Clinical experience of switching anti-VEGF therapy from ranibizumab to aflibercept in age-related choroidal neovascularization.

PURPOSE: To report the response of participants switching from ranibizumab to aflibercept treatment for neovascular age-related macular degeneration (nAMD) requiring further anti-vascular endothelial growth factor treatment. METHODS: In this retrospective case review of 68 participants treated in a single hospital, all participants, prior to switching, received ranibizumab injections only. Best-corrected visual acuity (BCVA), clinical examination, and optical coherence tomography (OCT) were performed at each visit. Active nAMD was defined as persistent intraretinal or subretinal fluid on OCT. Participants had their first aflibercept injection at baseline and 2 more injections at 2 monthly intervals. Afterwards, they were followed up every 6-8 weeks and given injections as needed. The main outcome measures were visual acuity and the OCT central retinal thickness (CRT), average thickness (AT), and total macular volume (TMV). RESULTS: The BCVA at baseline visit was 0.57 ± 0.33 log MAR and the final BCVA was 0.54 ± 0.37 log MAR (p = 0.215). The CRT mean change was -75.6 ± 85.6 (p = 0.001), the AT mean change was -24.2 ± 27.2 (p = 0.001), and TMV mean change was -0.69 ± 0.78 (p = 0.001). There were no significant ophthalmic complications related to treatments. CONCLUSIONS: Intravitreal aflibercept improved anatomic outcomes (as measured by OCT) in eyes with nAMD that were previously treated with intravitreal ranibizumab and were still active. There was no statistically significant difference in logMAR visual acuity in participants who switched to aflibercept with a follow-up of at least 6 months.

Biomechanical and optical behavior of human corneas before and after photorefractive keratectomy.

PURPOSE: To evaluate numerically the biomechanical and optical behavior of human corneas and quantitatively estimate the changes in refractive power and stress caused by photorefractive keratectomy (PRK). SETTING: Athineum Refractive Center, Athens, Greece, and Politecnico di Milano, Milan, Italy. DESIGN: Retrospective comparative interventional cohort study. METHODS: Corneal topographies of 10 human eyes were taken with a scanning-slit corneal topographer (Orbscan II) before and after PRK. Ten patient-specific finite element models were created to estimate the strain and stress fields in the cornea in preoperative and postoperative configurations. The biomechanical response in postoperative eyes was computed by directly modeling the postoperative geometry from the topographer and by reproducing the corneal ablation planned for the PRK with a numerical reprofiling procedure. RESULTS: Postoperative corneas were more compliant than preoperative corneas. In the optical zone, corneal thinning decreased the mechanical stiffness, causing local resteepening and making the central refractive power more sensitive to variations in intraocular pressure (IOP). At physiologic IOP, the postoperative corneas had a mean 7% forward increase in apical displacement and a mean 20% increase in the stress components at the center of the anterior surface over the preoperative condition. CONCLUSION: Patient-specific numerical models of the cornea can provide quantitative information on the changes in refractive power and in the stress field caused by refractive surgery. FINANCIAL DISCLOSURES: No author has a financial or proprietary interest in any material or method mentioned.

Optical coherence tomography, Scheimpflug imaging, and slit-lamp biomicroscopy in the early detection of graft detachment after Descemet membrane endothelial keratoplasty.

PURPOSE: To evaluate the efficacy of anterior segment optical coherence tomography (OCT), Scheimpflug imaging, and slit-lamp biomicroscopy in the early detection of a (partial) graft detachment after Descemet membrane endothelial keratoplasty (DMEK). METHODS: Anterior segment OCT, Scheimpflug imaging, and slit-lamp biomicroscopy were performed in 120 eyes of 110 patients after DMEK. RESULTS: Seventy-eight eyes showed a normal corneal clearance, and the attached Descemet grafts could not be identified with any of the imaging techniques. Forty-two eyes showed persistent stromal edema in the first postoperative month. In transplanted corneas that (partially) did not clear in the early postoperative period, OCT had an added diagnostic value in 36% of cases (15 of 42 eyes) in visualizing whether the graft was detached and, in particular, to discriminate between a "flat" graft detachment and delayed corneal clearance. In contrast, in the presence of corneal edema, Scheimpflug imaging did not provide more information than slit-lamp biomicroscopy in the detection of a graft detachment. CONCLUSIONS: Anterior segment OCT may be an effective tool in the detection of an early graft detachment after DMEK, to determine if secondary surgical intervention is indicated or is to be avoided.

Learning Curve in Descemet's Membrane Endothelial Keratoplasty: First Series of 135 Consecutive Cases.

PURPOSE: To evaluate the learning curve in Descemet's membrane endothelial keratoplasty (DMEK) in the management of corneal endothelial disorders. DESIGN: Retrospective, nonrandomized, clinical study at a tertiary referral center. PARTICIPANTS: We included 135 eyes of 118 patients with Fuchs' endothelial dystrophy. METHODS: In a first group of 135 consecutive eyes, a DMEK was performed. To determine the extent of a possible learning curve in DMEK surgery, the whole group was divided into 3 subgroups of 45 patients, to compare clinical outcomes at 1, 3, and 6 months. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA), endothelial cell density (ECD), and intra- and postoperative complications. RESULTS: Among the 3 groups clinical outcomes were similar, with 73% of cases achieving a BCVA of ≥20/25 (≥0.8) and an average ECD of 1747 ± 527 cells/mm², at 6 months. Graft detachment was the main complication and correlated with intraoperative vitreous pressure (P<0.01). The detachment rate declined with experience: In the first 45 cases, a complete or partial graft detachment occurred in 20%, in the second group in 13.3%, and in the third group in 4.4%. Other complications were relatively uncommon: Failure to unfold or position the graft during surgery (0.7%), intraocular hemorrhage (0.7%), primary graft failure (2.2%), air-bubble induced angle closure glaucoma (3%), remnant host Descemet's at the interface (5.9%), and cystoid macular edema (0.7%). Surgeries (partially) performed by an inexperienced surgeon showed a similar clinical outcome and complication rate. CONCLUSIONS: The learning curve in DMEK did not correlate with clinical outcome (BCVA and ECD), but rather to the presence of a functional graft. However, the number of functional grafts (decline in graft detachment rate) increased with surgical experience. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosures may be found after the references.

