Two-Year Refractive Outcomes After Descemet Membrane Endothelial Keratoplasty

Accuracy of formulas for intraocular lens power for eyes undergoing descemet stripping automated endothelial keratoplasty and cataract surgery

BACKGROUND

To compare accuracy in intraocular lens (IOL) power calculation in eyes undergoing combined cataract and Descemet stripping and automated endothelial keratoplasty (C-DSAEK) surgery of the following formulas: Barrett Universal II, EVO, Haigis, Hoffer Q, Holladay 2, Kane and SRK/T.

METHODS

72 eyes from 72 patients (38 males, (53%)) with a mean age 68.08 ± 8.69 years (from 44 to 88 years old) underwent combined C-DSAEK were included. The IOL powers to implant were calculated with Barrett Universal II formula targeting -1 D refraction. Preoperative and postoperative data were used to obtain the median of absolute prediction errors (MAE) targeting emmetropia with every tested formula.

RESULTS

Means of MAE calculated were +1.45 D for Barrett Universal II, +1.37 D for EVO, +1.48 D for Haigis, +1.38 D for Hoffer Q, +1.37 D for Holladay 2, +1.39 D for Kane and +1.31 D for SRK/T. SRK/T MAE showed major significant (p < 0.01) differences compared to the other formulas.

DISCUSSION

Even if tested formulas are not able to accurately target emmetropia, SRK/T seems to be able to provide closer results in eyes undergoing C-DSAEK.

Comparison of Pre- and Post-DMEK Keratometry and Total Keratometry Values for IOL Power Calculations in Eyes Undergoing Triple DMEK

PURPOSE

To evaluate prediction accuracy of pre- and post-DMEK keratometry (K) and total keratometry (TK) values for IOL power calculations in Fuchs endothelial corneal dystrophy (FECD) eyes undergoing DMEK with cataract surgery (triple DMEK).

METHODS

Retrospective cross-sectional multicenter study of 55 FECD eyes (44 patients) that underwent triple DMEK between 2019 and 2022 between two centers in USA and Europe. Swept-source optical coherence tomography biometry (IOLMaster 700) was used for pre- and post-DMEK measurements. K and TK values were used for power calculations with ten formulae (Barrett Universal II (BUII), Castrop, Cooke K6, EVO 2.0, Haigis, Hoffer Q, Hoffer QST, Holladay I, Kane, and SRK/T). Mean error, mean absolute error (MAE), standard deviation, and percentage of eyes within ±0.50/±1.00 diopters (D) were calculated. Studied formulae were additionally adjusted using a method published previously (IOLup1D Method), which increases the IOL power by 1D. While both eyes from the same patient were considered for descriptive statistics, we restricted to one eye per individual (44 eyes for statistical comparisons.

RESULTS

MAEs for all formulae were lower for post-DMEK K and TK than pre-DMEK K and TK by an average of 0.24 and 0.47 D, respectively. The lowest MAE was 0.49 D for Kane using post-DMEK TK, and the highest MAE was 1.05 D for BUII using pre-DMEK TK. Most IOLup1D formulae had lower MAEs than pre-DMEK K and TK formulae.

CONCLUSIONS

The IOLup1D Method should be used instead of pre-DMEK K and TK values for triple DMEK in FECD eyes. Using post-DMEK TK values for cataract surgery after DMEK provides better refractive accuracy than any of the three studied methods used for triple DMEK procedures.

One-year Outcomes of Ultrathin Descemet Stripping Automated Endothelial Keratoplasty Combined with Cataract Surgery in the Korean Population

PURPOSE

To evaluate the refractive outcomes after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) combined with phacoemulsification and intraocular lens implantation (triple procedure) in the South Korean population.

METHODS

This retrospective observational study included 37 eyes of 36 patients who underwent the UT-DSAEK triple procedure between 2012 and 2021 in a single tertiary hospital. Preoperative and postoperative refractive outcomes and endothelial parameters at 1, 3, 6, and 12 months were observed.

RESULTS

At the final postoperative 12-month period, the average best-corrected visual acuity was 0.4 ± 0.5 in logarithm of the minimum angle of resolution. The mean endothelial cell density at 12 months was 1,841.92 ± 731.24 cells/mm2, indicating no significant endothelial cell loss compared to the baseline (p = 0.128). The mean postoperative central corneal thickness at 12 months was 597.41 ± 86.26 μm. The postoperative mean absolute error at 12 months was 0.96 ± 0.89 diopters (D) and mean error was 0.89 ± 0.97 D.

CONCLUSIONS

The results of our South Korean cohort study on UT-DSAEK triple surgery showed favorable and safe outcomes. Regardless of graft thickness, it should be noted that a hyperopic shift of 1.00 to 2.00 D needs to be considered in the case of UT-DSAEK triple surgery.

Excimer Laser Phototherapeutic Keratectomy for Anterior Corneal Opacification After Descemet Membrane Endothelial Keratoplasty

PURPOSE

The aim of this study was to assess the long-term outcome of excimer laser phototherapeutic keratectomy (PTK) for treating remaining anterior corneal opacities after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

This cohort study analyzed 67 eyes of 66 patients undergoing PTK in addition to and after DMEK between 2012 and 2021 at the Department of Ophthalmology, University of Cologne. Patients who were treated by PTK after previous DMEK on the same eye were included. The outcome parameters were best corrected visual acuity (BCVA), changes in refraction, endothelial cell density, corneal densitometry, central corneal thickness, and total corneal higher order aberrations. Patients with visual limitations in addition to anterior opacification were analyzed separately for their visual outcome. Eyes with severe visual limitations that have a very limited visual potential were excluded from the study. In addition, patients with not at least 1 postoperative follow-up examination were excluded from the study.

RESULTS

In this study, 67 eyes of 66 patients met all inclusion criteria. The median follow-up period was 13.1 (quartiles: 4.1; 30.7; interquartile range 26.6) months. The mean (±SD) BCVA improved from (logarithm of the minimum angle of resolution) 0.54 (±0.32) to 0.38 (±0.27) at the first postoperative visit ( P < 0.001) and remained significantly improved at all follow-up examinations compared with preoperative BCVA. Refraction and endothelial cell density did not change significantly after PTK. There was a significant decrease in corneal backscatter in the anterior corneal layer ( P < 0.001), and the total higher order aberration ( P = 0.02) and central corneal thickness were significantly reduced at the most recent postoperative visit ( P < 0.001). No immune reactions were observed.

CONCLUSIONS

Excimer laser PTK after DMEK for persisting anterior corneal opacities has the potential to significantly improve patients' vision without affecting refractive parameters or endothelial cell density.

Corneal densitometry patterns in Descemet membrane endothelial keratoplasty and Descemet stripping automated keratoplasty

PURPOSE

To compare corneal densitometry in a consecutive series of 52 endothelial keratoplasties (DMEK/DSAEK) using a Scheimpflug-based device after six months of follow-up.

METHODS

Corneal densitometry (CD) values of 102 eyes were divided into three main groups: 33 DMEKs, 19 DSAEKs, and 50 healthy eyes without previous ocular surgery. The CD values were then analyzed and compared between the groups. We measured three main layers in depth and four different concentric zones at 1, 3, and 6 months postoperatively.

