Precut tissue for Descemet's stripping automated endothelial keratoplasty: vision, astigmatism, and endothelial survival

The expanding roles of eye banks in India: Past, present, and future

This review highlights the evolution in the scope of eye banking activities in India. The roles and responsibilities of the eye banks have expanded to match the requirements and necessities that arose because of advancements in keratoplasty techniques and the need for corneal surgeons. Adoption of different types of corneal preservation solutions and methods of donor cornea preservation was a consequence of the changing and unprecedented times. The growth of eye banking in India has been a commendable journey and has placed the country in an "almost sufficient" category in eye banking and corneal transplantation. There exists a potential to reach the status of cornea surplus country in the future. The rules and laws governing eye banking operations need dynamic amendments based on the trends in keratoplasty, surgical practice patterns, and status of self-sufficiency. Newer technological advances and quality measures must be adopted in donor cornea evaluation and tissue preparation. Research should be integrated as an important component of eye banking, especially in developing novel methods of donor preservation, and evaluating and validating the existing and changing practices of eye banking.

Postoperative, but not preoperative, central corneal thickness correlates with the postoperative visual outcomes of Descemet membrane endothelial keratoplasty

Descemet membrane endothelial keratoplasty (DMEK) restores visual acuity in patients with progressive corneal endothelial diseases such as Fuchs endothelial corneal dystrophy (FECD). However, patients often prefer to delay the surgery as long as possible, even though outcomes are poorer in advanced FECD. A recent study proposed that preoperative central corneal thickness (CCT) of ≥625 μm associated with worse best spectacle-corrected visual acuity (BSCVA) after DMEK for FECD. Since this threshold could signal to both surgeons and patients when to perform DMEK, we further explored the relationship between CCT and BSCVA with a retrospective cohort study. The cohort consisted of all patients with FECD who underwent DMEK in a tertiary-care hospital in 2015-2020 and were followed for 12 months. Extremely decompensated corneas were not included. Relationships between preoperative CCT and BSCVA on days 8 and 15 and months 1, 3, 6, and 12 were examined with Pearson correlation analyses. Eyes with preoperative CCT <625 or ≥625 μm were also compared in terms of postoperative BSCVA. Relationships between postoperative CCT and final BSCVA were also explored. The cohort consisted of 124 first-operated eyes. Preoperative CCT did not correlate with postoperative BSCVA at any timepoint. Eye subgroups did not differ in postoperative BSCVA. However, postoperative CCT at 1-12 months correlated significantly with 12-month BSCVA (r = 0.29-0.49, p = 0.020-0.001). Thus, postoperative, but not preoperative, CCT correlated with postoperative BSCVA. This phenomenon may reflect factors that distort preoperative CCT measurements but disappear after surgery. This observation and our analysis of the literature suggest that while there is a relationship between CCT and post-DMEK visual acuity, preoperative CCT measurements may not always adequately reflect that relationship and may therefore not be a reliable predictor of DMEK visual outcomes.

Graft Thickness at 6 Months Postoperatively Predicts Long-Term Visual Acuity Outcomes of Descemet Stripping Automated Endothelial Keratoplasty for Fuchs Dystrophy and Moderate Phakic Bullous Keratopathy: A Cohort Study

PURPOSE

It remains unclear whether preoperative central graft thickness (CGT) contributes to visual outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK). This retrospective cohort study examined the ability of preoperative and postoperative CGT to predict 12-month best spectacle-corrected visual acuity (BSCVA) after DSAEK for Fuchs endothelial corneal dystrophy/moderate pseudophakic bullous keratopathy/second graft.

METHODS

All consecutive patients who underwent DSAEK in 2015 to 2018 were included. The primary end point was 12-month BSCVA. DSAEK-CGT was measured preoperatively and 6 times between postoperative day 8 and month 12. Eyes were divided according to preoperative CGT 130 μm (ultrathin-DSAEK threshold) or 6-month postoperative CGT 100 μm (mean 6-month postoperative DSAEK-CGT). The t test assessed CGT evolution of the 4 groups over time. Multivariate analyses examined whether preoperative CGT or 6-month CGT categories predicted 12-month BSCVA. Multivariate analysis assessed the preoperative/perioperative factors that predicted 6-month CGT.

RESULTS

A total of 108 eyes (68 patients) underwent DSAEK. Preoperative CGT was >130 and ≤130 μm in 87 and 21 eyes, respectively. Postoperative CGT was >100 and ≤100 μm in 50 and 58 eyes, respectively. Thin 6-month postoperative grafts thinned significantly more relative to preoperative thickness than thick grafts ( P < 0.001). Preoperative CGT subgroups did not show this difference. Six-month postoperative CGT ( P = 0.01), but not preoperative CGT, predicted 12-month BSCVA. Preoperative CGT strongly predicted 6-month CGT ( P = 0.0003).

CONCLUSIONS

Postoperative, but not preoperative, DSAEK-CGT predicted 6-month BSCVA. The correlation between preoperative and postoperative CGT and interstudy variation in preoperative CGT measurement accuracy may explain literature disparities regarding the importance of preoperative CGT in DSAEK outcomes.

Posterior lamellar keratoplasty: techniques, outcomes, and recent advances

Over the past 2 decades, posterior lamellar keratoplasty (PLK) has emerged as an alternative to penetrating keratoplasty in the treatment of corneal endothelial disorders. The reasons for this trend include the search for a safer procedure to replace diseased endothelium that provides faster and better visual rehabilitation and reduces the need for postoperative care. Different surgical techniques, surgical instruments, devices, and lasers have been introduced to overcome technical difficulties, thus improving clinical outcomes. Yet, surgeons and eye banks must address the complications and limitations that arise during the transition to these new techniques. This review discusses the most significant aspects of the evolution of PLK, including a detailed description of current techniques and the direction of future treatment for corneal endothelial disease with the use of laser-assisted surgery, bioengineered corneas, cell therapy, and new pharmacologic therapy.

Tissue Loss, Processing Time, and Primary Graft Failure in Eye Bank-Prepared Descemet Membrane Endothelial Keratoplasty Grafts Before and After Prestripped to Preloaded Graft Transition

PURPOSE

To examine tissue loss rates, processing time, and primary graft failure (PGF) of "prestripped-only" Descemet membrane endothelial keratoplasty (DMEK) grafts at a single eye bank and how these parameters changed after the introduction of steps to preload tissue among experienced processors.

METHODS

Tissue loss and processing time during DMEK graft preparation as well as PGF were analyzed retrospectively at a single eye bank between 2012 and 2018. Outcomes were assessed in consecutive grafts before and after the introduction of preloading to the eye bank's standard operating procedure.

