Trends in surgical procedures and indications for corneal transplantation over 27 years in a tertiary hospital in Japan

Descemet membrane endothelial keratoplasty after cataract surgery with presbyopia-correcting intraocular lens for coexisting Fuchs endothelial corneal dystrophy and cataract

PURPOSE

To assess the outcomes of Descemet membrane endothelial keratoplasty (DMEK) staged after implantation of presbyopia-correcting intraocular lenses (IOLs) in patients with coexisting Fuchs endothelial corneal dystrophy (FECD) and cataract.

STUDY DESIGN

Retrospective, interventional case series METHODS: We enrolled six eyes of three patients with coexisting FECD and cataract (3 women, age 67.8 ± 6.5 years) treated with presbyopia-correcting IOL implantation, followed by DMEK. The modified Krachmer grade, visual outcomes, and incidence of intra- and postoperative complications were analyzed.

RESULTS

Modified Krachmer FECD grades 4, 5, and 6 were observed in one, two, and three eyes, respectively. The mean best-corrected visual acuity (BCVA) was dissatisfactory with the primary presbyopia-correcting IOL (decimal 0.45), it improved significantly (decimal 1.0, P = 0.027) after DMEK and all eyes acquired satisfactory uncorrected distance and near (30 cm) vision (mean, decimal, distance 0.85 and near 0.56). The manifest spherical equivalent after DMEK was within the acceptable range (-0.375 D to 0.0 D). Rebubbling was required in four eyes, but no instances of other postoperative complications or primary graft failure were encountered.

CONCLUSION

DMEK staged after implantation of presbyopia-correcting IOLs is a viable option for patients with coexisting FECD and cataract.

Study of a single eye bank. Characteristics and progression of corneal transplantation from 2016 through 2022 in Galicia (Spain)

OBJECTIVE

To describe the characteristics of donated and transplanted corneas, trends in surgical techniques, and indications for corneal transplantation, and the impact of COVID-19 on a Spanish tissue bank from 2016 through 2022.

METHODS

We conducted a retrospective analysis of corneal donation records from Complejo Hospitalario Universitario de A Coruña Cryobiology Unit and Tissue Bank from January 1st, 2016 through June 30th, 2022.

RESULTS

Corneal donations and transplants remained stable over 6.5 years, except for declines in 2020-2021. A total of 44.3% of all donated corneas were not transplanted, mainly due to tissue viability issues (41.4%). Donors averaged 60.2 ± 13 years, with a mean corneal endothelial cell count of 2701.3 ± 324.6 cells/mm² and a mean corneal clear zone diameter of 7.7 ± 0.7 mm. The preferred preservation method for keratoplasty was hypothermia (85,9%). Indications included endothelial dysfunction (53.8%), repeated keratoplasty (18.8%), corneal ectasia (15.4%), stromal opacity (7.6%), and tectonic causes (4.9%). Penetrating keratoplasty (PK) was more common (56.3%) than lamellar techniques (43.7%), but endothelial keratoplasty (EK) increased by 27.8% since 2019. EK, predominantly Descemet Membrane Endothelial Keratoplasty (DMEK, 94.1%), was used in 96.7% of endothelial dysfunction cases, although 28.6% were treated with PK. Deep anterior lamellar keratoplasty was primarily used for corneal ectasia (46.8%).

CONCLUSIONS

The Galicia Tissue Bank exceeds the European Eye Bank Association quality standards. Penetrating techniques remain predominant, but the trend is towards favor lamellar procedures, particularly DMEK. Endothelial dysfunction is the leading and growing indication for corneal transplantation.

Healing the cornea: Exploring the therapeutic solutions offered by MSCs and MSC-derived EVs