RESULTS

In the DMEK group, total CD significantly decreased from 38.02 ± 10.21 grayscale units (GSU) to 31.13 ± 9.25 GSU (P < 0.01) between the first and the sixth month postoperative. In the DSAEK group, we found significant changes only between the first and three months after surgery (from 42.62 ± 9.31 GSU to 38.71 ± 10.53 GSU (P < 0.01). Regarding the concentric zones, CD in the DMEK group significantly decreased in the central zone from 33.55 ± 12.07 GSU to 30.63 ± 10.15 GSU (P < 0.01) and significantly increased in the periphery from 30.63 ± 10.15 GSU to 36.72 ± 9.37 GSU, (P < 0.01). The DSAEK group showed no changes in the central zone (from 36.91 ± 13.80 GSU to 36.14 ± 11.47 GSU, P = 0.52) and CD significantly increased in the periphery (41.91 ± 9.28 GSU, P < 0.01).

CONCLUSION

When comparing CD values in DMEK versus DSAEK, we found no differences by layers or at central-paracentral concentric zones, although CD differences in the peripheral zones were statistically significant. This finding may be attributed to the thicker graft at periphery with a delayed clearance and less anatomical interphase in DSAEK.

Descemet membrane endothelial keratoplasty combined with presbyopia-correcting and toric intraocular lenses - a narrative review

Fuchs endothelial corneal dystrophy (FECD) is the leading indication for EK and may coexist with cataract and presbyopia. Notably, the outcomes of phacoemulsification in FECD patients are not as favorable as those in eyes without this condition. Historically, only monofocal intraocular lenses (IOLs) were recommended for these patients. However, recent reports have described the implantation of Premium-IOLs (such as Multifocal IOLs, Enhanced Depth of Focus IOLs, and Toric IOLs) in FECD eyes undergoing cataract surgery and Descemet membrane endothelial keratoplasty (DMEK). While the results are encouraging, they are not as optimal as those from unoperated eyes, especially when comparing simultaneous procedures to sequential ones. It's advised to perform the DMEK first to improve the accuracy of IOL calculations. Still, even successfully operated eyes may experience secondary graft failure or graft rejection after DMEK. The success rate of a secondary DMEK is typically lower than that of the initial procedure. Furthermore, if the postoperative thickness after DMEK is less than anticipated, laser enhancements might not be an option. There's a pressing need for more controlled and randomized clinical trials to ascertain the safety and effectiveness of Premium-IOLs for FECD eyes. This narrative review aims to collate evidence on the use of Premium IOL technologies in eyes receiving EK and to underscore key points for surgeons performing EK combined with cataract surgery.

Refractive outcomes after DMEK: meta-analysis

In this meta-analysis and systematic literature review of refractive outcomes after Descemet membrane endothelial keratoplasty (DMEK), the extent of the refractive shift and an overview of reasons for refractive shift after DMEK are provided. The PubMed library was screened for articles containing the terms "Descemet membrane endothelial keratoplasty," "DMEK," "Descemet membrane endothelial keratoplasty combined with cataract surgery," "triple-DMEK" combined with "refractive outcomes," "refractive shift," and "hyperopic shift." The refractive outcomes after DMEK were analyzed and compared using a fixed and random effects model. The overall mean change of the spherical equivalent outcome when compared with the preoperative value in cases of DMEK or when compared with the preoperative target refraction in cases of DMEK combined with cataract surgery was +0.43 diopters (D) (95% CI, 0.31-0.55). When DMEK is combined with cataract surgery, a target refraction of -0.5 D is recommended to achieve emmetropia. Changes in the posterior corneal curvature are identified as the main cause of the refractive hyperopic shift.

Impact of Fuchs Endothelial Corneal Dystrophy Severity on Scheimpflug-Derived Parameters After Descemet Membrane Endothelial Keratoplasty

PURPOSE

The aim of this study was to evaluate how Scheimpflug-derived parameters of eyes with Fuchs endothelial corneal dystrophy (FECD) are influenced by Descemet membrane endothelial keratoplasty (DMEK) depending on FECD severity and the presence of subclinical edema.

METHODS

A retrospective cohort study including 115 eyes (115 patients) that underwent DMEK for FECD and a control group of 27 eyes with nonpathological corneas was conducted. Preoperative and 6 months postoperative Scheimpflug imaging was used to analyze pachymetry, presence of tomographic features (loss of isopachs/displacement of the thinnest point/focal posterior depression), and corneal backscatter. FECD severity was based on the modified Krachmer scale and the absence/presence of subclinical edema.

RESULTS

Scheimpflug-derived pachymetry, tomographic, and corneal backscatter parameters were correlated with FECD severity, and all changed from preoperatively to postoperatively (all P < 0.05). Postoperative central corneal thickness, anterior and posterior corneal backscatter, and presence of focal posterior depression remained different from the control group (all P < 0.05). Of eyes without preoperative clinical edema (n = 75), 18.7% showed 0 or 1 tomographic feature (no edema group) and 82.4% had 2 or 3 features (subclinical edema group). Compared with the control group, postoperative best-corrected visual acuity for the "no edema" group did not differ (0.03 ± 0.12 vs. -0.02 ± 0.08 logarithm of the minimum angle of resolution, P = 0.150) but was worse for the subclinical edema group (0.06 ± 0.08 vs. -0.02 ± 0.08 logarithm of the minimum angle of resolution, P = 0.001).

CONCLUSIONS

For eyes without preoperative edema, more parameters reversed back to 'normal' levels than for eyes with (sub)clinical edema. Although most analyzed parameters correlated with FECD severity, corneal tomography might be best suited for objective grading of disease severity to aid in surgical decision-making.

Descemet Membrane Endothelial Keratoplasty-Induced Refractive Shift and Descemet Membrane Endothelial Keratoplasty-Induced Intraocular Lens Calculation Error

PURPOSE

The aim of this study was to determine the mechanisms leading to the refractive shift and intraocular lens calculation error induced by Descemet membrane endothelial keratoplasty (DMEK), using ocular biometry and corneal elevation tomography data.

METHODS

This is a retrospective, monocentric cohort study. Eyes which underwent uncomplicated DMEK surgery with available pre-DMEK and post-DMEK Scheimpflug rotating camera data (Pentacam, Oculus, Wetzlar, Germany) were considered for inclusion with an age-matched control group of healthy corneas. Cataract surgery data were collected for triple-DMEK cases. DMEK-induced refractive shift (DIRS) and intraocular lens calculation error (DICE) were calculated. Pearson r correlation coefficient was calculated between each corneal parameter variation and both DIRS and DICE.

RESULTS

DIRS was calculable for 49 eyes from 43 patients. It was 30.61% neutral, 53.06% hyperopic (36.73% > 1D), and 16.32% myopic (6.12% > 1 D). DICE was calculable for 30 eyes of 26 patients: It was 46.67% neutral, 40.00% hyperopic (10.00% > 1D), and 13.33% myopic (3.33% > 1D). DIRS and DICE were mainly associated with variations in PRC/ARC ratio, anterior average radii of curvature (ARC), posterior average radii of curvature (PRC), and posterior Q.

CONCLUSIONS

Our results suggest that ARC variations, PRC/ARC ratio variations, PRC variations, and posterior Q variations are the most influential parameters for both DIRS and DICE. We suggest that a distinction between those different phenomenons, both currently described as "hyperopic shift" in the literature, should be made by researchers and clinicians.

