Factors Influencing Graft Endothelial Cell Density after Descemet Stripping Automated Endothelial Keratoplasty

Influence of time to procurement, incubation and release of organ cultured donor corneas on graft failure after Descemet Stripping Automated Endothelial Keratoplasty

PURPOSE

The aim of the present study was to investigate whether the time from death to procurement, to preservation or the storage time of donor corneas preserved in organ culture influenced the clinical outcome of patients undergoing Descemet stripping automated endothelial keratoplasty (DSAEK) for Fuchs endothelial keratoplasty.

METHODS

We conducted a registry-based study on 776 patients undergoing DSAEK. Data on time from donor death to cornea retrieval (DRT), time from death to preservation (DPT), the preservation time and donor cornea characteristics: age, sex and endothelial cell density (ECD) at the time of release for surgery, were extracted from The Danish Cornea Bank Registry. Data on recipient follow-up were collected from a corneal graft registry. The primary outcome was presence of graft failure within a period from 2 months to 2 years after surgery. Secondary outcomes were DRT, DPT, ECD ≤2300 and gender mismatch between donor and recipient.

RESULTS

Graft failure occurred in 26 patients. The mean preservation time for failed grafts was 34.1 ± 10.0 days (mean ± SD) and 27.3 ± 10.6 days (mean ± SD) for the clear, functional grafts at the 2-year follow-up. A preservation time of >29 days compared with ≤29 days was associated with a lower survival (HR 2.33, 95% CI on 1.06-5.14, p = 0.036) and an increased risk of graft failure (RR 1.53, 95% CI on 1.11-2.10, p = 0.009). For the secondary outcome variables, no difference in the risk of graft failure was observed and did not appear to impact the survival rate of DSAEK patients.

CONCLUSION

Preservation time of donor cornea was associated with graft survival and a prolonged preservation time of more than 4 weeks seemed to lower the 2-year survival.

Severe Corneal Edema Increases ECL From Grafts After DSAEK-Corneal Edema and ECL After DSAEK

OBJECTIVES

To determine the relationship between the preoperative degree of corneal edema in the recipient and the endothelial cell density in grafts after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

This retrospective case series enrolled 111 eyes of 107 patients who underwent DSAEK. The preoperative and postoperative central corneal thickness (CCT) was measured by anterior-segment optical coherence tomography. Eyes were divided into three groups according to the preoperative recipient CCT: group A (mild edema): 550 μm

RESULTS

The recipient CCT (all groups combined) was 805.99±132.70 μm preoperatively and decreased to 656.31±105.02 μm at 1 month, decreased to 626.08±81.40 μm at 6 months, and remained stable between 12 (P=0.144) and 24 months (P=0.485) postoperatively. The mean ECL was 27.34±15.43%, 33.56±17.13%, 39.18±16.71%, and 45.87±14.27% at 1, 6, 12, and 24 months, respectively. The percentage of ECL in group C was higher than that in the other 2 groups through the 24-month follow-up. The difference in ECL between groups A and C was significant at 24 months (group A: 42.45±14.47%; group C: 52.49±10.65%; P=0.019).

CONCLUSIONS

The degree of corneal edema in the recipient was associated with implant ECL. Compared with mild and moderate corneal edema, the severe corneal edema may cause greater ECL after DSAEK.

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Key Words

• dsaek
• endothelial cell loss
• degree of corneal edema

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MESH Headings

• Corneal Diseases/etiology
• Corneal Diseases/surgery
• Corneal Edema/etiology
• Corneal Edema/surgery
• Descemet Stripping Endothelial Keratoplasty/adverse effects
• Descemet Stripping Endothelial Keratoplasty/methods
• Endothelial Cells
• Endothelium, Corneal/transplantation
• Humans
• Retrospective Studies

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Affiliation(s)

Shaofeng Gu Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Rongmei Peng Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Gege Xiao Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Jing Hong Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.

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Efficacy of Thin and Ultrathin Descemet Stripping Automated Endothelial Keratoplasty and Influence of Graft Thickness on Postoperative Outcomes: Systematic Review and Meta-analysis

PURPOSE

To conduct a systematic review and meta-analysis on the efficacy of thin and ultrathin Descemet stripping automated endothelial keratoplasty (T-DSAEK and UT-DSAEK, with graft thickness <130 and <100 µm, respectively), depending on graft thickness.

DESIGN

Systematic review and meta-analysis.

METHOD

PubMed, Cochrane Library, Embase, ClinicalTrials.gov, and ScienceDirect databases were searched until October 1, 2021. We computed random-effect meta-analysis on postoperative outcomes of T/UT-DSAEK, stratified by graft thickness (<80 μm, 80-100 μm, and 100-130 μm). The main postoperative outcome was visual acuity (logarithm of the minimum angle of resolution [logMAR]). Secondary outcomes were pachymetry (μm), endothelial cell count (cell/mm²), spherical equivalent (diopter [D]), rebubbling rate (%), and rejection rate (%). Meta-regressions compared postoperative outcomes depending on graft thickness and search for putative confusion factors.

