Safety and Efficacy of Repeated Corneal Collagen Crosslinking in Progressive Keratoconus.

PURPOSE: Keratoconus is a progressive visually impairing disorder. Despite the beneficial effects of epithelial off-crosslinking (CXL) on the stabilization of keratoconus, progression may still occur. We report the efficacy and safety of a repeated CXL for significant progression of keratoconus after a single CXL procedure. METHODS: This retrospective study includes patients diagnosed with progressive keratoconus who were previously treated with CXL and underwent repeated CXL. Demographic, clinical, and surgical data were retrieved and analyzed. RESULTS: Ten consecutive eyes of nine patients who developed progressive keratoconus after CXL were identified. The mean age at diagnosis of keratoconus was 20.2 ± 6.0 years. The post-repeated CXL follow-up period was 2.1 ± 1.3 years. The mean best corrected visual acuity (BCVA) remained stable throughout the follow-up period. The mean Kmax at baseline was 60.4 ± 3.6 D. Before the repeated CXL, Kmax progressed significantly ( P = 0.018) and was 62.2 ± 6.3 D, and at the last follow-up, the value decreased significantly ( P = 0.037) and was 60.3 ± 6.4 D. The mean minimal pachymetry was 464.0 ± 27.0 µ at base line. Before the repeated CXL, minimal pachymetry was significantly lower ( P = 0.018), and after the repeated CXL, the minimal pachymetry was stable ( P = 0.2). No intra- or postoperative complications were noted. CONCLUSIONS: Repeated CXL is a safe and effective treatment option when failure of the initial CXL is diagnosed, even in young patients. This procedure may prevent visual deterioration and a potential need for keratoplasty.

Minimally Invasive Micro Sclerostomy (MIMS) Procedure: A Novel Glaucoma Filtration Procedure.

PRCIS: Intermediate-term results suggest that ab interno Minimally Invasive Micro Sclerostomy (MIMS) stent-less subconjunctival filtration procedure is a promising treatment option for patients with open-angle glaucoma (OAG). PURPOSE: MIMS is a novel ab interno, stent-less, subconjunctival filtration procedure. This study set to investigate the safety, performance, and efficacy of MIMS in OAG patients. METHODS: Prospective, open-label, single arm clinical trial with intrasubject comparisons. Study participants were adults with OAG who were candidates for a filtration procedure. Patients were operated by a single surgeon (A.A.) in Chennai, India. Following mitomycin-C pretreatment, ab interno MIMS procedure was performed alone or combined with phacoemulsification surgery. Procedure-related complications and adverse events were assessed. Primary outcomes: patients (%) achieving an intraocular pressure (IOP) ≥5 mm Hg and ≤18 mm Hg, and an IOP reduction of >20% as compared with baseline, with or without hypotensive medications, with no need for recurrent surgery. RESULTS: Twenty-one phacoemulsification-MIMS and 10 standalone MIMS procedures were performed. Mean age was 63.94±6.33 years. Mean duration of MIMS was 1:58±0:25 (min:s). Scleral tunnels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Five (16.12%) patients presented with iris clogging 1 to 24 weeks following procedure. Two were treated with laser and 3 required trabeculectomy. Mean IOP change from baseline at 24 weeks was 47.4% (31.2 to 16.4 mm Hg, P<0.0001, n=23). The mean difference was -14.8 mm Hg (95% confidence interval: -17.6, -11.9) with no statistically significant differences between groups. Qualified success was achieved in 21 (84%), 17 (74%), and 13 (93%) after 12, 24, and 52 weeks, respectively. Complete success was achieved in 17 (68%), 13 (57%), and 8 (57%) after 12, 24, and 52 weeks, respectively. CONCLUSIONS: The interim results suggest that MIMS procedure may be a simple and effective surgical option for early OAG patients requiring target IOP in high teens although iris clogging of incision site is the major concern with this procedure.

