Zisis Gatzioufas

Collagen Cross-Linking with Photoactivated Riboflavin (PACK-CXL) for the Treatment of Advanced Infectious Keratitis with Corneal Melting

PURPOSE To investigate the efficacy and safety of corneal collagen cross-linking (CXL) with photoactivated riboflavin (photoactivated chromophore for infectious keratitis [PACK]-CXL) in the management of infectious keratitis with corneal melting. DESIGN Prospective clinical trial. PARTICIPANTS Forty eyes from 40 patients with advanced infectious keratitis and coexisting corneal melting. METHODS Twenty-one patients (21 eyes) underwent PACK-CXL treatment in addition to antimicrobial therapy. The control group consisted of 19 patients (19 eyes) who received only antimicrobial therapy. MAIN OUTCOME MEASURES The slit-lamp characteristics of the corneal ulceration, corrected distance visual acuity, duration until healing, and complications were documented in each group. The Mann-Whitney U test was used for statistical analysis. P values less than 0.05 were considered statistically significant. RESULTS The average time until healing was 39.76 ± 18.22 days in the PACK-CXL group and 46.05 ± 27.44 days in the control group (P = 0.68). After treatment and healing, corrected distance visual acuity was 1.64 ± 0.62 in the PACK-CXL group and 1.67 ± 0.48 in the control group (P = 0.68). The corneal ulcerations width and length was significantly bigger in the PACK-CXL group (P = 0.004 and P = 0.007). Three patients in the control group demonstrated corneal perforation; infection recurred in 1 of them. No serious complications occurred in the PACK-CXL group. CONCLUSIONS Corneal CXL with photoactivated riboflavin did not shorten the time to corneal healing; however, the complication rate was 21% in the control group, whereas there was no incidence of corneal perforation or recurrence of the infection in the PACK-CXL group. These results indicate that PACK-CXL may be an effective adjuvant therapy in the management of severe infectious keratitis associated with corneal melting.

Safety profile of high-fluence corneal collagen cross-linking for progressive keratoconus: preliminary results from a prospective cohort study.

PURPOSE To investigate the effect of high-fluence corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A in the management of progressive keratoconus. METHODS Preliminary results from a prospective cohort study. Seven eyes from 7 patients with progressive keratoconus subjected to CXL were included. CXL was performed as a standard epithelium-off procedure, irradiating with high-fluence settings (18 mW/cm(2) for 5 minutes). Endothelial cell density (ECD), speed of postoperative epithelial healing, maximal and average keratometric readings (Kmax and Kmean, respectively) of the anterior corneal surface, and corrected distance visual acuity (CDVA) were evaluated preoperatively and at 1 and 6 months after CXL. One-way analysis of variance was applied for statistical analysis. P values less than .05 were considered significant. RESULTS ECD did not change significantly postoperatively and complete epithelial healing occurred in all eyes within 96 hours postoperatively. No morphological alterations in the corneal limbus were observed. Kmax, Kmean, and CDVA showed no significant changes at 1 and 6 months postoperatively. No complications were observed postoperatively. CONCLUSIONS Although the preliminary results are not sufficient for a valid evaluation of the biomechanical effect and the overall safety profile of high-fluence CXL in vivo, they demonstrate that CXL at 18 mW/cm(2) for 5 minutes affects neither endothelial cell density nor the speed of epithelial healing, an indirect indicator of limbal stem cell function.

Biomechanical profile of the cornea in primary congenital glaucoma

Purpose:  The aim of our study was to investigate the biomechanical properties of the cornea in primary congenital glaucoma (PCG) and to identify the potential ocular determinants, which affect the corneal biomechanical metrics.

Biomechanical diagnosis of keratoconus: evaluation of the keratoconus match index and the keratoconus match probability

Purpose:   To evaluate the diagnostic capacity of the Ocular Response Analyser’s keratoconus match index (KMI) and keratoconus match probability (KMP) classification in a sample of keratoconus (KC) patients.

