PURPOSE: To evaluate corneal stiffening in porcine eyes induced by corneal cross-linking (CXL) using riboflavin dissolved in either aqueous dextran or hydroxypropyl methylcellulose (HPMC) solution. METHODS: Fifty-one porcine corneas were divided into three groups of 17 each. After deepithelialization, the first (Dresden) group was treated for 30 minutes with 0.1% riboflavin (riboflavin-5-monophosphate in 0.9% NaCl) dissolved in hypertonic 20% dextran and the second (HPMC) group for 30 minutes with isotonic solution containing 0.1% riboflavin and 1.1% HPMC. Thereafter, corneas of both groups were irradiated using 5.4 J/cm 2 (irradiance of 9 mW/cm 2 for 10 minutes; 10*9). After CXL, all corneas were kept in an isotonic 16% dextran bath for 2 hours to obtain an equal hydration state. The third group served as the control group. Stress-strain measurements were performed on 5-mm–wide strips. Corneal thickness was monitored throughout the entire course of the experiments. RESULTS: The required stress for a 10% strain was increased by 83% in the Dresden group and 35% in the HPMC group compared to the control group. Resultant Young's modulus (at 10% strain) was 2.53 ± 0.73, 1.87 ± 0.50, and 1.47 ± 0.44 Pa for the Dresden, HPMC, and control groups, respectively. The differences between the Dresden and HPMC groups ( P = .006), the Dresden and control groups ( P < .001), and the HPMC and control groups ( P = .014) were statistically significant. Pachymetry measurements showed a significantly increased corneal thickness after application of HPMC compared with the Dresden group ( P = .002) and control group ( P = .041). CONCLUSIONS: The biomechanical stiffening of the cornea by CXL can be achieved using dextran- and HPMC-based riboflavin solutions in porcine corneas with an application time of 30 minutes. Dextran-based riboflavin solutions seem to induce a slightly stronger biomechanical response in this setting. HPMC solutions induce less thinning than dextran solutions. [ J Refract Surg . 2021;37(9):631–635.]

Purpose To evaluate the influence of the type of the keratectasia and preoperative keratometry readings on the efficacy of implantation of iris-fixated phakic anterior chamber intraocular lenses (pIOL) in patients with keratoconus. Methods In this retrospective study, iris-fixated pIOLs (Artisan/Artiflex (Ophtec®), Verisyse/Veriflex (AMO®)) were implanted in 38 eyes of 22 patients with stable keratoconus. Thirty-six eyes underwent corneal crosslinking (CXL) prior to the lens implantation. The refractive outcome was evaluated 6 weeks postoperatively and the influence of preoperative refraction and topo- and tomographical factors were analyzed. Results The mean postoperative uncorrected distance visual acuity (UDVApost) was 0.25 ± 0.15 logMAR and was not statistically different from the mean preoperative corrected distance visual acuity (CDVApre), which was 0.24 ± 0.13 logMAR. Twenty-seven eyes (71%) reached UDVApost/CDVApre ≥ 1 (efficacy index), whereas patients with PMD-like ectasia (n = 14) showed significantly (p = 0.003) higher efficacy index (100%) than patients diagnosed with keratoconus (n = 24) (54%). Higher eccentricity of the maximum posterior elevation showed a significant beneficial influence on the efficacy index (p = 0.021). Furthermore, a higher Amsler-Krumeich stage and preoperative MAE were correlated with a worse UDVApost. The mean absolute spherical equivalent was significantly decreased from 5.71 ± 4.96 D to 1.25 ± 1.20 D (p < 0.001). No significant difference was found in endothelial cell count. Conclusion The results indicate that the implantation of phakic iris-fixated anterior chamber IOLs is a reasonable refractive option for patients with keratoconus. Keratoconus patients with a pellucidal marginal degeneration (PMD)-like appearance ectasia seem to benefit most from such procedures.

Intravitreal anti-VEGF therapy is the gold standard in the treatment of neovascular age-related macular degeneration (nAMD). In recent literature, the benefit of additional photodynamic therapy (PDT) has been debated. The aim of our study was to compare the functional and structural effects of long-term combination therapy with PDT plus ranibizumab with monotherapy with ranibizumab. In a retrospective study, patients suffering from nAMD were followed up for at least 42 months. Patients were assigned to group A (monotherapy with ranibizumab according to pro re nata [PRN]) or group B (combination therapy with one-time PDT plus ranibizumab according to PRN). The best-corrected visual acuity (BVCA) was evaluated at the starting and end points, together with central retinal thickness (CRT), maximal retinal thickness (MRT) and the maximal diameter of the base of the subretinal plaque in spectral-domain optical coherence tomography (SD-OCT), at the first measurement and at the end point. Group A consisted of 21 eyes (17 patients) and group B consisted of 12 eyes (11 patients). The average follow-up from starting to end point was 64 months and 47 months, from the first measurement of SD-OCT to the end point. Within this period, patients in group A received 19 ± 14 intravitreal injections, and patients in group B received 22 ± 10 intravitreal injections. BCVA at the starting point was 0.31 ± 0.26 in group A and 0.31 ± 0.17 in group B. At the end point, BCVA in group A was 0.29 ± 0.25 (p = 0.405), and in group B 0.25 ± 0.20 (p = 0.142). CRT decreased in group A by 72 ± 178 µm (p = 0.024) and group B by 28 ± 98 (p = 0.1335). MRT decreased in group A by 25 ± 135 µm (p = 0.166) and in group B by 2 ± 118 µm (p = 0.421). The base of the subretinal plaque increased in group A by 32 ± 1468 µm (p = 0.242) and in group B by 748 ± 1024 (p = 0.025). In a long-term follow-up of 5.3 years, patients with nAMD in both groups exhibited good stabilisation of visual acuity. In both groups, retinal thickness decreased and the base of the subretinal plaque increased. With respect to SD-OCT morphological criteria, patients in group A (monotherapy) responded slightly better to therapy than patients in group B (combination group).

Introduction To report a late onset, deep stromal and endothelial corneal scar in a keratoconus patient after corneal collagen cross-linking (CXL). Case description Observational case report. A 29-year-old man with bilateral keratoconus received an accelerated (A-CXL 10*9) epithelium-off CXL procedure in the left eye. 6-months postoperatively, a 2.2 × 1.2 mm inferocentral corneal scar was detected, which was located in the posterior stroma ranging from approximately 350 µm until the endothelium, therefore was situated below the demarcation line. A topical corticosteroid treatment did not influence the magnitude or configuration of the scar. Visual acuity was never affected, which includes the examination 12 months postoperatively. Conclusions We report a case of a late onset deep stromal and endothelial corneal scar 6 months after accelerated CXL as postoperative complication without affecting visual acuity.