Load to Failure of the Ankle Joint Complex After Fusion of the Subtalar and Talonavicular Joints: A Cadaveric Study.

Recent literature has proposed that restriction of joints in the rearfoot secondary to coalitions may lead to increased risk for severe ankle fracture after trauma. There is a paucity of literature regarding the rigidity of the ankle joint after arthrodesis of the subtalar and talonavicular joints. In this study, load-to-failure testing of cadaveric ankle joints with and without fusion of the subtalar and talonavicular joints was performed to determine if clinically relevant fracture patterns could be reproduced. Of the 3 fixation patterns studied, combined subtalar and talonavicular joint fusion resulted in a measurable increase in joint stiffness; however, this was not statistically significant. Clinical and radiographic examination postloading revealed that all tested ankle joints sustained a dislocation type injury rather than a specific bone fracture pattern. It was determined that a pure low-speed bending and compression model does not produce clinically relevant fracture patterns, and that higher energy mechanisms are required.

MIMS Procedure: Concept and Evaluation of Safety, Feasibility, and Efficacy in a Porcine Experimental Model.

PRECIS: We present a novel stentless filtration system used to create a permanent sclerocorneal drainage channel that reduces intraocular pressure (IOP) without the need to create a conjunctival incision or a scleral flap. PURPOSE: The purpose of this study was to evaluate the safety, feasibility, and preliminary performance of a novel surgical system, the minimally invasive micro sclerostomy (MIMS), in an in vivo porcine experimental model. MATERIALS AND METHODS: MIMS is an ab externo stentless filtration procedure. An activation system is used to operate a handpiece that includes a 600 µm needle containing an injectable 300 µm triangular blade that spins around its longitudinal axis. The needle is inserted into the subconjunctival space and the blade is injected at the limbal area creating a drainage channel at the sclerocorneal junction, connecting the anterior chamber to the subconjunctival space. The first generation of the MIMS surgical system was assessed in a porcine experimental model, firstly on 6 pigs and thereafter on 10 pigs. All adverse events, IOP measurements, and bleb descriptions were recorded for up to 14 weeks. The shape and location of the scleral tunnel, the subconjunctival bleb, and the healing process were examined by slit-lamp examination, by histopathologic analysis, and by anterior segment optical coherence tomography imaging. RESULTS: No device malfunctions were recorded. Scleral tunnels were repeatedly achieved in all models. No significant intraoperative or postoperative complications were recorded. Effective fluid percolation was achieved in all eyes. The mean IOP statistically significantly decreased from 19.0±3.2 mm Hg preoperatively to 11.1±4.9 mm Hg on the first follow-up visit (P=0.0046) in the first leg of the study, and from 18.5±3.8 to 13.3±1.9 mm Hg in the second leg (P=0.0165). In both, IOP gradually returned to preoperative values toward the end of the follow-up period, as expected in a porcine experimental model. Histologic analysis of the analyzed tissue was not associated with significant tissue reaction. CONCLUSIONS: The MIMS procedure exhibited a consistent and relatively high safety, feasibility, and efficacy profiles. In the future, the MIMS procedure may provide a novel solution for uncontrolled IOP.

Graft Survival After Penetrating and Endothelial Keratoplasty in Iridocorneal Endothelial Syndrome.