RESULTS

We included 47 articles for a total of 2141 eyes of 2040 patients. T/UT-DSAEK globally improved visual acuity (effect size = -0.38 logMAR [95% confidence interval {CI} -0.46 to -0.30 logMAR]), without difference depending on graft thickness. Overall, pachymetry improved (-60.6 µm [95% CI -101 to -19.7 µm]), endothelial cell count decreased (-1039 cells/mm² [95% CI -1209 to -868 cells/mm²), spherical equivalent resulted in a hyperopic shift (0.74 D [95% CI -0.50 to 1.97 D), the graft rejection rate was 0.2% (95% CI -0.1% to 0.4%), and the rebubbling rate was 8.7% (95% CI 6.8%-10.5%). Grafts >100 μm induced a hyperopic shift. Metaregressions did not demonstrate differences between the 3 groups (<80 μm, 80-100 μm, or 100-130 μm) in any outcomes.

CONCLUSION

All T/UT-DSAEK thickness groups provided similar visual acuity, pachymetry, endothelial cell count, rejection rate, and rebubbling rate regardless of graft thickness. A hyperopic shift was induced by grafts >100 μm.

Experimental design of a culture approach for corneal endothelial cells of New Zealand white rabbit

The harvesting of corneal endothelial cells (CEC) has received special attention due to its potential as a therapy for corneal blindness. The main challenges are related to the culture media formulation, cellular density at the primary isolation, and the number of passages in which CEC can retain their functional characteristics. To alternate different media formulations to harvest CEC has an impact on the cellular yield and morphology. Therefore, we analyzed four different sequences of growth factor-supplemented Stimulatory (S) and non-supplemented Quiescent (Q) media, upon passages to find the optimal S-Q culture sequence. We assessed cell yield, morphology, procollagen I production, Na⁺/K⁺-ATPase function, and the expression of ZO-1 and Na⁺/K⁺-ATPase. Our results show SQSQ and SQQQ sequences with a balance between an improved cell yield and hexagonal morphology rate. CEC cultured in the SQQQ sequence produced procollagen I, showed Na⁺/K⁺-ATPase function, and expression of ZO-1 and Na⁺/K⁺-ATPase. Our study sets a culture approach to guarantee CEC expansion, as well as functionality for their potential use in tissue engineering and in vivo analyses. Thus, the alternation of S and Q media improves CEC culture. SQQQ sequence demonstrated CEC proliferation and lower the cost implied in SQSQ sequences. We discarded the use of pituitary extract and ROCK inhibitors as essential for CEC proliferation.

Deep Learning for Assessing the Corneal Endothelium from Specular Microscopy Images up to 1 Year after Ultrathin-DSAEK Surgery

Purpose

To present a fully automatic method to estimate the corneal endothelium parameters from specular microscopy images and to use it to study a one-year follow-up after ultrathin Descemet stripping automated endothelial keratoplasty.

Methods

We analyzed 383 post ultrathin Descemet stripping automated endothelial keratoplasty images from 41 eyes acquired with a Topcon SP-1P specular microscope at 1, 3, 6, and 12 months after surgery. The estimated parameters were endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX). Manual segmentation was performed in all images.

Results

Our method provided an estimate for ECD, CV, and HEX in 98.4% of the images, whereas Topcon's software had a success rate of 71.5% for ECD/CV and 30.5% for HEX. For the images with estimates, the percentage error in our method was 2.5% for ECD, 5.7% for CV, and 5.7% for HEX, whereas Topcon's software provided an error of 7.5% for ECD, 17.5% for CV, and 18.3% for HEX. Our method was significantly better than Topcon's (P < 0.0001) and was not statistically significantly different from the manual assessments (P > 0.05). At month 12, the subjects presented an average ECD = 1377 ± 483 [cells/mm2], CV = 26.1 ± 5.7 [%], and HEX = 58.1 ± 7.1 [%].

Conclusions

The proposed method obtains reliable and accurate estimations even in challenging specular images of pathologic corneas.

Translational Relevance

CV and HEX, not currently used in the clinic owing to a lack of reliability in automatic methods, are useful biomarkers to analyze the postoperative healing process. Our accurate estimations allow now for their clinical use.

Intraocular lens power calculation following laser refractive surgery

Refractive outcomes following cataract surgery in patients that have previously undergone laser refractive surgery have traditionally been underwhelming. This is related to several key issues including the preoperative assessment (keratometry) and intraocular lens power calculations. Peer-reviewed literature is overwhelmed by the influx of methodology to manipulate the corneal or intraocular lens (IOL) powers following refractive surgery. This would suggest that the optimal derivative formula has yet been introduced. This review discusses the problems facing surgeons approaching IOL calculations in these post-refractive laser patients, the existing formulae and programs to address these concerns. Prior published outcomes will be reviewed.