Impact of Fluorescein on the Antimicrobial Efficacy of Photoactivated Riboflavin in Corneal Collagen Cross-linking

PURPOSE To investigate the effect of fluorescein on the antimicrobial efficacy of photoactivated riboflavin in corneal collagen cross-linking (CXL) in vitro. METHODS The ultraviolet light-A (UVA) absorption by fluorescein and riboflavin in different concentrations was analyzed with a spectrophotometer. The killing rate of Staphylococcus aureus strains after CXL with UV-A irradiation using different solutions containing riboflavin and/or fluorescein, was evaluated in vitro. RESULTS Fluorescein absorbed UV-A to a significant extent, which augmented with increasing concentration. Moreover, addition of fluorescein to the riboflavin solution contributed to a significant reduction of the killing rate of S. aureus strains after 30 minutes of UV-A irradiation in vitro with a killing rate of 85%, whereas it was 47% in the presence of 2% fluorescein (P = .0247). CONCLUSIONS The results indicate that fluorescein competes with riboflavin for the absorption of UV-A during CXL and reduces the antimicrobial effect of the procedure. The authors recommend that physicians treating infectious ulcerative keratitis by CXL should not stain the cornea with fluorescein for visualization of the corneal ulceration prior to CXL

Effect of ranibizumab on serous and vascular pigment epithelial detachments associated with exudative age-related macular degeneration.

Purpose To report the effect of intravitreal ranibizumab therapy for serous and vascular pigment epithelial detachments (PED) associated with choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD). Methods In a prospective study, best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) data were collected for 62 eyes of 62 patients, with serous or vascular PED associated with CNV secondary to AMD. Intravitreal ranibizumab 0.5 mg was administered with a loading phase of three consecutive monthly injections, followed by monthly review with further treatment, as indicated according to the retreatment criteria of the PrONTO study. The change in visual acuity and PED height from baseline to month 12 after the first injection was determined. Results Sixty-one eyes of 61 patients (one of the patients developed retinal pigment epithelial tear and was excluded from the study) were assessed at the 12-month follow-up examination. There were two types of PED, including vascular PED in 32 patients (Group A) and serous PED (Group B) in 29 patients. The mean improvement of mean BCVA from baseline to 12 months was 0.09 logMAR (Logarithm of the Minimum Angle of Resolution) in Group A and 0.13 logMAR in Group B. Both groups showed significant improvement of the mean BCVA 12 months after the first injection compared with the baseline value (P < 0.05). In relation to the PED height, the mean decrease of mean PED height from baseline to 12 months was 135 μm in Group A and 180 μm in Group B. Both groups showed significant reduction of the PED height during the follow-up period (P < 0.01). The PED anatomical response to ranibizumab was not correlated with the BCVA improvement in any of the groups. Apart from one patient who developed pigment epithelial tear no other complications were documented. Conclusion Ranibizumab is an effective and safe treatment for improving vision in patients with serous and vascular PED, although the anatomical response of the PED to ranibizumab may not correlate directly with the visual outcome.

Diagnostic capacity of the keratoconus match index and keratoconus match probability in subclinical keratoconus

Purpose To evaluate the diagnostic capacity of the Ocular Response Analyzer’s keratoconus match index (KMI) and keratoconus match probability (KMP) classification in keratoconus‐suspect eyes. Setting Department of Ophthalmology, University Clinics Saarland, Homburg, Germany. Design Comparative case series. Methods The KMI and KMP parameters in keratoconus‐suspect eyes and normal eyes (control group) were compared. The quantitative keratoconus percentage index was calculated for all suspect eyes. According to the thinnest corneal thickness (TCT), keratoconus‐suspect eyes were divided into 2 subgroups: subgroup 1 (TCT <520 &mgr;m) and subgroup 2 (TCT >520 &mgr;m). The KMI’s overall predictive accuracy was assessed using receiver operating characteristic (ROC) curves. The relationship between KMI and a series of Scheimpflug‐derived keratoconus‐related indices was evaluated using Spearman analysis. Results The mean KMI was 0.41 ± 0.29 (SD) in the keratoconus‐suspect group (50 eyes) and 0.94 ± 0.29 in the control group (50 eyes) (P<.001). Nonsignificant KMI differences were detected between the keratoconus‐suspect subgroups (subgroup 1, 27 eyes; subgroup 2, 23 eyes) (P=.059). Nonsignificant correlations were found between Scheimpflug indices and the KMI. The KMP identified 27.65% of control eyes as keratoconus suspect and 10.71%, 28.57%, and 3.57% of keratoconus‐suspect eyes as being normal, having mild keratoconus, or having moderate keratoconus, respectively. The ROC analysis for the KMI indicated a predictive accuracy of 94% (cutoff point 0.72). Conclusions The KMI seems to be a valuable index in the early diagnosis of keratoconus‐suspect eyes. The KMP identified a significant percentage of topographically defined keratoconus‐suspect eyes as normal or keratoconic. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Transepithelial Corneal Cross-linking Using an Enhanced Riboflavin Solution.