Clinical Outcomes of Descemet's Membrane Endothelial Keratoplasty without Routine Prophylactic Peripheral Iridotomy

Objectives: To analyze the outcomes and complications of Descemet's membrane endothelial keratoplasty (DMEK) performed without prophylactic peripheral iridotomy (PI). Methods: Design: Retrospective study.

SETTING

Institutional, tertiary care eye hospital.

STUDY POPULATION

All patients who underwent DMEK or DMEK combined with phacoemulsification (DMEK triple) for Fuchs endothelial dystrophy, using a standardized protocol between August 2016 and July 2021, were included. Previous glaucoma surgery, laser PI, aphakia, or complicated pseudophakia were excluded.

MAIN OUTCOME MEASURES

Primary outcomes: Incidence of pupillary block (PB).

SECONDARY OUTCOMES

Graft detachment (GD), rebubbling rates, uncorrected (UCDVA) and best corrected logMAR distance visual acuity (BCDVA), and endothelial cell loss (ECL) at six months. Data were analyzed using the chi-square test and stepwise backward regression analysis. Results: 104 eyes of 72 patients were included. Four eyes (3.8%) developed PB; in two of these cases, standard protocol was not followed. Overall minor GD occurred in 43.2% (n = 45); significant GD was present only in 7 eyes (6.6%). Overall slit lamp rebubbling rate was 30% (n = 35), though only four patients were rebubbled in theatre (3.8%). PB, GD, and rebubbling rates did not vary with the surgeon, surgery, or tamponade (air or SF6 gas). UCDVA, BCDVA, and ECL at 6 months were 0.29 ± 0.31, 0.20 ± 0.28, and 40.46 ± 20.36%, respectively. Conclusions: Compared to previously reported outcomes of DMEK with PI, our results of PI less DMEK using a standardized protocol have a similar incidence of pupillary block, graft detachment, and rebubbling, with comparable visual acuity and endothelial cell loss.

Standard vs total keratometry for intraocular lens power calculation in cataract surgery combined with DMEK

PURPOSE

To compare the prediction accuracy of standard keratometry (K) and total keratometry (TK) for intraocular lens (IOL) power calculation in eyes undergoing combined cataract surgery and Descemet membrane endothelial keratoplasty (triple DMEK).

SETTING

Tertiary care academic referral center.

DESIGN

Retrospective case series.

METHODS

Review of 83 eyes (63 patients) that underwent triple DMEK between 2019 and 2021. Biometry measurements were obtained using a swept-source optical biometer (IOLMaster 700). 63 eyes were used for statistical analysis. Mean error, mean absolute error (MAE), SD, median absolute error, maximum absolute error, root mean squared prediction error, and the percentage of eyes within prediction errors of ±0.50 diopters (D) and ±1.00 D were calculated for 9 multivariate and third-generation formulas using K and TK values (Barrett Universal II, Yeo EVO 2.0, Cooke K6, Kane, Pearl-DGS, Haigis, Holladay 1, Hoffer Q, and SRK/T). Formulas were additionally tested by using the prediction for an IOL power 1 D below the IOL used (IOLup1D).

RESULTS

For all formulas, MAE was lower for K than for TK by an average of 0.21 D. The lowest MAE value observed was 0.67 D for "adjusted" SRK/T using K, and the highest MAE values observed were 1.24 D and 1.24 D for nonadjusted Hoffer Q and Haigis using TK, respectively. Overall, lower MAE values were observed for multivariate formulas and SRK/T.

CONCLUSIONS

In triple DMEK eyes, the prediction accuracy of K was higher than that of TK. The most accurate formulas were SRK/T and multivariate formulas using K with the IOLup1D adjustment.

Changes in Corneal Power up to 2 Years After Endothelial Keratoplasty: Results From the Randomized Controlled Descemet Endothelial Thickness Comparison Trial

PURPOSE

To compare changes in corneal power measurements after Descemet membrane endothelial keratoplasty (DMEK) vs ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK).

DESIGN

Post hoc subanalysis of the randomized controlled Descemet Endothelial Thickness Comparison Trial.

METHODS

A total of 50 eyes (38 patients) with endothelial dysfunction from Fuchs' endothelial dystrophy or pseudophakic bullous keratopathy were randomized to DMEK or UT-DSAEK 1 to 2 days before surgery. Total corneal refractive power (TCRP) and anterior/posterior simulated keratometry were obtained using Scheimpflug imaging preoperatively (baseline) and postoperatively at 3, 6, 12, and 24 months. Spectacle refractions were performed at 6, 12, and 24 months after surgery.

SETTING

Hospital centers.

RESULTS

The mean hyperopic shift of TCRP from baseline to 12 months was 0.80 ± 1.1 (P = .002) in the DMEK group and 0.69 ± 0.84 (P < .001) in the UT-DSAEK group. Posterior corneal curvature (average K from simulated keratometry) steepened (more negative dioptric power) by 0.42 ± 0.10 (P < .001) in DMEK and 0.54 ± 0.09 (P < .001) in UT-DSAEK. The mean change in TCRP and posterior corneal curvature did not differ between DMEK and UT-DSAEK (TCRP, P = .71; posterior average K from simulated keratometry, P = .36).

CONCLUSIONS

Sustained steepening in posterior corneal curvature with loss in total corneal power contributes to hyperopic shifts after endothelial keratoplasty. Changes in corneal measurements do not differ between DMEK and UT-DSAEK. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

IOL Power Calculation in Eyes Undergoing Combined Descemet Membrane Endothelial Keratoplasty and Cataract Surgery

PURPOSE

To assess the accuracy of different corneal powers for intraocular (IOL) power calculation in combined Descemet membrane endothelial keratoplasty (DMEK) and cataract surgery and investigate whether preoperative parameters correlate to the prediction error (PE).

METHODS

This prospective case series involved patients with Fuchs endothelial dystrophy receiving combined DMEK and cataract surgery. Preoperatively, patients underwent optical biometry and anterior segment OCT (AS-OCT). AS-OCT measurements were repeated 6 months postoperatively, when final refraction was assessed. The PE was calculated using the preoperative average keratometry (K_ave) measured by the optical biometer and User Group for Laser Interference Biometry (ULIB) constants. It was also calculated, after constant optimization, using the preoperative K_ave from both devices and the total corneal power (TCP) measured by AS-OCT, as well as the postoperative K_ave and TCP measured by AS-OCT.

RESULTS

ULIB constants resulted in the highest hyperopic PE (P < .0001). Constant optimization improved the results, because the PE was zeroed out and the absolute PEs decreased. No significant difference was found among the Barrett Universal II, Emmetropia Verifying Optical 2.0, Haigis, Hoffer Q, Holladay 1, Kane, and SRK/T formulas. Further improvement was achieved with the postoperative K_ave and TCP, although the accuracy remained moderate. The PE based on preoperative corneal measurements was correlated to the amount of corneal flattening; the latter could be predicted by multiple linear regression accounting for anterior and posterior corneal radii (P = .0002) and was correlated to the preoperative anterior/posterior ratio.