RESULTS

A total of 1326 grafts were analyzed, composed of the first 663 preloaded DMEK grafts and, for comparison, the 663 DMEK grafts processed immediately before starting the preloaded service. Mean processing time increased from 17.0 ± 3.9 minutes to 26.0 ± 5.4 minutes with the advent of preloading (P < 0.01). Initially, average processing time increased dramatically, with a maximum processing time of 51 minutes, before regressing to the average. No significant difference in the rate of tissue wastage was observed before versus after the implementation of preloaded DMEK (1.2% vs. 1.7%, P = 0.48). PGF occurred in 7 grafts before the preloaded service and 10 grafts after starting the service (1.6% vs. 2.3%, P = 0.47).

CONCLUSIONS

Preloading does not affect tissue wastage for experienced technicians or the PGF rate but increases processing time. Eye banks that are considering adding preloading to their standard operating procedure may need to account for longer processing times in their daily operations.

Anterior Chamber Characteristics, Endothelial Parameters, and Corneal Densitometry After Descemet Stripping Automated Endothelial Keratoplasty in Patients With Fuchs Dystrophy

Purpose

To compare anterior segment parameters in patients with Fuchs endothelial dystrophy (FED) who underwent Descemet stripping automated endothelial keratoplasty (DSAEK) in one eye and no corneal surgery in the fellow eye.

Methods

This prospective study was conducted on 28 eyes of 14 patients with FED who underwent DSAEK in one eye at least one year prior (DSAEK group) and no corneal surgery in the fellow eye (control group). Each eye was analyzed with the anterior segment optical coherence tomography, specular microscopy, and Scheimpflug imaging systems. Data were compared between the two groups.

Results

The mean age of the patients was 76.9 ± 7.0 years. There were no statistically significant differences in the mean central corneal thickness (CCT), central anterior chamber depth, anterior chamber angle parameters, cylinder and keratometry values between two groups (all P-values > 0.05). The paracentral corneal thickness, corneal volume, endothelial cell density, and hexagonal cell ratio measurements were statistically significantly higher in the DSAEK group than the control (all P-values < 0.05), and anterior chamber volume in the DSAEK group was significantly less than the control (P = 0.046). While posterior and total corneal densitometry values in the DSAEK group were statistically significantly lower than the control (P < 0.001 and P = 0.011, respectively), there were no statistically significant differences in the anterior or middle corneal densities (P = 0.108 and P = 0.134, respectively).

Conclusion

We found that total corneal densitometry value decreased in DSAEK group. Although DSAEK surgery did not affect the anterior chamber angle parameters, it reduced the anterior chamber volume and increased the corneal volume and paracentral corneal thickness due to the addition of the DSAEK graft.

Descemet Stripping Automated Endothelial Keratoplasty: The influence of preoperative endothelial cell density and triple procedures on grafts at 5 years postoperative

The purpose is to determine if the preoperative central endothelial cell density (ECD) in triple (phacoemulsification plus intraocular lens implantation plus DSAEK) and non-triple Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) procedures have a relationship with the 5-year postoperative ECD or percent Endothelial Cell Loss (ECL).Out of 986 consecutive DSAEK surgeries for Fuchs dystrophy, 241 eyes had 5-year ECD measurements available. Endothelial cell densities were then evaluated against preoperative ECDs to obtain measures of ECL. Triple and non-triple procedures were isolated and compared independently.One hundred eighty two eyes had undergone a triple procedure and 59 had not. The mean ECD at 5 years was 1560 ± 648 cells/mm for triples and 1483 ± 621 cells/mm for non-triples (P = .42). Endothelial Cell loss was 44.4% ± 21.7% and 44.4% ± 22.0%, respectively for eyes that underwent a triple or non-triple (P = .99). There was a moderate, but significant correlation between preoperative ECD and the ECD at 5 years after DSAEK for both triples (r = 0.39, P < .001), and non-triples (r = 0.32, P = .01), respectively.In Descemets stripping automated endothelial keratoplasty grafts, higher preoperative donor ECD was correlated with higher ECD at 5 years postoperatively but was unaffected by a concurrent cataract surgery in the triple procedure.

Corneal transplantation after failed grafts: Options and outcomes

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Because of the large number of transplants, corneal graft failure has become one of the most common indications for corneal transplantation. The relatively recently developed lamellar transplant techniques have brought about specific potential complications leading to graft failure that may require different approaches to repeat transplantation other than penetrating keratoplasty. On the other hand, these new lamellar techniques also provide novel ways of rescuing failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as reduced intraoperative risks and faster visual rehabilitation. We summarize the incidence and risk factors of graft failure for penetrating and lamellar (stromal and endothelial) corneal transplants and discuss the various surgical alternatives currently available to rescue such failed grafts, with a focus on the reported outcomes and limitations.

Late Spontaneous Reabsorption of Interface Fluid after Descemet's Stripping Automated Endothelial Keratoplasty Surgery

An 80-year-old male was referred to our hospital for chronic bullous keratopathy in the right eye. Ten years before, he was affected by an attack of primary acute angle closure glaucoma in high hyperopia and Fuchs' endothelial dystrophy. A bilateral iridotomy was performed. Thereafter, the patient developed an endothelial decompensation in the left eye, and, in another hospital, he underwent an open-sky combined cataract extraction and penetrating keratoplasty. Our surgical approach for the right eye consisted of phacoemulsification and, after 1 month, a Descemet's stripping automated endothelial keratoplasty (DSAEK). After the procedure, an interface fluid was suspected, and an anterior segment optical coherence tomography (OCT) confirmed it. The graft was well centered but thickened, showing no movement in the anterior chamber, adherent to the periphery of the recipient cornea but with a pool of fluid in the center. Seven days postoperatively, an anterior segment OCT showed initial signs of reabsorption of the fluid. On day 45, the graft was adherent with normal thickness and the interface fluid had completely disappeared. The corneal stroma was clear, but a faint interface opacity appeared and is still present. We obtained a good surgical result and best corrected visual acuity was 7/10 at postoperative month 4. No further surgical procedures are scheduled.

[Clinical results of posterior lamellar femto-keratoplasty in patients with corneal endothelial dystrophies]

PURPOSE

To evaluate clinical results of posterior lamellar keratoplasty performed with Russian femtosecond laser «Vizum» for treating patients with primary and secondary corneal endothelial dystrophies.

MATERIAL AND METHODS

The study included 30 operated eyes: 10 with Fuch's primary endothelial dystrophy of the cornea and 20 with secondary endothelial dystrophy. Patients were examined on the 7th day, as well as at 3, 6, 12 and 24 months after the surgery. All 28 patients (30 eyes) were followed-up for 12 months, 12 patients (14 eyes) were followed-up for 24 months.

