Korine van Dijk

Near complete visual recovery and refractive stability in modern corneal transplantation: Descemet membrane endothelial keratoplasty (DMEK)

OBJECTIVE To report the 6 months results of a large prospective study on Descemet membrane endothelial keratoplasty (DMEK) for management of corneal endothelial disorders. METHODS DMEK was performed in 300 consecutive eyes with Fuchs endothelial dystrophy, bullous keratopathy or previous corneal transplant failure. Best spectacle corrected visual acuity (BSCVA), refractive outcome and endothelial cell density (ECD) were evaluated before and at 1, 3, and 6 months after surgery. Intra- and postoperative complications were documented. RESULTS At 6 months, 98% of eyes reached a BCVA of ≥20/40 (≥0.5), 79% ≥20/25 (≥0.8), 46% ≥20/20 (≥1.0), and 14% ≥20/18 (≥1.2) (n=221). The pre- to 6 months postoperative spherical equivalent (SE) showed a +0.33D (±1.08D) hyperopic shift (P=0.0000). Refractive stability was shown at 3 months after DMEK, i.e. no significant change in SE (P=0.0822) or refractive cylinder (P=0.6182) at 3 versus 6 months follow-up. Donor ECD showed a decrease from 2561 (±198)cells/mm(2) before, to 1674 (±518)cells/mm(2) at 6 months after surgery (n=251) (P=0.0000). The main complication was (partial) graft detachment occurring in 31 eyes (10%). Secondary ocular hypertension was seen in 13 eyes (6%): 6 induced by air-bubble dislocation posterior to the iris and 4 induced by steroids. Secondary cataract requiring phaco-emulsification developed in 3 out of 63 (5%) phakic eyes. CONCLUSIONS DMEK may provide a refractively neutral near complete, rapid visual rehabilitation with ECDs similar to earlier endothelial keratoplasty techniques. This combined with a relatively low complication rate, would indicate that DMEK is a safe and effective treatment for corneal endothelial disorders.

Prevention and Management of Graft Detachment in Descemet Membrane Endothelial Keratoplasty

OBJECTIVE To describe the prevention and management of various types of graft detachment after Descemet membrane endothelial keratoplasty. METHODS In 150 consecutive eyes that underwent Descemet membrane endothelial keratoplasty, the incidence and type of graft detachment were studied at 1, 3, 6, 9, 12, and 24 months after surgery in a nonrandomized, prospective clinical study at a tertiary referral center. Four groups of detachments were identified: a partial detachment of one-third or less of the graft surface area (n = 16; group 1); a partial detachment of more than one-third of the graft surface area (n = 8; group 2); a graft positioned upside down (n = 4; group 3); and a free-floating Descemet roll in the host anterior chamber (n = 8; group 4). RESULTS Partial or complete graft detachment was found in 36 cases (24%), of which 18 (12%) were clinically significant. All 24 eyes with a partial detachment (groups 1 and 2) showed spontaneous corneal clearance, and all but 6 of these eyes (75%) reached visual acuity of 20/40 or better (≥0.5). A reversed clearance pattern and interface spikes were observed in eyes with the graft positioned upside down (group 3). Eyes with a free-floating graft (group 4) showed persistent corneal edema. Detachments were associated with inward folds (12 eyes [33%]), insufficient air-bubble support (7 eyes [19%]), upside-down graft positioning (4 eyes [11%]), use of plastic materials (2 eyes [6%]), irido-graft synechiae (1 eye [3%]), poor endothelial morphology (1 eye [3%]), and stromal irregularity under the main incision (1 eye [3%]); 14 (58%) of the partial detachments were localized inferiorly. CONCLUSIONS Awaiting spontaneous clearance may be advocated in eyes with a partial detachment. Minor adjustments in surgical protocol as well as careful patient selection may further reduce the incidence of graft detachment after Descemet membrane endothelial keratoplasty to 4% or less. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00521898.

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. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Intraocular Graft Unfolding Techniques in Descemet Membrane Endothelial Keratoplasty

OBJECTIVE To define various Descemet graft unfolding techniques in Descemet membrane endothelial keratoplasty. METHODS In a retrospective analysis, the surgical videos of 100 consecutive Descemet membrane endothelial keratoplasty cases with at least 6 months of follow-up were evaluated and categorized. The Descemet graft unfolding methods were categorized into 4 basic techniques and 3 auxiliary techniques. RESULTS All Descemet membrane endothelial keratoplasty surgical procedures could be completed using (a combination of) 4 Descemet graft unfolding techniques: (1) standardized no-touch graft unfolding using a double roll, (2) carpet unrolling while fixating 1 graft edge (Dirisamer technique), (3) small air bubble-assisted unrolling (Dapena maneuver), (4) the single sliding cannula maneuver. Additional maneuvers included turning over the graft when oriented upside down (flushing); manual graft centration with a cannula; and bubble bumping to unfold peripheral inward folds. In 73% of surgical procedures, technique 1 was used, while a combination of techniques was used in 44% and auxiliary techniques in 62%. None of the techniques showed a correlation with the best-corrected visual acuity, endothelial cell density, or postoperative complication rate (P > .10). CONCLUSIONS Descemet membrane endothelial keratoplasty may be further facilitated by using controlled techniques for unfolding the Descemet graft inside the recipient anterior chamber, either as stand-alone techniques or used in various combinations.