Affecting a large proportion of the population worldwide, corneal disorders constitute a concerning health hazard associated to compromised eyesight or blindness for most severe cases. In the last decades, mesenchymal stem/stromal cells (MSCs) demonstrated promising abilities in improving symptoms associated to corneal diseases or alleviating these affections, especially through their anti-inflammatory, immunomodulatory and pro-regenerative properties. More recently, MSC therapeutic potential was shown to be mediated by the molecules they release, and particularly by their extracellular vesicles (EVs; MSC-EVs). Consequently, using MSC-EVs emerged as a pioneering strategy to mitigate the risks related to cell therapy while providing MSC therapeutic benefits. Despite the promises given by MSC- and MSC-EV-based approaches, many improvements are considered to optimize the therapeutic significance of these therapies. This review aspires to provide a comprehensive and detailed overview of current knowledge on corneal therapies involving MSCs and MSC-EVs, the strategies currently under evaluation, and the gaps remaining to be addressed for clinical implementation. From encapsulating MSCs or their EVs into biomaterials to enhance the ocular retention time to loading MSC-EVs with therapeutic drugs, a wide range of ground-breaking strategies are currently contemplated to lead to the safest and most effective treatments. Promising research initiatives also include diverse gene therapies and the targeting of specific cell types through the modification of the EV surface, paving the way for future therapeutic innovations. As one of the most important challenges, MSC-EV large-scale production strategies are extensively investigated and offer a wide array of possibilities to meet the needs of clinical applications.

National Survey on Corneal Transplantation in Japan

PURPOSE

To report the results of a national survey on corneal transplantation in Japan.

METHODS

The Japan Cornea Society and the Keratoplasty Society of Japan conducted a national survey on corneal transplantation performed from 2017 to 2019. Data from various institutions were collected through an online database and subsequently analyzed.

RESULTS

In total, 4951 cases from 44 facilities were documented. The leading cause of corneal transplantation was corneal edema (CE), which accounted for 39.3% of cases, followed by repeat keratoplasty at 27.7%. Among CE cases, postcataract surgery was the most prevalent (25.1%), followed by postglaucoma surgery (20.8%) and laser iridotomy-induced CE (18.2%). Fuchs endothelial corneal dystrophy was the fourth most common cause (10.9%). Regarding surgical methods, Descemet stripping automated endothelial keratoplasty was the most common, used in 41.3% of procedures, followed by penetrating keratoplasty at 37.1%. Deep anterior lamellar keratoplasty and Descemet membrane endothelial keratoplasty were used in 8.1% and 2.6% of cases, respectively. One year after transplantation, graft clarity was maintained in 80.5% of cases, and regrafting was necessary in 15.2% of instances.

CONCLUSIONS

The national survey reveals that CE is the most frequent indication for corneal transplantation in Japan. Increases in cases from glaucoma surgery and Fuchs endothelial corneal dystrophy were noted among patients with CE. Endothelial keratoplasty, especially Descemet stripping automated endothelial keratoplasty, is now the preferred surgical technique for these transplants.

The progress and future of corneal endothelial transplantation

Endothelial transplantation has recently been accepted worldwide, in the long history of corneal transplantation. The introduction of endothelial keratoplasty (Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty) has enabled us to expand the surgical indications owing to the low incidence of rejection and quick recovery of visual function. New technologies have been developed to ensure stable postoperative outcomes with a shorter learning curve, such as transplantation using cultured human endothelial cells and induced pluripotent stem cells (iPS) or new devices such as artificial endothelium. This review discusses the history and characteristics of corneal transplantation alongside new treatment options that may offer hope for patients with endothelial disease in the future.

Trends in keratoplasty from central and northern India. Part II: Types of keratoplasty

PURPOSE

To report the types of keratoplasty and analyze trends over a period of two decades in central and northern India.

METHODS

This was a retrospective review of eye bank registries of six tertiary eye care centers located in central and north India from 2005 to 2021. The indications and various keratoplasty procedures were compared between 2005-2012 and 2013-2021 to analyze the trend.

RESULTS

A total of 13,223 corneal grafts were performed, of which therapeutic penetrating keratoplasty (TPK) (5719, 43.3%) was the most common procedure, followed by optical penetrating keratoplasty (OPK) (5528, 41.8%), Descemet stripping endothelial keratoplasty (DSEK) (1279, 9.7%), deep anterior lamellar keratoplasty (DALK) (376, 2.8%), Descemet membrane endothelial keratoplasty (DMEK) (215, 1.6%), patch grafts (75, 0.6%), and keratoprostheses (31, 0.2%). Overall, OPK procedures decreased (-14.1%, P < 0.001), but TPK (+3.1%, P < 0.019), DSEK (+7.1%, P < 0.001), and DMEK (+1.9%, P < 0.001) procedures increased. Although there was an increasing trend in the use of DALK (+0.8%, P < 0.083) and keratoprostheses (+0.3%, P = 0.074) procedures, the trends were not statistically significant.