RESULTS

In 3 months after the surgery, transparent engraftment was observed in most cases. In 1 case, its primary failure was diagnosed and repeated keratoplasty was performed. Postoperative haze in host-donor interface was observed in 1 case. Central corneal thickness (CCT) was 554±43 µm. Transplant thickness in the central zone was 80±13 µm. The amount of eyes with Best Spectacle-Corrected Visual Acuity (BSCVA) of 0.3 was 43%. Endothelial cells density (ECD) was 1538±500 cells/mm². Endothelial cells loss amounted to 30.4%. By the 12th month, recipient's cornea and the transplant remained transparent in all cases. Haze in the host-donor interface was still observed in 1 case. CCT was 581±47 µm, transplant thickness was 80±16 µm. The amount of eyes with BSCVA of 0.3 was 53%. Keratometry astigmatism was 2.08±1.47 D, refractive astigmatism - 1.72±0.83 D. ECD was 1324±383 cells/mm². Endothelial cells loss amounted to 40.1%. At 24th months after the surgery (12 patients, 14 eyes) the recipient's cornea and the transplant remained clear in all cases. CCT was 591±48 µm, transplant thickness was 81±15 µm. Amount of eyes with BSCVA of 0.3 was 71.4%. ECD was 1426±422 cells/mm². Endothelial cells loss - 35.1%.

CONCLUSIONS

The predictability of applanation and high quality of cutting of the «Vizum» femtosecond laser assure the predictability of the process of preparing an ultrathin cornel graft from the endothelial side. Clinical results have demonstrated its effectiveness for rehabilitation of visual functions (up to BSCVA 1.0).

[Refractive changes after different modifications of endothelial keratoplasty]

PURPOSE

To evaluate changes in clinical refraction after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) and Descemet Membrane Endothelial Keratoplasty (DMEK), and assess their correlation to the thickness of the transplant.

MATERIAL AND METHODS

The main study group included 40 patients (40 eyes) after DSAEK and 20 patients (20 eyes) after DMEK, the control group consisted of 20 patients (20 eyes) without any corneal pathologies or history of surgical treatment. In addition to standard examination, patients of the main group had central corneal thickness and transplant thickness regularly measured; they were also monitored by optical coherence tomography (Optovue, U.S.A.), computed tomography and aberrometry of the cornea performed on Pentacam device. The control group had the same examination regimen.

RESULTS

Best corrected visual acuity after 6 months was on average 0.2 higher in DMEK patients compared to those who underwent DSAEK; after one year - 0.1 higher. Clinical refraction data shows presence of hypermetropic changes after DSAEK surgery. Induced astigmatism after one year was 0.4 Diopters in DSAEK patients, but did not exceed 0.1 Diopters in DMEK patients. Stabilization of the corneal thickness in DMEK group occurred on the 3-4^th month, in DSAEK group - 6-7^th month. Certain values of higher-order aberrations (3-6) and root-mean-square deviation (RMS) of the wave-front of anterior corneal surface in DSAEK and DMEK groups were higher than in the control group. Aberrations on the posterior corneal surface in DMEK group were significantly lower than in DSAEK group. There were no statistically significant differences in 'final' RMS higher-order aberrations between DMEK and DSAEK groups.

Changing indications and surgical techniques for keratoplasty during a 16-year period (2003-2018) at a tertiary referral hospital in Japan

Purpose

To present the changing indications and surgical techniques for keratoplasty during a 16-year period (2003–2018) at a tertiary referral hospital in Japan.

Methods

Consecutive keratoplasty cases at Kanazawa University Hospital from January 2003 to December 2018 were retrospectively reviewed. Keratoplasty procedures included penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), anterior lamellar keratoplasty (ALK), Descemet’s stripping automated endothelial keratoplasty (DSAEK), and Descemet’s membrane endothelial keratoplasty (DMEK). Annual numbers and types of keratoplasty as well as underlying diseases for PK and total keratoplasty procedures were recorded, and annual trends were statistically analyzed using Cochran–Armitage test for trend.

Results

A total of 801 keratoplasty procedures (PK, 319 cases; DALK, 57 cases; ALK, 9 cases; DSAEK, 371 cases; and DMEK 45 cases; mean age, 66.9±16.3 years) were performed for 595 patients (302 males [329 eyes, 419 cases], 293 females [345 eyes, 382 cases]) during the 16-year period. The proportion of PK procedures decreased significantly in the beginning and showed a slightly increasing trend after a plateau around 2015. DSAEK was increasing after 2006 and reached a plateau around 2012. Among 10 underlying diseases for total keratoplasty, corneal opacity and dermoid were decreasing linearly. Failed PK and failed DSAEK were increasing linearly in the beginning and reached a plateau followed by a decreasing trend. In terms of the underlying disease for PK, bullous keratopathy was decreasing in the beginning and reached a plateau around 2015. A total of 19 PK procedures were performed on cases with recalcitrant bullous kerstopathy (BK) after 2010.

Conclusion

The distribution of keratoplasty procedures and underlying diseases changed significantly over 16 years at a tertiary referral hospital in Japan. PK procedure was significantly decreased and DSAEK procedure was significantly increased. PK for BK decreased significantly; however, PK remains a viable option for other recalcitrant corneal diseases.

Evaluation of interface reflectivity and corneal aberrations following Descemet's stripping automated endothelial keratoplasty

PURPOSE:

This study aims to evaluate visual outcome after Descemet's membrane stripping automated endothelial keratoplasty (DSAEK) and relate to interface and corneal higher-order aberrations (HOAs).

MATERIALS AND METHODS:

We enrolled 16 eyes of 16 patients (eight males and eight females) in this interventional case series and followed DSAEK operation for about two to 20 months. OCULUS Pentacam, as well as other ophthalmic evaluations in follow-up visits, examined interface reflectivity and HOAs. Statistical relations were analyzed.

RESULTS:

There was statistically significant correlation between interface reflectivity and best corrected visual acuity (BCVA) (r = 0.56, P = 0.021). Pachymetry (central corneal thickness) and BCVA had a moderate correlation (r = 0.6, P = 0.013). There was no statistically significant correlation between pachymetry and follow-up time (r = −0.36, P = 0.16). Negative correlation between follow-up and interface reflectivity was also not statistically significant (r = −0.24, P = 0.35). Coma had a significant correlation with BCVA in cornea and cornea front maps (r = 0.74, P = 0.009 and r = 0.71, P = 0.013, respectively).

CONCLUSION:

Significant correlation between interface reflectivity and BSCVA was found, and anterior corneal HOAs are significantly higher than posterior HOAs.

Effect of Cornea Preservation Time on Success of Descemet Stripping Automated Endothelial Keratoplasty: A Randomized Clinical Trial

Importance

Demonstrating that success of Descemet stripping automated endothelial keratoplasty is similar across donor cornea preservation times (PTs) could increase the donor pool.

Objective

To determine whether the 3-year rate of graft success using corneal donor tissue preserved 8 to 14 days is noninferior to that of donor tissue preserved 7 days or less.