PURPOSE To assess the efficacy of a modified high concentration riboflavin solution containing benzalkonium chloride 0.01% for transepithelial corneal cross-linking (CXL). METHODS In this prospective, interventional multicenter cohort study, 26 eyes of 26 patients with documented progressive keratoconus who underwent transepithelial CXL were included. Follow-up at 6 and 12 months postoperatively included slit-lamp examination, uncorrected and corrected distance visual acuity (logMAR), maximum keratometry (Kmax), and corneal pachymetry (corneal thinnest point) as determined by Scheimpflug imaging. Statistical analysis was performed using repeated measures analysis of variance and the Friedman test for parametric and non-parametric data, respectively. P values less than .05 were considered significant. RESULTS Kmax did not change significantly at postoperative months 6 and 12. Changes in corneal thinnest point did not change postoperatively over 12 months. Uncorrected and corrected distance visual acuity did not change postoperatively. Progression (defined by an increase in Kmax greater than 1.00 diopter occurred in 46% of eyes at 12 months. Corneal epithelial defects were observed in 46% of the patients and marked punctate corneal epitheliopathy/loose epithelium in 23% of the patients in the immediate postoperative period. No corneal infection, sterile infiltrates, or haze were observed. CONCLUSIONS Transepithelial CXL with an enhanced riboflavin solution did not effectively halt progression of keratoconus. Significant epithelium damage was evident in the immediate postoperative period. [J Refract Surg. 2016;32(6):372-377.].

First experience with the new high-frequency femtosecond laser system (LDV Z8) for cataract surgery

Background The purpose of this work is to report our experience using the new Z8 laser system for femtosecond laser-assisted cataract surgery (FLACS) and to provide a sample of the performance and safety results using this new technology. Methods This prospective observational study was performed at the Swiss Eye Research Foundation, Eye Clinic ORASIS, Reinach, Switzerland. Fourteen patients were subjected to unilateral FLACS. Capsulotomy and lens fragmentation were performed with the aid of the LDV Z8 femtosecond laser system. Ease of phacoemulsification (on a 4-point scale), completeness of capsulotomy (on a 10-point scale), time for preparation of femtosecond laser (minutes), effective phacoemulsification time (seconds), total duration of surgery (minutes), and safety of the procedure were evaluated. Results Ease of fragmentation and completeness of capsulotomy were estimated at 3.9 and 9.9, respectively. The preparation time for femtosecond was 3.6±0.7 minutes, effective phacoemulsification time was 2.5±3.1 seconds, and total duration of the FLACS procedure was 16.3±4.5 minutes. No major complications were observed. Approximately 42% of all patients (6/14) showed Descemet’s folds directly postoperatively. Conclusion FLACS with the LDV Z8 system was characterized by complete capsulotomy and highly effective and reproducible lens fragmentation. The safety of the procedure was very good as perceived by the surgeon operating in this observational case series. The cost to benefit ratio should be further debated by assessing the results of a major prospective study, which is required for valid evaluation of the efficiency and safety of the LDV Z8 laser system and of FLACS in general.

Evaluation of the efficacy of the Allegretto Wave and the Wavefront‐optimized ablation profile in non‐anterior astigmatisms

Purpose:  To assess the efficacy of the Allegretto Wave and the wavefront‐optimized ablation profile (WFO) in non‐anterior astigmatism correction, in both LASIK and photorefractive keratectomy (PRK) treatments.