted in situ keratomileusis keratectasia, may show that some forms of keratectasia are preventable.