Design, Setting, and Participants

A multicenter, double-masked, randomized noninferiority clinical trial was conducted from April 16, 2012, to June 5, 2017, at 40 clinical sites (70 surgeons) in the United States, with donor corneas provided by 23 US eye banks. A total of 1090 individuals (1330 study eyes) underwent Descemet stripping automated endothelial keratoplasty (1255 eyes [94.4%] for Fuchs endothelial corneal dystrophy).

Interventions

Descemet stripping automated endothelial keratoplasty with random assignment of a donor cornea with a PT of 7 days or less (0-7d PT) or 8 to 14 days (8-14d PT).

Main Outcomes and Measures

Graft success at 3 years.

Results

Of the 1090 participants (1330 study eyes; 60.2% women and 39.8% men; median age at enrollment, 70 years [range, 42-90 years]), the 3-year cumulative probability of graft success was 95.3% (95% CI, 93.6%-96.9%) in the 0-7d PT group and 92.1% (95% CI, 89.9%-94.2%) in the 8-14d PT group (difference, 3.2%). The upper limit of the 1-sided 95% CI on the difference was 5.4%, exceeding the prespecified noninferiority limit of 4%. The difference was mostly owing to more primary donor failures in the 8-14d PT group, with the conditional probability of failure after the first month being 2.4% in the 0-7d PT group and 3.1% in the 8-14d PT group. In preplanned secondary analyses, longer PT was associated with a lower rate of graft success (unadjusted hazard ratio for graft failure per additional day of PT, 1.10; 95% CI, 1.03-1.18; P = .008 [PT analyzed as days]), with success rates of 96.5% (95% CI, 92.3%-98.4%) for PT of 4 days or less, 94.9% (95% CI, 92.5%-96.6%) for PT of 5 to 7 days, 93.8% (95% CI, 91.0%-95.8%) for PT of 8 to 11 days, and 89.3% (95% CI, 84.4%-92.7%) for PT of 12 to 14 days (P = .01 [PT analyzed as categorical variable]).

Conclusions and Relevance

The 3-year success rate in eyes undergoing Descemet stripping automated endothelial keratoplasty was high irrespective of PT. However, the study was unable to conclude that the success rate with donor corneas preserved 8 to 14 days was similar to that of corneas preserved 7 days or less with respect to the prespecified noninferiority limit. Although longer PT was associated with a lower success rate, the difference in rates was small when PT was less than 12 days.

Corneal Endothelial Cell Loss 3 Years After Successful Descemet Stripping Automated Endothelial Keratoplasty in the Cornea Preservation Time Study: A Randomized Clinical Trial

Importance

Demonstrating that endothelial cell loss following Descemet stripping automated endothelial keratoplasty (DSAEK) is independent of donor cornea preservation time (PT) could increase the pool of corneal tissue available for keratoplasty.

Objective

To determine whether endothelial cell loss 3 years after successful DSAEK is related to PT.

Design, Setting, and Participants

A multicenter, double-masked, randomized clinical trial included 40 clinical sites (70 surgeons) in the United States, with donor corneas provided by 23 US eye banks. A total of 945 eyes of 769 participants were included in the Cornea Preservation Time Study that had not experienced graft failure 3 years after DSAEK, performed primarily for Fuchs endothelial corneal dystrophy (96% of the cohort). The study was conducted from April 16, 2012, to June 5, 2017.

Interventions

DSAEK with random assignment of a donor cornea with PT of 0 to 7 days (0-7d PT) or 8 to 14 days (8-14d PT).

Main Outcomes and Measures

Endothelial cell density (ECD) at 3 years determined by a central image analysis reading center from clinical specular or confocal central endothelial images.

Results

Nine hundred forty-five eyes of 769 participants (median age, 70 years [range, 42-90 years], 60.8% women, 93.0% white) in the Cornea Preservation Time Study that had not experienced graft failure 3 years after DSAEK were included. At the initial eye bank tissue screening, mean (SD) central ECD was 2746 (297) cells/mm2 in the 0-7d PT group (n = 485) and 2723 (284) cells/mm2 in the 8-14d PT group (n = 460). At 3 years, the mean (SD) ECD decreased from baseline by 37% (21%) in the 0-7d PT group and 40% (22%) in the 8-14d PT group to 1722 (626) cells/mm2 and 1642 (631) cells/mm2, respectively (mean difference, 73 cells/mm2; 95% CI, 8-138 cells/mm2; P = .03). When analyzed as a continuous variable (days), longer PT was associated with lower ECD (mean difference by days, 15 cells/mm2; 95% CI, 4-26 cells/mm2; P = .006). Endothelial cell loss (ECL) was comparable from 4 to 13 days’ PT (n = 878; 36%-43% when tabulated by day). Available extension study ECD results at 4 years mirrored those at 3 years in the 203 eyes in the 0-7d PT group (mean [SD] ECD, 1620 [673] cells/mm2 and mean [SD] ECL, 41% [23%]) and 209 eyes in the 8-14d PT group (mean [SD] ECD, 1537 [683] cells/mm2 and mean [SD] ECL, 44% [23%]) (mean difference, 112 cells/mm2; 95% CI, 5-219 cells/mm2; P = .04).

Conclusions and Relevance

Although ECL 3 years after Descemet stripping automated endothelial keratoplasty is greater with longer PT, the effect of PT on ECL is comparable from 4 to 13 days’ PT.

Endothelial keratoplasty: The relationship between recipient anterior chamber depth and endothelial cell loss

PURPOSE

To determine the relationship between anterior chamber depth (ACD) and percent endothelial cell loss (ECL) after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK).

METHOD

In 78 eyes receiving triple procedure (DSAEK combined with cataract extraction and posterior chamber intraocular lens (PCIOL) implantation), ACD was measured preoperatively with an intraocular lens (IOL) Master and ECL was calculated with specular microscopy at 6 months, 1, 2, 3, and 4 years postoperatively. ACD and ECL from all 78 eyes were compared using correlation analysis and students t test. Eyes were then separated into 2 groups based on ACD, group 1 with ACD < 3mm and group 2 with ACD ≥ 3mm. Students t test was then performed to compare group 1 and group 2 ECL at 6 months, 1, 2, 3, and 4 years postoperative.

RESULTS

Mean ACD for all 78 eyes was 2.93 ± 0.43 mm. Mean ECL was 32.7%, 27.6%, 29.6%, 32.5%, and 37.2% at 6 months, 1, 2, 3, and 4 years. No significant correlation between ACD and ECL was observed at any time point for the combined analysis of 78 eyes (P > .05). At 2 and 4 years postoperative, mean ECL was 32.6% ± 16.1% and 43.0% ± 23.2% in eyes with ACD < 3mm and 25.3% ± 13.0% and 29.6% ± 18.2% in eyes with ACD ≥ 3 mm (P = .041 at 2 years and .008 at 4 years).