CONCLUSIONS

Constant optimization is beneficial for combined DMEK and phacoemulsification. Predicting postoperative corneal flattening may improve the results of IOL power accuracy. [J Refract Surg. 2022;38(7):435-442.].

“Endothelium-Out” and “Endothelium-In” Descemet Membrane Endothelial Keratoplasty (DMEK) Graft Insertion Techniques: A Systematic Review With Meta-Analysis

Background

We evaluated the visual outcomes and complications of “endothelium-out” and “endothelium-in” Descemet membrane endothelial keratoplasty (DMEK) graft insertion techniques.

Materials and Methods

Electronic searches were conducted in CENTRAL, Cochrane databases, PubMed, EMBASE, ClinicalTrials.gov. Study designs included clinical trials, comparative observational studies, and large case series (≥25 eyes). PRISMA guidelines were used for abstracting data and synthesis. Random-effects models were employed for meta-analyses.

Results

21,323 eyes (95 studies) were included. Eighty-six studies reported on “endothelium-out” techniques; eight studies reported on “endothelium-in” techniques. One study compared “endothelium-out” to “endothelium-in” techniques. Eighteen “endothelium-out” studies reported that 42.5–85% of eyes achieved best-corrected visual acuity (BCVA) ≥20/25 at 6 months; pooled proportion of eyes achieving BCVA ≥20/25 at 6 months was 58.7% (95% CI 49.4–67.7%,15 studies). Three “endothelium-in” studies reported that 44.7–87.5% of eyes achieved BCVA of ≥20/25 at 6 months; pooled proportion of eyes achieving BCVA ≥20/25 at 6 months was 62.4% (95% CI 33.9–86.9%). Pooled mean endothelial cell loss was lower in the “endothelium-in” studies (28.1 ± 1.3%, 7 studies) compared to “endothelium-out” studies (36.3 ± 6.9%,10 studies) at 6 months (p = 0.018). Graft re-bubbling rates were higher in the “endothelium-out” studies (26.2%, 95% CI 21.9–30.9%, 74 studies) compared to “endothelium-in” studies (16.5%, 95% CI 8.5–26.4%, 6 studies), although statistical significance was not reached (p = 0.440). Primary graft failure rates were comparable between the two groups (p = 0.552). Quality of evidence was considered low and significant heterogeneity existed amongst the studies.

Conclusion

Reported rates of endothelial cell loss were lower in “endothelium-in” DMEK studies at 6 months compared to “endothelium-out” studies. Outcomes of “endothelium-in” techniques were otherwise comparable to those reported in “endothelium-out” studies. Given the technical challenges encountered in “endothelium-out” procedures, surgeons may consider “endothelium-in” techniques designed for easier intra-operative DMEK graft unfolding. “Endothelium-in” studies evaluating outcomes at longer time points are required before conclusive comparisons between the two techniques can be drawn.

Effects of Combined Cataract Surgery on Outcomes of Descemet's Membrane Endothelial Keratoplasty: A Systematic Review and Meta-Analysis

Objective

A systematic review and meta-analysis of literature-to-date regarding the effects of combined cataract surgery on outcomes of DMEK.

Methods

Multiple electronic databases were searched, including Cochrane Library databases, PubMed, Web of Science, and ClinicalTrials.gov. The final search was updated on 10th February 2022. We included randomized controlled trials (RCTs), non-randomized studies and large case series (≥25 eyes) of DMEK (pseudophakic/phakic) and “triple DMEK”. A total of 36 studies were included in this study. Meta-analyses were done with risk differences (RD) computed for dichotomous data and the mean difference (MD) for continuous data via random-effects model. Primary outcome measure: postoperative re-bubbling rate; secondary outcome measures: complete/partial graft detachment rate, best-corrected visual acuity (BCVA), endothelial cell loss (ECL), primary graft failure, and cystoid macular edema (CMO).

Results

A total of 11,401 eyes were included in this review. Based on non-randomized studies, triple DMEK demonstrated a better BCVA at 1-month postoperative than DMEK alone (MD 0.10 logMAR; 95% CI: 0.07–0.13; p < 0.001), though not statistically significant at 3–6 months postoperative (MD 0.07 logMAR; 95% CI: −0.01 to 0.15; p = 0.08). There was no significant difference in rebubbling, ECL, graft failures, and CMO postoperatively between the two groups (p = 0.07, p = 0.40, 0.06, and 0.54 respectively).

Conclusion

Our review suggests that DMEK has a similar post-operative complication risk compared to “triple DMEK” (low-quality evidence), with comparable visual outcome and graft survival rate at 6 months postoperative. High-quality RCTs specifically studying the outcomes of combined vs. staged DMEK are still warranted.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020173760, identifier: CRD42020173760.

Photorefractive keratectomy after DMEK for corneal decompensation by phakic IOL

PURPOSE

To provide the first description of photorefractive keratectomy (PRK) for the correction of mild residual refractive error after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Case report.

RESULTS

A 45 year-old woman presenting with phakic intraocular lens (PIOL)-related corneal decompensation underwent staged DMEK surgery following PIOL explantation and cataract surgery. Eighteen months after DMEK, uncorrected distance visual acuity (UDVA) was 20/60 and best-corrected visual acuity (BCVA) was 20/22, with a stable refraction. The patient requested refractive surgery to decrease spectacle dependance, and wavefront-optimized PRK was performed. At last follow-up observation thirty-three months after PRK (54 months after DMEK surgery), UDVA was 20/20, the cornea remained clear without signs of rejection or endothelial failure, and the endothelial cell loss rate was not accelerated after PRK.

CONCLUSION

Since long-term visual and refractive stability can be expected after DMEK, PRK may be a particular safe and effective approach for the correction of mild residual refractive errors after DMEK. However, we consider that surgeons must exercise caution when considering keratorefractive surgery in these eyes due to postoperative changes in corneal curvature and thickness, and further studies are encouraged.

Corneal Densitometry After Uneventful Descemet Membrane Endothelial Keratoplasty-5-Year Outcomes

PURPOSE

The purpose of this study is to analyze the course of corneal densitometry (CD), endothelial cell density (ECD), best-corrected visual acuity (BCVA), and central corneal thickness (CCT) 5 years after uneventful Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Sixty uneventful cases (51 patients) with a minimum follow-up of 5 years were included. CD of various corneal layers (anterior, central, posterior, and total layer) and zones (0-2 mm, 2-6 mm, and 6-10 mm) were measured with Scheimpflug tomography. ECD, BCVA, and CCT were also evaluated.

RESULTS

Total CD at 0 to 2 mm and 2 to 6 mm zones significantly decreased from 33 ± 10 and 27.8 ± 8 grayscale units (GSU) preoperatively to 21.8 ± 3.1 and 22.2 ± 4.2 GSU at 5 years, respectively (P < 0.001). On the contrary, total CD at the 6 to 10 mm zone significantly increased from 30 ± 8.3 GSU preoperatively to 34.6 ± 7.8 GSU at 5 years (P < 0.001). ECD significantly decreased from 2496 ± 267 cells/mm2 preoperatively to 1063 ± 470 cells/mm2 at 5 years (P < 0.001). Similarly, CCT significantly decreased from 686 ± 109 μm preoperatively to 557 ± 37 μm at 5 years (P < 0.001). Postoperative BCVA was significantly better after DMEK for every examination time point.