Outcomes of Descemet membrane endothelial keratoplasty in phakic eyes

PURPOSE: To determine the clinical outcomes of isolated Descemet membrane transplantation (ie, Descemet membrane endothelial keratoplasty [DMEK]) in phakic eyes. SETTING: Tertiary referral center. DESIGN: Cohort study. METHODS: Phakic eyes from a larger group of consecutive eyes that had DMEK for Fuchs endothelial dystrophy were examined. The examination included corrected distance visual acuity (CDVA), subjective and objective refractions, endothelial cell density (ECD), and intraoperative and postoperative complications at 1, 3, and 6 months. RESULTS: The study enrolled 52 phakic eyes from a group of 260 DMEK eyes. Of the phakic eyes, 69% reached a CDVA equal to or better than 20/40 (≥0.5) within 1 week and 85% reached equal to or better than 20/25 (≥0.8) at 6 months. Compared with an age‐matched control group of pseudophakic eyes, phakic eyes had a similar visual rehabilitation rate, final visual outcome, mean ECD at 6 months (1660 cells/mm2 ± 470 [SD]), minor hyperopic shift (+0.74 diopter), and graft detachment rate (4%). Visual acuity equal to or better than 20/13 (≥1.5) was limited to phakic eyes, suggesting better optical quality with the crystalline lens in situ. Temporary mechanical angle‐closure glaucoma due to air‐bubble dislocation behind the iris was the main complication (11.5%). Two eyes (4%) required phacoemulsification after DMEK. CONCLUSIONS: In phakic eyes, DMEK may give excellent visual outcomes without an increased risk for complications. Visual acuities equal to or better than 20/13 (≥1.5) may indicate that the almost anatomic repair after DMEK is associated with near perfect optical quality of the transplanted cornea. Financial Disclosure: Dr. Melles is a consultant to D.O.R.C. International/Dutch Ophthalmic USA. No author has a financial or proprietary interest in any material or method mentioned.

Treatment options for advanced keratoconus: A review

Traditionally, the mainstay of treatment for advanced keratoconus (KC) has been either penetrating or deep anterior lamellar keratoplasty (PK or DALK, respectively). The success of both operations, however, has been somewhat tempered by potential difficulties and complications, both intraoperatively and postoperatively. These include suture and wound-healing problems, progression of disease in the recipient rim, allograft reaction, and persistent irregular astigmatism. Taken together, these have been the inspiration for an ongoing search for less troublesome therapeutic alternatives. These include ultraviolet crosslinking and intracorneal ring segments, both of which were originally constrained in their indication exclusively to eyes with mild to moderate disease. More recently, Bowman layer transplantation has been introduced for reversing corneal ectasia in eyes with advanced KC, re-enabling comfortable contact lens wear and permitting PK and DALK to be postponed or avoided entirely. We offer a summary of the current and emerging treatment options for advanced KC, aiming to provide the corneal specialist useful information in selecting the optimal therapy for individual patients.

Repeat Descemet membrane endothelial keratoplasty after complicated primary Descemet membrane endothelial keratoplasty.