CONCLUSION

ACD and ECL were not directly correlated; however, there may be a threshold ACD in which shallower anterior chambers preoperatively result in greater donor ECL over time.

Effect of Donor Graft Thickness on Clinical Outcomes after Descemet Stripping Automated Endothelial Keratoplasty

Purpose

To evaluate the effects of donor graft thickness on postoperative best spectacle-corrected visual acuity (BSCVA), refractive outcomes, endothelial cell density (ECD) and function, intraocular pressure (IOP), and postoperative complications after Descemet stripping automated endothelial keratoplasty (DSAEK).

Methods

This retrospective, interventional case series enrolled 77 eyes of 64 patients who underwent DSAEK with or without simultaneous cataract surgery. Clinical outcomes, including BSCVA, refraction, keratometric astigmatism, IOP, and ECD were assessed at the final follow-up examination. Univariate analyses were used to investigate the effects of postoperative donor graft thickness on clinical outcomes and complications.

Results

The mean patient age was 62.3 ± 15.6 years, and the patients were followed for 26.2 ± 20.9 months postoperatively. The mean postoperative central graft thickness was 102.4 ± 31.6 μm. In the univariate analysis, postoperative central graft thickness was significantly associated with postoperative IOP (P = 0.005), central recipient thickness (P = 0.002), and ECD (P = 0.016). No significant association was found for central graft thickness with postoperative BSCVA (P = 0.70), spherical equivalent refraction (P = 0.33), keratometric astigmatism (P = 0.27), graft detachment (P = 0.16), graft decentration (P = 0.17), high IOP (P = 0.53), or endothelial rejection (P = 0.88).

Conclusion

This study failed to demonstrate any significant correlation between graft thickness and BSCVA. Attempting to minimize graft thickness might not have the desired outcome regarding endothelial cell density and function. Increased graft thickness could negatively impact the accuracy of IOP measurements after DSAEK.

A 10-year review of underlying diseases for endothelial keratoplasty (DSAEK/DMEK) in a tertiary referral hospital in Japan

Purpose

To report a 10-year review of endothelial keratoplasty (EK) procedures, Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), and underlying diseases at a tertiary referral hospital in Japan.

Study design

A single-center, retrospective case series.

Methods

We retrospectively reviewed all medical records of bullous keratopathy (BK) surgically treated by EK (DSAEK/DMEK) at Kanazawa University Hospital from January 2007 to December 2016. Changes or modifications to the annual number of EK procedures and underlying diseases were analyzed.

Results

During this period, 320 EK procedures (DSAEK: 288 cases, DMEK: 32 cases) were performed on 250 patients. Total annual EKs gradually increased from 19 to 45 cases between 2007 and 2016. The annual number of DSAEKs was stable, although the proportion of DSAEKs to other procedures decreased significantly as re-DSAEKs and DMEKs increased. BK after argon laser iridotomy (ALI) was the leading cause in 2007, followed by Fuchs' endothelial dystrophy (FED) and failed penetrating keratoplasty. In 2016, BK after trabeculectomy (TLE) was most prevalent, followed by failed DSAEK, failed penetrating keratoplasty, and pseudophakic BK. The decreased ALI and FED, and increased BK after TLE and failed DSAEK were statistically significant.

Conclusion

The distribution of EK procedures (DSAEK/DMEK) and underlying diseases changed over 10 years at a tertiary referral hospital in Japan. The proportion of re-DSAEK and DMEK increased among all EK procedures. Most significantly, among the underlying diseases, decreased ALI and FED and increased TLE and failed DSAEK were observed. Extended multicenter analysis may further elucidate the changes in EK procedures and the causes of BK in Japan.

Factors Limiting the Visual Outcome After Descemet Stripping Automated Endothelial Keratoplasty: Comprehensive Analysis Including the Graft Position and Irregularity

PURPOSE

To investigate factors affecting best postoperative corrected distance visual acuity (CDVA) in patients who have undergone Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

Forty-two eyes of 42 patients with predominantly non-Fuchs endothelial corneal dystrophy after DSAEK were retrospectively evaluated. All patients were examined using anterior segment optical coherence tomography when their best postoperative CDVA had been achieved. We analyzed the relationship between best postoperative CDVA and preoperative, intraoperative, and postoperative factors, including corneal higher-order aberrations (HOAs), corneal backward scattering, graft irregularity, and graft decentration. Variables with P < 0.2 in univariate analysis were entered into a multivariate linear regression model to determine the factors affecting best postoperative CDVA.

RESULTS

Mean CDVA improved from 1.16 ± 0.46 preoperatively to 0.22 ± 0.19 logarithm of the minimum angle of resolution equivalents postoperatively (P < 0.0001). Best postoperative CDVA was achieved 11.6 ± 7.7 months after DSAEK. Multivariate analysis showed that anterior corneal coma-like HOAs and venting incisions inside the pupil area were significantly correlated with best postoperative CDVA (t = 2.90, P = 0.006; t = 2.62, P = 0.01, respectively). No significant relationship was found between the visual outcome and any other factor, including posterior corneal HOAs, corneal backward scattering, graft decentration, and graft irregularity.

CONCLUSIONS

Irregularity of the anterior corneal surface and venting incisions inside the pupil area are important factors that impair best postoperative CDVA in patients who have undergone DSAEK. In contrast, our results indicate that the graft position and irregularity might not have a strong influence on the visual outcome after DSAEK.

Effect of venting incisions on graft attachment in Descemet's stripping automated endothelial keratoplasty

Purpose

To investigate the impact of venting incisions on the adherence of graft to the recipient's stroma in Descemet's stripping automated endothelial keratoplasty (DSAEK).

Methods

Fifty-six patients were enrolled in this study. Patients were randomly allocated into two groups. Twenty-eight patients had a DSAEK procedure with venting incisions. The second group was treated by conventional DSAEK with no venting incisions. Slit-lamp examination and anterior segment optical coherence tomography (AS-OCT) were performed in day one and 14 days after surgery to investigate graft attachment. The thickness of cornea and lenticle were also evaluated by AS-OCT. BCVA (logMAR) was measured the day before the surgery and 14 days postoperatively.

Results

Subclinical graft detachment in the first day after surgery was significantly lower in patients who had a DSAEK procedure and venting incisions (P = 0.02), but no difference was noted in the rate of clinical graft detachment on day one (P = 0.24) and subclinical and clinical graft detachment on day 14 (P = 0.24, P = 0.50, respectively). The thickness of the cornea and lenticle after the surgery were statistically similar between the two groups (P = 0.903, P = 0.402, respectively). No difference in the improvement of BCVA was observed between the venting and non-venting group (P = 0.143).

Conclusions

Routine use of venting incisions may not be necessary in the standard DSAEK procedures. More studies with larger sample sizes are needed to better confirm the results of this study.