CONCLUSION

In keeping with worldwide trends, an increasing trend in lamellar keratoplasties was observed in central and northern India during the past decade. The trend was significant for DSEK. However, as corneal ulcers and scars were the major indications for keratoplasty, TPK and OPK remained the most common procedures.

Trends in keratoplasty from central and Northern India. Part I: Indications for keratoplasty

PURPOSE

To report the indications for keratoplasty and analyze trends in two decades in India.

METHODS

This was a retrospective review of eye bank registries of six tertiary eye care centers located in central and northern India from 2005 to 2021. The patterns of corneal pathology and changes in trends were analyzed.

RESULTS

Between 2005 and 2021, 13223 corneal grafts were performed in the six collaborating tertiary eye care centers. The most common indication for keratoplasty in both decades was corneal ulcer (41.1%), followed by corneal scar (25.5%), failed graft (12.0%), post-cataract surgery corneal edema (11.7%), corneal dystrophies (3.1%), corneal ectasia (1.8%), corneal trauma (0.3%), congenital corneal opacity (0.3%), and others (4.1%). An increasing trend was seen in corneal ulcers, failed grafts, and keratoconus. A reducing trend was seen in corneal scar and aphakic bullous keratopathy. There was no change in pseudophakic bullous keratopathy and Fuchs endothelial corneal dystrophy.

CONCLUSION

Corneal ulcers, corneal scars, failed grafts, and post-cataract surgery corneal edema remained the foremost indications for keratoplasty in two decades in India. An increasing trend was seen in corneal ulcers and failed grafts which are of concern as these indications carry a poorer outcome. Capacity building in lamellar keratoplasty techniques is the need of the hour as pseudophakic bullous keratopathy was an important indication, and an increasing trend was noticed in keratoconus.

Clinical Evaluation of the Efficacy of Femtosecond Laser-Assisted Anterior Lamellar Keratoplasty

BACKGROUND

To evaluate the clinical outcome, efficacy, and safety of femtosecond laser-assisted anterior lamellar keratoplasty.

MATERIAL AND METHODS

In this prospective study, 21 males and 10 females aged from 15 to 62 years (mean 38.5) with different pathologies of the anterior corneal layers were enrolled for anterior lamellar keratoplasty using femtosecond laser VisuMax (Carl Zeiss, Germany). All patients were examined for uncorrected (UCVA) and best-corrected (BCVA) distance and near visual acuity, astigmatism, endothelial cell density, corneal thickness, and intraocular pressure. These examinations were performed before transplantation, at hospital discharge, and after 3 and 12 months. The mean follow-up time was 65.36 ± 28.54 months.

RESULTS

A statistically significant improvement of both UCVA and BCVA for distance and near vision was registered. BCVA improved from 0.11 preoperatively to 0.168 (p = 0.03), 0.267 (p < 0.01), and 0.472 (p < 0.01) on the hospital discharge day, three months, and 12 months respectively. There were no statistically significant differences in astigmatism, intraocular pressure, endothelial cell density, and corneal pachymetry as compared to preoperative and postoperative values. Six patients (19%) had a graft failure with a rate of 33% at 26 months.

CONCLUSIONS

Femtosecond laser-assisted anterior lamellar keratoplasty is a safe and effective surgical method, providing satisfactory graft survival rates.

The predictability of graft thickness for Descemet's stripping automated endothelial keratoplasty using a mechanical microkeratome system

Descemet's stripping automated endothelial keratoplasty (DSAEK) is used for treating corneal endothelial dysfunction, and the postoperative visual acuity outcome depends on the thickness of the graft. We created a simple nomogram using factors affecting the cutting thickness during graft preparation via a mechanical microkeratome system for DSAEK. This retrospective study was conducted from May 2018 through October 2022 and included donor eyes cut by automatic methods. We measured the graft thickness, cutting accuracy, and assessed ten variables with donor/cornea-related factors potentially affecting the cutting thickness. Subsequently, we created a simple nomogram. We analyzed 81 donor tissues, and the donor median age was 76 years. The mean central graft thickness was 122.2 μm, with 62% of the grafts that could be cut within the target central graft thickness range. Comparatively, donor corneas from those with cardiac diseases were cut deeper (P = 0.007). The developed nomogram provided a 83% probability of estimating the post-cutting graft thickness within 25 µm. Our nomogram, which considers cause of death, enables reproducible production of graft of a desired thickness. A detailed analysis of donor tissues, including the cause of donor death and the characteristics from pressurization to cutting, will enable more precise DSAEK graft preparation.