CONCLUSIONS

Despite a slight CD increase at all layers of all corneal zones from the second to the fifth postoperative year, the excellent visual outcome was maintained throughout 5-year follow-up. Thus, DMEK seems to effectively treat corneal endothelial disease in the long term.

Region of Interest Densitometry Analysis of Descemet Membrane Endothelial Keratoplasty Dehiscence on Anterior Segment Optical Coherence Tomography

Purpose

To evaluate a region of interest (ROI) method of analyzing anterior segment optical coherence tomography (AS-OCT) corneal densitometry (CD) in the setting of Descemet membrane endothelial keratoplasty (DMEK) dehiscence.

Methods

Retrospective chart review of eyes that underwent (1) DMEK for Fuchs dystrophy (2) between 2018 to 2020 with (3) a partial DMEK dehiscence on AS-OCT, (4) involvement of only one side of the graft, (5) high-quality corneal AS-OCT scan, and (6) location of dehiscence within the central 5.5 mm of the cornea. Image analysis of the ROIs with ImageJ compared the total edematous area, mean stromal CD, and ratio of anterior-to-posterior (A/P) stromal CD for regions of DMEK dehiscence compared to the contralateral side with an attached DMEK graft. Control regions (with no dehiscence) and postdehiscence resolution images were also analyzed.

Results

Seventy sectors of the 21 images from 21 eyes with DMEK dehiscence were included. Compared to the contralateral side, regions of DMEK dehiscence had larger total areas (P < 0.0001), lower mean stromal CD (P = 0.0003), and higher A/P stromal CD (P < 0.0001). All control regions and postdehiscence resolution images did not show any significant differences compared to the contralateral sides.

Conclusions

This technique to analyze multiple ROIs on AS-OCT can be useful to evaluate CD of specific regions of corneal pathology. Lower mean stromal CD and higher A/P stromal CD may specify corneal edema.

Translational Relevance

Analyzing CD via multiple specific ROIs may be more suitable than measuring the CD of the full cornea and has broader applications extending to other corneal pathologies.

Refractive Outcomes in Fuchs' Endothelial Corneal Dystrophy: Conventional and Femtosecond Laser-Assisted Cataract Surgery

Purpose

To investigate the refractive outcomes of eyes with Fuchs’ endothelial corneal dystrophy (FECD) following phacoemulsification.

Methods

This is a retrospective chart review of patients with FECD who underwent phacoemulsification. Manifest refraction at the early postoperative period (1–6 weeks) and late postoperative period (3–12 months) was collected. The spherical equivalent (SE) and variance of SE from target in diopters (D) were analyzed.

Results

A total of 219 eyes from 175 FECD patients (73 FLACS, 146 conventional phacoemulsification) were included. In the early postoperative period, when comparing variance from intended target, 62% (n=126) had a SE variance of ≤0.5 D, 22% (n=44) >0.5 D and ≤1 D, and 17% (n=34) >1 D. In the late postoperative period, 62% (n=85) had a SE variance of ≤0.5 D, 19% (n=26) >0.5 D and ≤1 D, and 20% (n=27) >1 D. There was no difference in the variance of SE comparing FLACS versus conventional phacoemulsification in either the early postoperative period (p=0.78) or the late postoperative period (p=0.29).

Conclusion

Patients with mild-to-moderate FECD had favorable refractive outcomes with phacoemulsification. There was no difference in refractive outcomes in eyes with FECD between the group that underwent FLACS versus the group that underwent conventional phacoemulsification.

Refractive outcome and tomographic changes after Descemet membrane endothelial keratoplasty in pseudophakic eyes with Fuchs' endothelial dystrophy

Purpose

To analyze refractive and topographic changes secondary to Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic eyes with Fuchs’ endothelial dystrophy (FED).

Methods

Eighty-seven pseudophakic eyes of 74 patients who underwent subsequent DMEK surgery for corneal endothelial decompensation and associated visual impairment were included. Median post-operative follow-up time was 12 months (range: 3–26 months). Main outcome measures were pre- and post-operative manifest refraction, anterior and posterior corneal astigmatism, simulated keratometry (CA_SimK) and Q value obtained by Scheimpflug imaging. Secondary outcome measures included corrected distance visual acuity (CDVA), central corneal densitometry, central corneal thickness, corneal volume (CV), anterior chamber volume (ACV) and anterior chamber depth (ACD).

Results

After DMEK surgery, mean pre-operative spherical equivalent (± SD) changed from + 0.04 ± 1.73 D to + 0.37 ± 1.30 D post-operatively (p = 0.06). CDVA, proportion of emmetropic eyes, ACV and ACD increased significantly during follow-up. There was also a significant decrease in posterior corneal astigmatism, central corneal densitometry, central corneal thickness and corneal volume over time (p = 0.001). Only anterior corneal astigmatism and simulated keratometry (CA_SimK) remained fairly stable after DMEK.

Conclusion

Despite tendencies toward a hyperopic shift, changes in SE were not significant and refraction remained overall stable in pseudophakic patients undergoing DMEK for FED. Analysis of corneal parameters by Scheimpflug imaging mainly revealed changes in posterior corneal astigmatism pointing out the relevance of posterior corneal profile changes during edema resolution after DMEK.

Comparing corneal outcome between femtosecond laser-assisted cataract surgery and conventional phaco surgery in Fuchs' endothelial dystrophy patients: a randomized pilot study with 6mo follow up

AIM

To compare the corneal outcome in Fuchs' endothelial dystrophy (FED) patients between femtosecond laser-assisted cataract surgery (FLACS) and conventional phaco surgery (CPS).

METHODS

This was a randomized controlled study comparing one eye surgery by FLACS and the contralateral eye operated by CPS (stop and chop technique) in FED patients. Central corneal thickness, corneal light backscatter, corneal densitometry, and central corneal endothelial cell count and hexagonality (noncontact endothelial cell microscope), and corrected distance visual acuity (CDVA) were assessed preoperatively and at day 1, 40, and 180 postoperatively.

RESULTS

Totally 31 patients (16 women) were included. At day 40 postoperatively, the mean endothelial cell loss (ECL) was 23.67% by FLACS and 17.30% by CPS (P=0.53). At day 180 postoperatively, ECL was 25.58% in FLACS and 21.32% in CPS (P=0.69). Densitometry data in all layers and all annuli from anterior layer to posterior layer in annuli 0-2, 2-6, 6-10 and 10-12, total densitometry with all layers and all annuli was performed. A significant difference was found in 6-10 (posterior layer) at day 1 with -1.42 grayscale units (GSU; 95%CI: -2.66 to -0.19, P=0.02). In 10-12 (anterior layer, central layer and all layers) at day 40 were significant different with 7.7 (95%CI: 1.89 to 13.50, P=0.009), 3.97 (95%CI: 0.23 to 7.71, P=0.03), 4.73 GSU (95%CI: 0.71 to 8.75, P=0.02), respectively. In the remaining parameters we found no difference between the two groups (P>0.05). Three CPS eyes suffered from corneal decompensation.

CONCLUSION

There is no significant difference in corneal outcome between FLACS and CPS. Endothelial cell density and pentacam corneal outcome may be inadequate as outcome parameters in FED patients.