Corneal Endothelial Cell Integrity in Precut Human Donor Corneas Enhanced by Autocrine Vasoactive Intestinal Peptide

PURPOSE

To demonstrate that vasoactive intestinal peptide (VIP), a corneal endothelial (CE) cell autocrine factor, maintains the integrity of corneal endothelium in human donor corneoscleral explants precut for endothelial keratoplasty.

METHODS

Twelve paired human donor corneoscleral explants used as control versus VIP-treated explants (10 nM, 30 minutes, 37°C) were shipped (4°C) to the Lions Eye Institute for Transplantation and Research for precutting (Moria CBM-ALTK Keratome), shipped back to the laboratory, and cultured in ciliary neurotrophic factor (CNTF, 0.83 nM, 37°C, 24 hours). Trephined endothelial discs (8-8.5 mm) were analyzed for differentiation markers (N-cadherin, CNTF receptor α subunit [CNTFRα], and connexin 43) by Western blot after a quarter of the discs from 4 paired explants were cut away and stained with alizarin red S for microscopic damage analysis. Two additional paired explants (6 days in culture) were stained for panoramic view of central CE damage.

RESULTS

VIP treatment increased N-cadherin and CNTFRα levels (mean ± SEM) to 1.38 ± 0.11-fold (P = 0.003) and 1.46 ± 0.22-fold (P = 0.03) of paired controls, respectively, whereas CE cell CNTF responsiveness in upregulation of connexin 43 increased to 2.02 ± 0.5 (mean ± SEM)-fold of the controls (P = 0.04). CE damage decreased from (mean ± SEM) 10.0% ± 1.2% to 1.6% ± 0.3% (P < 0.0001) and 9.1% ± 1.1% to 2.4% ± 1.0% (P = 0.0006). After 6 days in culture, the damage in whole CE discs decreased from 20.0% (control) to 5.5% (VIP treated).

CONCLUSIONS

VIP treatment before precut enhanced the preservation of corneal endothelium.

Descemet stripping automated endothelial keratoplasty

Endothelial keratoplasty is at present the gold standard for surgical treatment of corneal endothelial pathologies not associated with significant corneal scar. Tremendous progress has been made in recent years in improving the technology of endothelial keratoplasty techniques, such as descemet stripping automated endothelial keratoplasty (DSAEK) and descemet membrane endothelial keratoplasty. In this review, we discuss the current techniques and outcomes of DSAEK.

Incidence of cystoid macular edema after Descemet's stripping automated endothelial keratoplasty

AIM

To determine the incidence of cystoid macular edema (CME) after Descemet's stripping automated endothelial keratoplasty (DSAEK).

METHODS

This study included all consecutive patients operated in a Spanish tertiary reference hospital over a period of four years. A total of 55 eyes from 47 patients matched the selection criteria. CME was diagnosed clinically at the slit-lamp and confirmed by optical coherence tomography.

RESULTS

Six cases of CME were diagnosed postoperatively, which represented an incidence of 11%. Three patients had previously undergone DSAEK alone (7%; 3/41) and the other three, DSAEK combined with phacoemulsification (21%; 3/14). Five out of six patients with CME responded to standard therapy.

CONCLUSION

CME is a possible complication after DSAEK and can be treated with standard therapy. CME appears more frequently when DSAEK is combined with phacoemulsification and posterior chamber (PC) intraocular lens (IOL) implantation. Intraoperative damage to the corneal endothelial cells might play a role in the pathogenesis of CME. As long as the causes remain unclear, we recommend administering prophylaxis when risk factors are present or when combined surgery is planned.

Evaluation of Visual Quality in Patients With Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is a bilateral corneal endothelial dystrophy characterized by the deposition of extracellular matrix (guttae), thickening of Descemet membrane, and progressive loss of corneal endothelial cells. Progressive endothelial cellular loss leads to corneal edema and impairs visual function. In eyes with FECD, corneal edema begins in the central cornea and expands into the periphery. FECD is the most common dystrophic reason for corneal transplantation in many countries. Some patients with FECD report visual discomfort despite the absence of corneal edema. Intraocular forward light scatter impairs patients' quality of vision (QOV), and corneal guttae associated with FECD may cause intraocular light scatter and glare, which can be extremely debilitating despite the absence of edema. We recently investigated the effect of the severity of corneal guttae on QOV in patients with mild FECD. It was shown that corneal guttae increased forward light scatter that negatively affected QOV in eyes with mild FECD without severe corneal edema. Therefore, quantification of corneal guttae would be useful to determine surgical indications for eyes with mild FECD. This review discusses QOV in patients with FECD.

Outcomes of descemet stripping automated endothelial keratoplasty using imported donor corneas

Background

The lack of development of local donor tissue acquisition in several regions of the world has resulted in the necessity of performing keratoplasty with imported donor corneas. The greatest concern about the use of donor corneas supplied by foreign eye banks is the effect of the increased donor death-to-operation time which inevitably occurs during the tissue recovery, tissue processing, and tissue transfer between the countries. The purpose of this study was to report the outcomes of descemet stripping automated endothelial keratoplasty (DSAEK) using imported donor corneas.

Methods

This retrospective, non-comparative case series investigated the outcomes of the 102 consecutive DSAEK procedures using imported donor corneas performed at a single university-based hospital between August 2006–2014. The main outcome measures were postoperative best-corrected visual acuity (BCVA), endothelial cell density (ECD), and complications.

Results

The mean death-to-operation time was 9.52 ± 1.48 days (range, 8–13). The mean preoperative ECD was 2761 ± 285 cells/mm². Fuchs’ endothelial dystrophy was the predominant indication for grafting. The mean follow-up duration was 65.3 months. Ninety-three eyes had improved vision postoperatively (91.18%). BCVA unchanged in 3 eyes due to preexisting macular scar and advanced glaucoma. Primary graft failure occurred in 6 eyes (5.88%). Of the 93 eyes with improved BCVA, 100% had their best corrected vision within the first 1 year. The mean ECD at 6, 12, 24, 36, and 60 months after surgery was 1762 ± 294 cells/mm², 1681 ± 284 cells/mm², 1579 ± 209 cells/mm², 1389 ± 273 cells/mm², and 1251 ± 264 cells/mm² respectively. The mean ECD loss at 6 months, 1 year, 2 years, 3 years, and 5 years after surgery was 36.2%, 39.1%, 42.8%, 49.7%, and 54.7% respectively. The most common complication was graft detachment/dislocation (10.78%). There were no cases of any postoperative infection.

Conclusions

DSAEK with imported donor corneas provides rapid and good visual rehabilitation. The percentages of endothelial cell loss were comparable to those achieved in Western series using domestic corneas in which fresher tissues were available for transplantation.

Comparison of Long-term Clinical Outcomes between Descemet's Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty in Patients with Bullous Keratopathy

Purpose

To compare 2-year clinical outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) in patients with bullous keratopathy.