PURPOSE: To compare the survival of a first penetrating keratoplasty (PK) or endothelial keratoplasty (EK) for iridocorneal endothelial (ICE) syndrome with transplant survival in Fuchs endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK). METHODS: We compared graft survival of PK and EK for ICE syndrome for 2 time periods. We then compared graft survival in ICE syndrome with graft survival in FED and PBK. Kaplan-Meier estimates of graft survival up to 5 years posttransplant were calculated with 95% confidence intervals (CI), whereas comparisons between the groups were performed using the log-rank test. RESULTS: We included 86 first transplants for ICE syndrome. There was no difference in graft survival between the 58 PKs and the 28 EKs for up to 5 years after surgery (P = 0.717). For the period from 2009 to 2017, the 5-year graft survival rates for ICE syndrome were 64.3% (CI, 21.8%-88.0%) for the 16 PKs and 66.8% (CI, 41.8%-83.0%) for the 26 EKs (P = 0.469). Between 2009 and 2017, the 5-year survival rate for 42 grafts with ICE syndrome was 62.7% (CI, 39.6%-79.0%), which was lower than 75.9% (CI, 74.2%-77.4%) in 7058 transplants for FED but higher than 55.1% (CI, 52.0%-58.0%) in 3320 transplants for PBK, although the numbers of ICE transplants are too small to tell whether this difference was by chance. CONCLUSIONS: The results indicate no difference in graft survival between PK and EK for ICE syndrome. Graft survival in ICE syndrome is intermediate between that of FED and PBK.

Intraocular lens power calculation for eyes with an axial length greater than 26.0 mm: comparison of formulas and methods.

PURPOSE: To evaluate and compare the accuracy of formulas and methods for calculating the intraocular lens (IOL) power for eyes with an axial length (AL) greater than 26.0 mm. SETTING: Ein-Tal Eye Center, Tel-Aviv, Israel. DESIGN: Retrospective case series. METHODS: The postoperative refraction results in myopic eyes with an AL over 26.0 mm were compared with the predicted refractions calculated using standard formulas (Holladay 1, SRK/T, Hoffer Q, and Haigis) with optical IOL constants, User Group for Laser Interference Biometry constants, and an AL-adjustment method and using new-generation formulas (Barrett Universal II, Holladay 2, and Olsen). RESULTS: In 76 (71.7%) of 106 eyes, the IOL was 6.0 diopters (D) or more (Group A) and in 30 eyes (28.3%) was less than 6.0 D (Group B). In Group A, the SRK/T, Hoffer Q, Haigis, Barrett Universal II, Holladay 2, and Olsen methods met the benchmark criteria of having a prediction error of ±0.5 D in at least 71.0% of eyes and ±1.0 D in 93.0% of eyes. In Group B, only the Barrett Universal II formula and the Holladay 1 and Haigis formulas using the AL-adjusted method met those criteria. CONCLUSION: When selecting IOLs for high and extreme myopia, choosing appropriate formulas and methods can yield accurate refractive results that meet benchmark criteria. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Penetration of moxifloxacin through crosslinked corneas.

PURPOSE: To determine the ability of moxifloxacin to penetrate the rabbit eye after corneal collagen crosslinking (CXL) with riboflavin and ultraviolet-A light irradiation. SETTING: Harlan Biotech Israel, Rehovot, Israel. DESIGN: Experimental study. METHODS: One eye of 10 New Zealand white rabbits had CXL treatment. One month after treatment and 1 hour before an aqueous humor sample was obtained, 1 drop of 5 mg/mL moxifloxacin (Vigamox) was applied to both eyes of each rabbit every 15 minutes for a total of 4 drops. The aqueous humor samples were sent for high-performance liquid chromatography for antibiotic-concentration analysis. The eyes were enucleated and sent for histology analysis. RESULTS: Moxifloxacin levels were obtained and analyzed for all 20 eyes. The mean level of moxifloxacin was 2.26 µg/mL ± 0.89 (SD) (range 1.09 to 4.20 µg/mL) in the treated eyes and 2.43 ± 1.17 µg/mL (range 0.89 to 4.72 µg/mL) in the untreated eyes. The difference between the groups was not statistically significant. Of the 10 eye pairs, lower moxifloxacin aqueous humor concentrations were found in 6 treated eyes and 4 untreated eyes. CONCLUSION: Penetration of moxifloxacin into the anterior chamber of rabbits was not influenced by previous CXL treatment. FINANCIAL DISCLOSURES: No author has a financial or proprietary interest in any material or method mentioned.