Indications and techniques of corneal transplants performed in one center in Southern Poland, in the years 2001–2020

Purpose

The study aimed to evaluate changes over a period of time in techniques and indications for corneal transplantation in a single center in Poland.

Methods

Retrospective analysis of corneal transplants performed at the Ophthalmology Department of the District Railway Hospital in Katowice in 2001–2020. Data on indications and surgical technique were collected.

Results

A total of 3021 corneal transplantations were performed in the years 2000–2020. The most common technique was penetrating keratoplasty (69,54%), then lamellar grafts—both anterior and posterior (19,63%), and limbal grafts (10,82%). Only in 2007 the number of lamellar keratoplasties exceeded the number of penetrating grafts and accounted for 108 (54,55%), including 85 (42,93%) of Descemet Stripping Automated Endothelial Keratoplasty. The only noticeable trend in changing techniques was a decrease in the number of performed deep anterior lamellar keratoplasties (r 2 = -0.21) over the last seven years. Main indications included bullous keratopathy (23,22%), following keratoconus (18,59%), leukoma (14,67%), keratitis and perforation (14,3%), Fuchs dystrophy (11,4%), and regrafts (7,22%). Leukoma and bullous keratopathy as an indications for corneal transplant have been declining over the years (r2 = 0.60 and r2 = 0.30 respectively). Consecutively, indications such as fuchs dystrophy, regraft and keratitis perforation have increased (r2 = 0.05, r2 = 0.50, r2 = 0.33)

Conclusions

The number of keratoplasties gradually increased from 2001 to 2020. It could be possible that the development and spread of new therapeutic alternatives, like corneal cross-linking and scleral lenses, have contributed to the decrease in deep anterior lamellar keratoplasty performed. There was an increasing trend in the percentage of penetrating keratoplasties for failed grafts, Fuchs dystrophy and infectious keratitis.

Donor-Related Risk Factors for Graft Decompensation Following Descemet's Stripping Automated Endothelial Keratoplasty

Aims

To identify donor-related risk factors associated with graft endothelial failure and postoperative endothelial cell density (ECD) reduction after Descemet's stripping automated endothelial keratoplasty (DSAEK).

Methods

This was a single-center retrospective study conducted from July 2006-December 2016. We included 584 consecutive eyes (482 patients) that underwent DSAEK for the treatment of laser iridotomy-related bullous keratopathy (192 eyes), pseudophakic bullous keratopathy (137 eyes), regraft (96 eyes), Fuchs' endothelial corneal dystrophy (FECD; 59 eyes) and others (100 eyes). Twenty-three donor- and recipient-related risk factors potentially associated with graft failure and ECD reduction were assessed using Cox hazard models and linear mixed effect models.

Results

The median age of the patients was 73.5 years (male; 35.6%). After DSAEK, ECD decreased from 2,674 cells/mm2 (95% confidence interval [CI]; 2,646–2,701) to 1,132 (1,076–1,190) at 12 months and 904 (845–963) at 24 months (P &lt; 0.001). Fifty-five eyes (9.4%) had graft endothelial failure without rejection. This failure was associated with donor pseudophakic lens status (hazard ratio [HR]; 2.67, CI; 1.50–4.76, P = 0.001) and preoperative endothelial folds (HR; 2.82, CI; 1.20–6.62, P = 0.02). The incidence of graft endothelial failure in non-FECD patients was significantly higher among those receiving donor grafts with a pseudophakic lens status and preoperative presence of endothelial folds (P &lt; 0.001). Postoperative ECD loss was significantly greater in eyes with these risk factors compared to those without (P = 0.007).

Conclusions

Pseudophakic status and/or presence of preoperative endothelial folds are the significant donor risk factors for endothelial failure in non-FECD patients.