Methods

A retrospective chart review was performed to obtain 2 years of follow-up data of DSAEK or PK at a single center from March 2009 to September 2012. The study comprised 15 eyes of DSAEK and 11 eyes of PK. Outcome measures included best-corrected visual acuity (BCVA), spherical and keratometric changes, central corneal thickness, endothelial cell density, intraocular pressure, and postoperative complications. Graft survival rate was assessed by Kaplan-Meier survival analysis.

Results

There were no differences in patient baseline characteristics between the two groups. At postoperative 2 years, better BCVA of 0.69 ± 0.51 logarithm of the minimum angle of resolution (logMAR) was found after DSAEK compared to 0.88 ± 0.48 logMAR after PK. Refractive cylinder in DSAEK and PK was −2.60 ± 1.53 and −6.00 ± 1.05 diopters (D), respectively, and keratometric cylinder was 3.27 ± 3.70 and 6.34 ± 3.51 D, respectively, at postoperative 2 years. The difference of mean spherical equivalents between postoperative 1 month and 2 years was 0.84 D after DSAEK and 2.05 D after PK. A hyperopic shift of 1.17 D was present after 2 years of DSAEK. The mean endothelial cell density at postoperative 2 years was 1,548 ± 456 cells/mm² for DSAEK and 1,052 ± 567 cells/mm² for PK, with a cell loss of 19.96% vs. 52.38%, respectively when compared to postoperative 1 month. No significant difference in central corneal thickness was found between DSAEK and PK (592 ± 75 vs. 563 ± 90 µm, respectively). Finally, the 2-year survival rate did not differ significantly between DSAEK and PK (93.3% vs. 81.8%, respectively, p = 0.344).

Conclusions

Compared to PK, DSAEK provided more stable refractive errors with better visual outcome, lower endothelial cell loss, and a lower rate of graft rejection at postoperative 2 years in patients with bullous keratopathy.

The Enigmatic Cornea and Intraocular Lens Calculations: The LXXIII Edward Jackson Memorial Lecture

PURPOSE

To review the progress and challenges in obtaining accurate corneal power measurements for intraocular lens (IOL) calculations.

DESIGN

Personal perspective, review of literature, case presentations, and personal data.

METHODS

Through literature review findings, case presentations, and data from the author's center, the types of corneal measurement errors that can occur in IOL calculation are categorized and described, along with discussion of future options to improve accuracy.

RESULTS

Advances in IOL calculation technology and formulas have greatly increased the accuracy of IOL calculations. Recent reports suggest that over 90% of normal eyes implanted with IOLs may achieve accuracy to within 0.5 diopter (D) of the refractive target. Though errors in estimation of corneal power can cause IOL calculation errors in eyes with normal corneas, greater difficulties in measuring corneal power are encountered in eyes with diseased, scarred, and postsurgical corneas. For these corneas, problematic issues are quantifying anterior corneal power and measuring posterior corneal power and astigmatism. Results in these eyes are improving, but 2 examples illustrate current limitations: (1) spherical accuracy within 0.5 D is achieved in only 70% of eyes with post-refractive surgery corneas, and (2) astigmatism accuracy within 0.5 D is achieved in only 80% of eyes implanted with toric IOLs.

CONCLUSION

Corneal power measurements are a major source of error in IOL calculations. New corneal imaging technology and IOL calculation formulas have improved outcomes and hold the promise of ongoing progress.

Visualization of precut DSAEK and pre-stripped DMEK donor corneas by intraoperative optical coherence tomography using the RESCAN 700

BACKGROUND

To report the feasibility of intraoperative spectral domain optical coherence tomography (OCT) using the RESCAN 700 for the visualization and evaluation of precut Descemet's stripping automated endothelial keratoplasty (DSAEK) and prestripped Descemet's membrane endothelial keratoplasty (DMEK) donor tissue.

METHODS

Precut DSAEK (n = 11), prestripped DMEK (n = 4) preserved in a viewing chamber were examined by intraoperative OCT. Wholly intact donor corneas for penetrating keratoplasty (PK) (n = 8) were also examined as controls. The obtained images were analyzed qualitatively for characteristics of each type of donor.

RESULTS

For each type of donor, characteristic images were consistently obtained by intraoperative OCT in both the front and back views through the viewing chamber. In wholly intact donors for PK, appearance of normal corneal curvature and stromal texture with high reflectivity of epithelium and endothelium cell layers were clearly visualized. In precut DSAEK donors, precut lines were characteristically visualized in addition to the intact donor cornea images. In prestripped DMEK donors, identical OCT images to the intact donor cornea were noted when observed from the anterior surface. However, peripheral partial detachments of Descemet's membrane were characteristically observed in all prestripped DMEK donors when viewed from the back of the viewing chamber.

CONCLUSION

Rapid visualization and rough evaluation of donor tissues for PK, precut DSAEK and prestripped DMEK donor corneas by intraoperative OCT was consistently possible through the viewing chamber. Therefore, this device may be used as an alternative of AS-OCT when the eyebank does not have their own AS-OCT. Although the peripheral detachment in DMEK donors are quite common and clinically non-problematic in DMEK donor quality and subsequent DMEK surgeries, it may be useful to distinguish between wholly intact PK donors and prestripped DMEK donors, enabling to prevent mix-ups of donors, especially when several different types of keratoplasties are scheduled in a same day in one operating theater.

Validation of an endothelial roll preparation for Descemet Membrane Endothelial Keratoplasty by a cornea bank using "no touch" dissection technique

Descemet Membrane Endothelial Keratoplasty (DMEK) selectively replaces the damaged posterior part of the cornea. However, the DMEK technique relies on a manually-performed dissection that is time-consuming, requires training and presents a potential risk of endothelial graft damages leading to surgery postponement when performed by surgeons in the operative room. To validate precut corneal tissue preparation for DMEK provided by a cornea bank in order to supply a quality and security precut endothelial tissue. The protocol was a technology transfer from the Netherlands Institute for Innovative Ocular Surgery (NIIOS) to Lyon Cornea Bank, after formation in NIIOS to the DMEK "no touch" dissection technique. The technique has been validated in selected conditions (materials, microscope) and after a learning curve, cornea bank technicians prepared endothelial tissue for DMEK. Endothelial cells densities (ECD) were evaluated before and after preparation, after storage and transport to the surgery room. Microbiological and histological controls have been done. Twenty corneas were manually dissected; 18 without tears. Nineteen endothelial grafts formed a double roll. The ECD loss after cutting was 3.3 % (n = 19). After transportation 7 days later, we found an ECD loss of 25 % (n = 12). Three days after cutting and transportation, we found 2.1 % of ECD loss (n = 7). Histology found an endothelial cells monolayer lying on Descemet membrane. The mean thickness was 12 ± 2.2 µm (n = 4). No microbial contamination was found (n = 19). Endothelial roll stability has been validated at 3 days in our cornea bank. Cornea bank technicians trained can deliver to surgeons an ECD controlled, safety and ready to use endothelial tissue, for DMEK by "no touch" technique, allowing time saving, quality and security for surgeons.