Refractive accuracy in eyes undergoing combined cataract extraction and Descemet membrane endothelial keratoplasty

PURPOSE

To evaluate the refractive accuracy of current intraocular lens (IOL) formulas and propose a modification in calculation of corneal power in eyes undergoing combined cataract extraction and Descemet membrane endothelial keratoplasty (DMEK).

DESIGN

Retrospective cohort study.

METHODS

Patients with Fuchs endothelial corneal dystrophy undergoing uncomplicated combined cataract surgery and DMEK at a single institution were included. The Hoffer Q, SRK/T, Holladay I, Barrett Universal II and Haigis formulas were compared. A modified corneal power was calculated using a thick lens equation based on anterior and posterior corneal radii and corneal thickness from Pentacam imaging. Error calculations were adjusted based on the difference in optical biometry and the modified corneal power. Mean absolute error (MAE) for each formula was compared between the corneal power modification and optical biometry corneal power.

RESULTS

In 86 eyes, the mean error ranged from 0.90 D for the Barrett Universal II formula to -0.10 D for the Haigis formula, with 4 of 5 formulas resulting in a mean hyperopic error. The corneal power modification resulted in a significantly lower MAE for the Hoffer Q (0.82 D), Holladay I (0.85 D), SRK/T (0.85 D) and Barrett Universal II (0.90 D) formulas compared with optical biometry corneal power for the Hoffer Q (1.02 D; p<0.005), Holladay I (0.97 D; p<0.005), SRK/T (0.93 D; p<0.01) and Barrett Universal II (1.16 D; p<0.005) formulas.

CONCLUSIONS

All formulas except the Haigis formula resulted in a hyperopic error. The corneal power modification significantly reduced error in four out of five IOL formulas.

Assessing the validity of corneal power estimation using conventional keratometry for intraocular lens power calculation in eyes with Fuch's dystrophy undergoing Descemet membrane endothelial keratoplasty

PURPOSE

The present retrospective study was designed to test the hypothesis that the postoperative posterior to preoperative anterior corneal curvature radii (PPPA) ratio in eyes with Fuch's dystrophy undergoing Descemet membrane endothelial keratoplasty (DMEK) is significantly different to the posterior to anterior corneal curvature radii (PA) ratio in virgin eyes and therefore renders conventional keratometry (K) and the corneal power derived by it invalid for intraocular lens (IOL) power calculation.

METHODS

Measurement of corneal parameters was performed using Scheimpflug imaging (Pentacam HR, Oculus, Germany). In 125 eyes with Fuch's dystrophy undergoing DMEK, a fictitious keratometer index was calculated based on the PPPA ratio. The preoperative and postoperative keratometer indices and PA ratios were also determined. Results were compared to those obtained in a control group consisting of 125 eyes without corneal pathologies. Calculated mean ratios and keratometer indices were then used to convert the anterior corneal radius in each eye before DMEK to postoperative posterior and total corneal power. To assess the most appropriate ratio and keratometer index, predicted and measured powers were compared using Bland-Altman plots.

RESULTS

The PPPA ratio determined in eyes with Fuch's dystrophy undergoing DMEK was significantly different (P < 0.001) to the PA ratio in eyes without corneal pathologies. Using the mean PA ratio (0.822) and keratometer index (1.3283), calculated with the control group data to convert the anterior corneal radius before DMEK to power, leads to a significant (P < 0.001) underestimation of postoperative posterior negative corneal power (mean difference (∆ = - 0.14D ± 0.30) and overestimation of total corneal power (∆ = - 0.45D ± 1.08). The lowest prediction errors were found using the geometric mean PPPA ratio (0.806) and corresponding keratometer index (1.3273) to predict the postoperative posterior (∆ = - 0.01 ± 0.30) and total corneal powers (∆ = - 0.32D ± 1.08).

CONCLUSIONS

Corneal power estimation using conventional K for IOL power calculation is invalid in eyes with Fuch's dystrophy undergoing DMEK. To avoid an overestimation of corneal power and minimize the risk of a postoperative hyperopic shift, conventional K for IOL power calculation should be adjusted in eyes with Fuch's dystrophy undergoing cataract surgery combined with DMEK. The fictitious PPPA ratio and keratometer index may guide further IOL power calculation methods to achieve this.

Refractive Outcomes After Descemet Membrane Endothelial Keratoplasty + Cataract/Intraocular Lens Triple Procedure: A Fellow Eye Comparison

PURPOSE

Descemet membrane endothelial keratoplasty is often combined with phacoemulsification and intraocular lens implantation (DMEK + cataract/IOL triple procedure) in phakic patients. This procedure results in a refractive shift that is difficult to predict. The aim of this study was to evaluate the hypothesis that the refractive shift in the second eye follows the shift in the first eye.

METHODS

In this retrospective, single-center, consecutive case series, the refractive outcomes of 254 eyes of 127 patients who underwent DMEK + cataract/IOL triple procedure in both eyes for Fuchs endothelial corneal dystrophy have been analyzed. Main outcome measures were spherical equivalent outcome (shift calculations), best spectacle-corrected visual acuity, central corneal thickness, and posterior simulated keratometry.

RESULTS

The mean best spectacle-corrected visual acuity before surgery was 0.51 ± 0.24 and increased to 0.19 ± 0.15 (logMAR) after surgery (P < 0.001). After surgery, a mean hyperopic shift of 0.98 ± 0.89 D was observed. The refractive shift was 1.03 ± 0.93 D and 0.92 ± 1.02 D, in the first and second eyes, respectively (P = 0.435). In a paired analysis, the mean difference of the refractive shift between the first and second eyes was 0.49 ± 0.43 D.

CONCLUSIONS

In our fellow eye comparison, the refractive shift after DMEK + cataract/IOL triple procedure in the second eye was comparable with the shift in the first eye. As a consequence, the refractive outcome of the first eye might serve as a reference for optimizing the refractive target in the second eye. Further studies investigating the influence of corneal parameters on refractive shift are needed for a more predictable lens power selection.

Refractive Outcomes of Descemet Membrane Endothelial Keratoplasty Combined With Cataract Surgery in Fuchs Endothelial Dystrophy

PURPOSE

To evaluate the refractive outcomes of Descemet membrane endothelial keratoplasty combined with cataract surgery (DMEK triple) in patients with Fuchs endothelial dystrophy.

METHODS

A retrospective analysis of 68 eyes of 68 patients with Fuchs endothelial dystrophy who underwent DMEK triple between 2014 and 2018.

RESULTS

The mean age of patients was 66.5 ± 8.6 years, and 65% (44 of 68) were female. Mean target refraction was -0.69 diopters (D) (interquartile range: -0.80 to -0.50 D). At 6 months, 47% (32 of 68) and 63% (43 of 68) of eyes were within ±0.50 and ±1.00 D of target refraction, respectively. Among eyes greater than 0.50 D from target, 78% (28 of 36) were hyperopic surprises. Mean spherical equivalent at 6 months was -0.14 ± 1.26 D, representing a mean hyperopic shift of 0.55 D from target. Preoperative pachymetry was higher in eyes with greater than 0.50 D of hyperopic surprise (648 ± 60 vs 613 ± 49 µm, P = .04). Refractive shift was greater in eyes with a preoperative central corneal thickness of 640 µm or greater versus eyes with a central corneal thickness of less than 640 µm (+1.20 ± 0.92 vs +0.40 ± 0.99 D, P = .02). None of the eyes with a preoperative central corneal thickness of 640 µm or greater shifted myopically compared to target (range: -0.09 to +2.89 D).