Refractive change and stability after Descemet membrane endothelial keratoplasty. Effect of corneal dehydration-induced hyperopic shift on intraocular lens power calculation.

PURPOSE: To determine the refractive change and stability of the transplanted cornea after Descemet membrane endothelial keratoplasty (DMEK) through a 3.0 mm clear corneal incision. SETTING: Tertiary referral center. DESIGN: Cohort study. METHODS: Subjective and objective refractive data from pseudophakic eyes were obtained before and 3 and 6 months after DMEK. RESULTS: The study comprised 50 eyes, 7 were phakic and 43 pseudophakic. Six months postoperatively, the corrected distance visual acuity was 20/25 (0.8) or better in 38 eyes (74%). The mean increase in spherical equivalent at 6 months (N = 50) was +0.32 diopter (D) ± 1.01 D (SD) (P=.0304) and in refractive cylinder, -0.48 ± 1.02 D (P=.001). Although Scheimpflug imaging showed a stable anterior corneal curvature, the posterior curvature increased from 5.50 ± 0.5 D preoperatively to 6.40 ± 0.4 D at 6 months and pachymetry decreased from 672 ± 82 µm to 540 ± 59 µm, respectively (both N = 32) (both P=.000). CONCLUSIONS: After DMEK, a slight preoperative to postoperative refractive change and stabilization at 3 months occurred that may induce a hyperopic shift that was not the result of the negative lenticule effect of DSEK/DSAEK. Thus, in DMEK, the hyperopic shift may result from a reversal of a preceding myopic shift induced by stromal swelling in endothelial disease. If so, normal intraocular power nomograms apply for cataract surgery before or during DMEK.

Efficacy of descemet membrane endothelial keratoplasty: clinical outcome of 200 consecutive cases after a learning curve of 25 cases.

OBJECTIVE: To evaluate Descemet membrane endothelial keratoplasty for management of corneal endothelial disorders. METHODS: Descemet membrane endothelial keratoplasty was performed in 200 patients with Fuchs endothelial dystrophy or bullous keratopathy. Best-corrected visual acuity, subjective and objective refractive outcome and stability, and endothelial cell density were evaluated at 1, 3, and 6 months postoperatively, and intraoperative and postoperative complications were documented. RESULTS: At 6 months, 94% reached a best-corrected visual acuity of 20/40 or better (≥0.5); 77%, 20/25 or better (≥0.8); 47%, 20/20 or better (≥1.0), and 16%, 20/17 or better (≥1.2) (n = 159). The preoperative to 6 months' postoperative spherical equivalent showed a mean (SD) +0.38 (1.2) diopter hyperopic shift (P = .001) that correlated with a decrease in central corneal thickness (n = 143) (P = .047). Two-thirds of eyes showed refractive stability at 3 months. Donor endothelial cell density showed a decrease from mean (SD) 2560 (186) cells/mm(2) preoperatively to 1690 (520) cells/mm(2) at 6 months after surgery (n = 173) (P < .001). Graft detachment was the main complication and occurred in 18 eyes (9%). Recipient Descemet membrane remnants were present in 12 eyes (6%). Secondary glaucoma was seen in 8 eyes (4%), of which 4 showed air-bubble dislocation behind the iris. In 2 of 33 phakic eyes (6%), a secondary cataract developed requiring phacoemulsification. CONCLUSIONS: Descemet membrane endothelial keratoplasty may offer complete visual rehabilitation within 1 to 6 months after surgery in a majority of eyes. Similar to earlier keratoplasty techniques, Descemet membrane endothelial keratoplasty may be associated with a one-third decrease in donor endothelial cell density in the early postoperative phase. Incidence of (partial) graft detachment stabilized at about 5% but could be further reduced by patient selection and/or technique modification. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00521898.

Standardized "no-touch" technique for descemet membrane endothelial keratoplasty.

We describe a standardized technique for "no-touch" isolated Descemet membrane transplant, ie, Descemet membrane endothelial keratoplasty (DMEK). All essential steps, including patient preparation and descemetorhexis as well as DMEK graft implantation, orientation, unrolling, centering, appositioning, and fixation, are described in detail. In the management of Fuchs endothelial dystrophy, the technique may provide a best-corrected visual acuity of 20/25 or better (≥ 0.8) in three-quarters of cases and an endothelial cell density of about 1800 to 2000 cells/mm(2) at 6 months after surgery. No-touch DMEK may therefore be a safe and effective procedure for the treatment of corneal endothelial disorders, making endothelial keratoplasty accessible to most corneal surgeons without requiring major investments while providing an unprecedented visual rehabilitation rate and outcome.