Effect of Graft Thickness on Visual Acuity After Descemet Stripping Endothelial Keratoplasty: A Systematic Review and Meta-Analysis

PURPOSE

To assess the relationship between graft thickness and best-corrected visual acuity (BCVA) after Descemet stripping endothelial keratoplasty (DSEK).

DESIGN

Systematic review and meta-analysis.

METHODS

PubMed, EMBASE, Web of Science, and conference abstracts were searched for studies published up to October 2015 with standard systematic review methodology. Eligibility criteria included studies evaluating graft thickness in primary DSEK and visual outcomes. There were no restrictions to study design, study population, or language. Correlation coefficients were pooled using random-effects models.

RESULTS

Of 480 articles and conference abstracts, 31 met inclusion criteria (2214 eyes) after full-text review. Twenty-three studies assessed correlations between BCVA and graft thickness, and 8 studies used different statistical methods. All associations were reported dimensionless. Studies generally had small sample sizes and were heterogeneous, especially with respect to data and analysis quality (P = .02). Most studies did not measure BCVA in a standardized manner. The pooled correlation coefficient for graft thickness vs BCVA was 0.20 (95% CI, 0.14-0.26) for 17 studies without data concerns; this did not include 7 studies (815 eyes) that used different statistical methods and did not find significant associations.

CONCLUSIONS

There is insufficient evidence that graft thickness is clinically important with respect to BCVA after DSEK, with meta-analysis suggesting a weak relationship. Although well-designed longitudinal studies with standardized measurements of visual acuity and graft thickness are necessary to better characterize this relationship, current evidence suggests that graft thickness is not important for surgical planning.

Determinants of visual quality after endothelial keratoplasty

Endothelial keratoplasty is now favored over full-thickness penetrating keratoplasty for corneal decompensation secondary to endothelial dysfunction. Although endothelial keratoplasty has evolved as surgeons strive to improve outcomes, fewer patients than expected achieve best corrected visual acuity of 20/20 despite healthy grafts and no ocular comorbidities. Reasons for this remain unclear, with theories including anterior stromal changes, differences in graft thickness and regularity, induced high-order aberrations, and the nature of the graft-host interface. Newer iterations of endothelial keratoplasty such as thin manual Descemet stripping endothelial keratoplasty, ultrathin automated Descemet stripping endothelial keratoplasty, and Descemet membrane endothelial keratoplasty have achieved rates of 20/20 acuity of approximately 50%, comparable to modern cataract surgery, and it may be that a ceiling exists, particularly in the older age group of patients. Establishing the relative contribution of the factors that determine visual quality following endothelial keratoplasty will help drive further innovation, optimizing visual and patient-reported outcomes while improving surgical efficacy and safety.

The First 100 Eyes of Standardized Descemet Stripping Automated Endothelial Keratoplasty versus Standardized Descemet Membrane Endothelial Keratoplasty

PURPOSE

To compare results of the first 100 eyes of Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) that were performed with a standardized technique at a single institution.

DESIGN

Single-center, retrospective case series.

PARTICIPANTS

The first 100 eyes of standardized DSAEK and DMEK that underwent surgery for Fuchs corneal dystrophy at our center. We excluded patients with prior ocular surgery other than cataract surgery to limit confounding variables.

METHODS

Best spectacle-corrected visual acuity (BSCVA; in logarithm of the minimal angle of resolution [logMAR] units) was obtained and specular microscopy of donor corneal tissue was performed before surgery. Postoperative complications, BSCVA, and the percent of endothelial cell loss (ECL) recorded at 6 months were compared with the Student t test. Patients with pre-existing ocular comorbidity that impacted visual potential such as macular degeneration, amblyopia, advanced glaucoma, and other optic neuropathies were excluded from the analysis of visual acuity, but were included for the outcomes of complications and ECL.

MAIN OUTCOME MEASURES

Visual acuity improvement, ECL 6 months after surgery, postoperative complications, iatrogenic primary graft failure (IPGF), and rebubbling.

RESULTS

Of the 200 eyes, 62 DSAEK eyes and 70 DMEK eyes had 6-month BSCVA available and no vision-limiting comorbidities. Mean BSCVA increased from 0.41±0.19 logMAR and 0.27±0.11 logMAR before surgery to 0.20±0.13 logMAR and 0.11±0.13 logMAR 6 months after DSAEK and DMEK, respectively (P<0.001). Seventy-one DSAEK eyes and 70 DMEK eyes had 6-month ECL data available: ECL was 25.9±14.0% after DSAEK and 27.9±16.0% after DMEK (P=0.38). There were no IPGFs in the DSAEK cohort and there were 4 of 100 IPGFs after DMEK (P=0.12). Rebubbling was performed in 2 of 100 eyes after DSAEK and in 6 of 100 eyes after DMEK (P=0.28).

CONCLUSIONS

Compared with DSAEK, DMEK provided better visual recovery and comparable 6-month ECL. The DMEK group had a higher, although not statistically significant, percentage of rebubbling procedures and IPGFs.

Descemet stripping automated endothelial keratoplasty in Fuchs' corneal endothelial dystrophy: anterior segment optical coherence tomography and in vivo confocal microscopy analysis

Background

To evaluate the in vivo corneal changes using in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) in patients with Fuchs’ dystrophy who underwent Descemet stripping automated endothelial keratoplasty (DSAEK) and the relationship between these changes and the postoperative visual recovery up to 1-year follow-up.

Methods

Before DSAEK and 1 day, 3, 6 and 12 months after surgery 31 patients (39 pseudophakic eyes) underwent a complete ophthalmological evaluation including best corrected visual acuity (BCVA), IVCM (subepithelial haze, interface haze, graft thickness) and AS-OCT (graft thickness).

Results

Graft thickness measurements by AS-OCT were strongly correlated to those obtained using IVCM at every follow-up stage (intraclass correlation coefficient = 0.95 to 0.97 between 3 and 12 months, P < 0.001 for all coefficients). No correlation between BCVA and graft thickness measured by AS-OCT at any follow-up stage was found, while at 3 and 6 postoperative months the correlations between BCVA and preoperative subepithelial haze (r = 0.61, P < 0.001 and r = 0.46, P = 0.002), interface haze (r = 0.51, P < 0.001 and r = 0.46, P = 0.003), postoperative subepithelial haze (r = 0.43, P = 0.004 and r = 0.39, P = 0.001) were significant.

Conclusions

The study confirmed corneal subepithelial haze and interface haze as important factors limiting visual acuity after DSAEK, while graft thickness was not related to BCVA.