CONCLUSIONS

A mean hyperopic shift of 0.55 D from target refraction occurred after DMEK triple, and 47% of eyes were within 0.50 D of target refraction at 6 months postoperatively. Thicker corneas preoperatively had greater hyperopic shift. A greater myopic target refraction may be warranted in eyes with a preoperative central corneal thickness of 640 µm or greater. [J Refract Surg. 2020;36(10):661-666.].

Anatomical Changes in the Anterior Chamber Volume After Descemet Membrane Endothelial Keratoplasty

PURPOSE

To evaluate changes in the anterior chamber of eyes that have undergone Descemet membrane endothelial keratoplasty (DMEK) and to identify factors that affect these changes.

METHODS

This retrospective study included 25 pseudophakic eyes of 25 patients who underwent DMEK. We determined the preoperative and postoperative values of the best spectacle-corrected visual acuity, spherical equivalent (SE), anterior chamber volume (ACV), anterior chamber depth (ACD), central corneal thickness (CCT), and scleral spur angle (SSA) evaluated using anterior segment optical coherence tomography and iris damage score and iris posterior synechiae score. We defined ∆ as the average change rate from the preoperative to postoperative value for each factor at 1 month (SE at 6-12 months) postoperatively. We also analyzed correlations between ∆ACV, ∆SE, and other preexisting factors.

RESULTS

Compared with the preoperative ACV value (128 ± 28 mm3), the postoperative value significantly increased to 155 ± 21 mm3 (P < 0.001); ∆SE was +1.01 ± 1.09 diopters. ∆ACV was negatively correlated with preoperative ACD (R = 0.643, P < 0.001) and SSA (R = 0.555, P = 0.001) and positively correlated with ∆ACD (R = 0.799, P < 0.001) and ∆SSA (R = 0.608, P < 0.001). ∆CCT, iris damage score, and iris posterior synechiae score were not significantly correlated with ∆ACV. ∆SE was positively correlated with ∆ACV, ∆ACD, and ∆SSA (R = 0.680, 0.455, and 0.478; P < 0.001, <0.05, and <0.05, respectively).

CONCLUSIONS

An increase in the ACV and hyperopic change was noted after successful DMEK, especially in eyes with narrow-angled shallow anterior chambers.

Endothelial Cell Loss After Descemet's Membrane Endothelial Keratoplasty for Fuchs' Endothelial Dystrophy: DMEK Compared to Triple DMEK

PURPOSE

This study compared the outcomes after Descemet's membrane endothelial keratoplasty (DMEK) in pseudophakic patients with the outcomes after DMEK combined with cataract surgery (triple-DMEK) in patients with Fuchs' endothelial dystrophy (FED).

DESIGN

Retrospective, single-institution, interventional, consecutive case series.

METHODS

Outcomes of 114 DMEKs in patients with FED at a minimum of 1-year follow-up were reviewed. A total of 34 eyes (29 patients) were pseudophakic and underwent only DMEK (DMEK-only), and 80 eyes (56 patients) underwent triple-DMEK. Main outcome measurements included endothelial cell loss (ECL), best-corrected visual acuity (BCVA), central corneal thickness (CCT), and complications.

RESULTS

At 1 month, ECL was 25% (±16%) and 35% (±15%) in DMEK-only and triple-DMEK groups, respectively. At 1 year, ECL was 33% (±13%) and 41% (±16%) in DMEK-only and triple-DMEK groups, respectively. There was statistically significantly less ECL after DMEK-only than after triple-DMEK at both 1 month (95% confidence interval [CI]: 1.67-15.02; P = .016) and 1 year (95% CI: 1.06-14.07; P = .034). CCT was significantly lower after DMEK-only than after triple-DMEK at 1 month but not at 1 year. BCVA was excellent and similar in the 2 groups. There were no cases of graft failure. Graft rejection and rebubbling rates were similar in DMEK-only and triple-DMEK groups: rejection occured in 8.8% and 8.75% of cases respectively (P = .50), and rebubbling in 2.9% and 2.5% respectively (P = .44).

CONCLUSIONS

Both the DMEK-only and the triple-DMEK groups had low rebubbling rates and good visual outcomes, but the combined triple-DMEK procedure resulted in significantly greater loss of endothelial cells than DMEK-only surgery at both 1 month and 1 year.

Parameters Associated With Endothelial Cell Density Variability After Descemet Membrane Endothelial Keratoplasty

PURPOSE

To evaluate which parameters may affect endothelial cell loss after Descemet membrane endothelial keratoplasty (DMEK) by comparing eyes in the low vs high quartile of endothelial cell loss over a follow-up period of 4 years.

DESIGN

Retrospective cohort study.

METHODS

Donor endothelial cell density (ECD) decline was evaluated for 351 eyes of 275 patients up to 4 years after DMEK for Fuchs endothelial corneal dystrophy (FECD). Eyes with a postoperative endothelial cell loss in the lower quartile at all available follow-up moments were assigned to Group 1 (n = 51) and those in the upper quartile to Group 2 (n = 42). Multinomial regression was used to assess which covariates were related to greater ECD decline.

RESULTS

Mean endothelial cell loss as compared to preoperative donor ECD for the entire study group was 33 (±16)%, 36 (±17)%, and 52 (±18)% at 1, 6, and 48 months postoperatively. Endothelial cell loss of Group 1 was 12 (±7)%, 13 (±6)%, and 26 (±8)% at, respectively, 1, 6, and 48 months postoperatively, and 59 (±10)%, 64 (±9)%, and 75 (±5)% in Group 2. Partial graft detachment, donor death cause cardiovascular/stroke (vs cancer), postoperative complications other than graft detachment, and severity of preoperative FECD (all P < .01) showed the strongest relation with greater ECD decline.

CONCLUSIONS

DMEK eyes with a completely attached graft and operated in an early stage of FECD may show the lowest endothelial cell loss postoperatively.

FemtoLASIK After Descemet Membrane Endothelial Keratoplasty

PURPOSE

To evaluate the efficacy and safety of femtosecond laser-assisted in situ keratomileusis (FemtoLASIK) to correct the residual refractive error after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

This case series study included 7 eyes that underwent FemtoLASIK after a DMEK surgery. The refractive error, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, corneal topography (Sirius, CSO, Italy), and anterior segment optical coherence tomography (Visante, Carl Zeiss-Meditec AG, Jena, Germany) were registered at each postoperative follow-up visit.

RESULTS

All surgeries were uneventful, with no intraoperative or postoperative complications. The follow-up time after DMEK (before FemtoLASIK surgery) ranged from 18 to 36 months. The post-FemtoLASIK follow-up period ranged from 12 to 60 months. All cases experienced a significant improvement in UDVA after FemtoLASIK, all of them reaching a postoperative UDVA value ≥20/32. None of the eyes lost lines of CDVA, and 1 case showed a gain of lines of CDVA. In all cases, the refractive error, UDVA, and CDVA values remained stable at their respective postoperative follow-up visits. Furthermore, all topographic and pachymetric parameters were stable at the different postoperative follow-up visits.