PURPOSE To describe the clinical outcome and complications of repeat Descemet membrane endothelial keratoplasty (re-DMEK). DESIGN Retrospective case series study at a tertiary referral center. PARTICIPANTS From a series of 550 consecutive DMEK surgeries with ≥ 6 months follow-up, 17 eyes underwent re-DMEK for graft detachment after initial DMEK (n = 14) and/or endothelial graft failure (n = 3). The outcomes were compared with an age-matched control group of uncomplicated primary DMEK surgeries. METHODS The re-DMEK eyes were evaluated for best-corrected visual acuity (BCVA), densitometry, endothelial cell density (ECD), pachymetry, and intraoperative and postoperative complications. MAIN OUTCOME MEASURES Feasibility and clinical outcome of re-DMEK. RESULTS In all eyes, re-DMEK was uneventful. At 12 months, 12 of 14 eyes (86%) achieved a BCVA of ≥ 20/40 (≥ 0.5); 8 of 14 eyes (57%) achieved ≥ 20/25 (≥ 0.8), 3 of 14 eyes (21%) achieved ≥ 20/20 (≥ 1.0), and 1 eye (7%) achieved 20/17 (1.2); 5 eyes were fitted with a contact lens. Average donor ECD decreased from 2580 ± 173 cells/mm(2) before to 1390 ± 466 cells/mm(2) at 6 months after surgery, and pachymetry from 703 ± 126 μm to 515 ± 39 μm, respectively. No difference in densitometry could be detected between re-DMEK and control eyes (P = 0.99). Complications after re-DMEK included primary graft failure (n = 1), secondary graft failure (n = 2), graft detachment requiring rebubbling (n = 1), secondary glaucoma (n = 2), cataract (n = 1), and corneal ulcer (n = 1). One eye received tertiary DMEK. CONCLUSIONS In the management of persistent graft detachment and graft failure after primary DMEK, re-DMEK proved a feasible procedure. Acceptable BCVA may be achieved, albeit lower than after DMEK in virgin eyes, and some cases may benefit from contact lens fitting. Complications after re-DMEK may be better anticipated than after primary DMEK because graft detachment and graft failure tended to recur, suggesting that intrinsic properties of the host eye play a role in graft adherence and graft failure.

Identifying causes for poor visual outcome after DSEK/DSAEK following secondary DMEK in the same eye

Purpose:  To identify causes of reduced visual acuity after Descemet stripping (automated) endothelial keratoplasty (DSEK/DSAEK) and to determine whether such eyes can be successfully ‘repaired’ with a secondary Descemet membrane endothelial keratoplasty (DMEK).

Bowman Layer Transplantation to Reduce and Stabilize Progressive, Advanced Keratoconus

OBJECTIVE To evaluate the clinical outcome of mid-stromal isolated Bowman layer transplantation, a new surgical technique to reduce and stabilize ectasia in eyes with advanced keratoconus, to postpone penetrating keratoplasty or deep anterior lamellar keratoplasty, and to enable continued daily contact lens wear. DESIGN Prospective, nonrandomized cohort study at a tertiary referral center. PARTICIPANTS Twenty-two eyes of 19 patients with progressive, advanced keratoconus not eligible for ultraviolet cross-linking. INTERVENTIONS The mid-stroma was manually dissected and an isolated donor Bowman layer was positioned within the stromal pocket. MAIN OUTCOME MEASURES Before and up to 36 months after surgery (mean follow-up, 21±7 months), best spectacle-corrected visual acuity (BSCVA), best contact lens-corrected visual acuity (BCLVA), Scheimpflug-based corneal tomography measurements, endothelial cell density, biomicroscopy, refraction, and intraoperative and postoperative complications were recorded. RESULTS Two surgeries were complicated by an intraoperative perforation of Descemet membrane; no other intraoperative or postoperative complications were observed. Maximum keratometry decreased on average from 77.2±6.2 diopters (D) to 69.2±3.7 D (P < 0.001) at 1 month after surgery and remained stable thereafter (P ≥ 0.072). Mean BSCVA improved from 1.27±0.44 logarithm of the minimum angle of resolution units before surgery to 0.90±0.30 logarithm of the minimum angle of resolution units 12 months after surgery (P < 0.001), whereas BCLVA remained stable (P = 0.105). Mean thinnest-point pachymetry increased from 332±59 μm before surgery to 360±50 μm at the latest follow-up (P = 0.012), and no change in endothelial cell density was found (P = 0.355). CONCLUSIONS With isolated Bowman layer transplantation, reduction and stabilization of corneal ectasia was achieved in eyes with progressive, advanced keratoconus. Given the low risk for complications, the procedure may be performed to postpone penetrating or deep anterior lamellar keratoplasty.

Midstromal Isolated Bowman Layer Graft for Reduction of Advanced Keratoconus: A Technique to Postpone Penetrating or Deep Anterior Lamellar Keratoplasty

Midstromal implant of an isolated Bowman layer graft is a new approach to reduce ectasia in eyes with advanced keratoconus. The procedure should postpone penetrating or deep anterior lamellar keratoplasty. Ten eyes of 9 patients with progressive, advanced keratoconus and contact lens intolerance underwent the procedure with no intraoperative adverse events. Throughout the study period, we observed no complications related to stromal dissection and/or the Bowman layer graft. Maximum corneal power decreased from a mean (SD) of 74.5 (7.1) diopters (D) before to 68.3 (5.6) D after surgery (P = .002). Hence, implant of an isolated Bowman layer graft may offer a safe and effective new technique to reduce ectasia in eyes with advanced keratoconus, potentially allowing continued long-term contact lens wear. The low risk of complications may render the procedure suitable as a treatment to postpone penetrating or deep anterior lamellar keratoplasty in cases with impending contact lens intolerance and/or corneal scarring (clinicaltrials.gov Identifier: NCT01686906).