CONCLUSIONS

Our findings suggest that the residual refractive error after DMEK surgery can be safely and effectively treated with FemtoLASIK.

Avoiding Hyperopic Surprises After Descemet Membrane Endothelial Keratoplasty in Fuchs Dystrophy Eyes by Assessing Corneal Shape

PURPOSE

It is unclear which patients unexpectedly have a hyperopic refractive outcome after combined Descemet membrane endothelial keratoplasty and cataract surgery (triple DMEK). We assessed how corneal shape predicts hyperopia after triple DMEK.

DESIGN

Retrospective cohort study.

METHODS

Patients with Fuchs endothelial corneal dystrophy (FECD) with Scheimpflug examinations before uncomplicated triple DMEK at a tertiary referral center were included. The arithmetic error was calculated (stable postoperative refraction minus predicted refraction). Using multinomial logistic regression, risk ratios of > +0.5 diopter (D) hyperopic and > 0.5 D myopic arithmetic errors were calculated.

RESULTS

In 112 eyes, the median predicted refraction was -0.43 D (interquartile range [IQR], -0.47 to -0.17) with an achieved refraction of -0.63 to 0.56 (IQR). The arithmetic error was 0.34 D (IQR, -0.22 to 0.81). A hyperopic arithmetic error was present in 46% of eyes. FECD eyes with an oblate posterior cornea (Q value >0) had a 3.0 times higher risk of hyperopic shift after triple DMEK (95% confidence interval [CI], 1.3-7.0; P = .011), compared to spherical or prolate corneas (Q value ≤ 0). In eyes with posterior Q > 0, the mean prediction error was +0.50 D higher than in eyes with negative Q values (95% CI, 0.19-0.82; P = .002), independent of corneal thickness.

CONCLUSIONS

Hyperopic surprises after triple DMEK particularly occur in corneas that are flatter centrally than the periphery because of edematous changes (oblate posterior profile). Eyes with a positive Q value on Scheimpflug imaging should be considered for additional power at the intraocular lens level.

Can we predict the refractive outcome after triple Descemet membrane endothelial keratoplasty?

Purpose:

To analyze and correlate corneal parameters with refractive shift after Descemet membrane endothelial keratoplasty combined with cataract surgery (triple Descemet membrane endothelial keratoplasty).

Methods:

This single-center retrospective observational case series included 152 eyes of 152 consecutive patients undergoing triple Descemet membrane endothelial keratoplasty in the first eye for Fuchs endothelial corneal dystrophy. Patients were examined preoperatively, as well as at 3, 6, and 12 months after surgery. The main outcome measures were: refractive shift (predicted refractive outcome based on intraocular lens calculation compared to actual postoperative refractive outcome), central corneal thickness, corneal volume, anterior and posterior corneal curvature, and corneal densitometry. These parameters were analyzed and correlated with the refractive shift after surgery.

Results:

After 3 months from surgery, a mean refractive shift of +1.12 ± 1.10 D was observed and remained stable until the last follow-up at 12 months (+1.24 ± 1.07 D). Correlation analysis showed a weak but significant positive correlation between refractive shift and preoperative posterior curvature (rho = 0.314; p = 0.002) or preoperative posterior densitometry (rho = 0.227; p = 0.008). No correlation was found between refractive shift and preoperative central corneal thickness, corneal volume, anterior curvature, or anterior/mid-cornea densitometry.

Conclusion:

Changes of the posterior cornea may have an influence on the refractive shift. Patients with flatter posterior corneal curvature or higher posterior corneal density seem to exhibit a higher hyperopic shift. The weak correlations indicate a poor predictive value of any preoperative parameter used in our study.

Descemet Membrane Endothelial Keratoplasty: Safety and Outcomes: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature on the safety and outcomes of Descemet membrane endothelial keratoplasty (DMEK) for the surgical treatment of corneal endothelial dysfunction.

METHODS

Literature searches were last conducted in the PubMed and the Cochrane Library databases most recently in May 2017. The searches, which were limited to English-language abstracts, yielded 1085 articles. The panel reviewed the abstracts, and 47 were determined to be relevant to this assessment.

RESULTS

After DMEK surgery, the mean best-corrected visual acuity (BCVA) ranged from 20/21 to 20/31, with follow-up ranging from 5.7 to 68 months. At 6 months, 37.6% to 85% of eyes achieved BCVA of 20/25 or better and 17% to 67% achieved BCVA of 20/20 or better. Mean endothelial cell (EC) loss was 33% (range, 25%-47%) at 6 months. Overall change in spherical equivalent was +0.43 diopters (D; range, -1.17 to +1.2 D), with minimal induced astigmatism of +0.03 D (range, -0.03 to +1.11 D). The most common complication was partial graft detachment requiring air injection (mean, 28.8%; range, 0.2%-76%). Intraocular pressure elevation was the second most common complication (range, 0%-22%) after DMEK, followed by primary graft failure (mean, 1.7%; range, 0%-12.5%), secondary graft failure (mean, 2.2%; range, 0%-6.3%), and immune rejection (mean, 1.9%; range, 0%-5.9%). Overall graft survival rates after DMEK ranged from 92% to 100% at last follow-up. Best-corrected visual acuity after Descemet's stripping endothelial keratoplasty (DSEK) ranged from 20/34 to 20/66 at 9 months. The most common complications after DSEK were graft detachment (mean, 14%; range, 0%-82%), endothelial rejection (mean, 10%; range, 0%-45%), and primary graft failure (mean, 5%; range, 0%-29%). Mean EC loss after DSEK was 37% at 6 months.

CONCLUSIONS

The evidence reviewed supports DMEK as a safe and effective treatment for endothelial failure. With respect to visual recovery time, visual outcomes, and rejection rates, DMEK seems to be superior to DSEK and to induce less refractive error with similar surgical risks and EC loss compared with DSEK. The rate of air injection and repeat keratoplasty were similar in DMEK and DSEK after the learning curve for DMEK.

Descemet membrane endothelial keratoplasty and refractive surgery

PURPOSE OF REVIEW

Descemet membrane endothelial keratoplasty (DMEK) has become a first-line treatment in corneal endothelial diseases because of its exceptional clinical outcomes and low complication rates. Because of its improved refractive predictability, DMEK is now also considered for managing cases with endothelial decompensation following previous refractive procedures, or in combination with those. This article reviews the clinical outcomes in these cases and discusses the possibility of refractive interventions following DMEK.

RECENT FINDINGS

DMEK has been successfully performed in eyes after laser in-situ keratomileusis, eyes after anterior chamber intraocular lens (IOL) implantation and aphakic eyes. Often, DMEK is combined with cataract surgery (triple-DMEK). Initial reports on reducing the refractive cylinder by toric IOL implantation are available. Although there are some reports on phacoemulsification and IOL implantation after phakic DMEK, reports on laser refractive procedures following DMEK are lacking.

SUMMARY

In contrast to earlier keratoplasty techniques, DMEK induces on average only mild refractive shifts owing to the 'natural' restoration of the cornea. As such, DMEK may be ideal in managing corneal decompensation in refractive patients. However, further studies are required to assess the safety and efficacy of DMEK after refractive treatment and of refractive procedures following DMEK.