An 11-Year Review of Keratoplasty in a Tertiary Referral Center in Turkey: Changing Surgical Techniques for Similar Indications

Penetrating Keratoplasty: Indications and Graft Survival by Geographic Region

Corneal transplantation, or penetrating keratoplasty (PK), is the most common form of solid-organ transplantation performed worldwide. Here, we evaluated the indications for PK and rates of transplant survival around the world by geographic region. We conducted a literature search of PubMed, MEDLINE, and Google Scholar databases and identified 155 relevant studies from 41 countries published between 1987 and 2021. The most common indications for PK were keratoconus in Europe, Africa, the Middle East, Australia, New Zealand, and Central and South America, bullous keratopathy in North America, and corneal scarring in Asia. The overall global mean graft survival rates at 1-, 2-, 3-, 5-, and 10-years were 88.6%, 81.2%, 78.9%, 72.8%, and 61.2%, respectively. Through this systematic analysis of PK by region, we hope to bring a new perspective to the corneal transplantation literature and to potentially highlight global differences and unmet needs in patient care.

Trends in Corneal Transplantation in a Tertiary Hospital in Brazil

PURPOSE

The purpose of this study was to analyze the evolving trends of surgical techniques and indications of corneal transplantation (CT) at a tertiary hospital in Brazil.

METHODS

The medical records of all patients who underwent CT at the Hospital Oftalmológico de Sorocaba (Sorocaba Eye Hospital) from the Banco de Olhos de Sorocaba (Sorocaba Eye Bank) group in Sorocaba, Brazil, from January 1, 2012, to December 31, 2019, were analyzed. Data regarding age, sex, transplant indication, and surgical technique were collected.

RESULTS

A total of 16,250 CTs were performed. There was a statistically significant decreasing trend of keratoconus-related CT ( P < 0.0001), with rates dropping from 41.7% among all CTs in 2012 to 25.5% in 2019. Penetrating keratoplasty, anterior lamellar keratoplasty, and endothelial keratoplasty (EK) accounted for 59.3%, 27.1%, and 7.8% of the CTs performed in 2012 and 33.3%, 16.4%, and 39.9% in 2019, respectively. A statistically significant decreasing trend was observed for penetrating keratoplasty ( P < 0.0001) and anterior lamellar keratoplasty ( P < 0.0001), whereas EK showed a statistically significant increasing trend during the period ( P < 0.0001). Among EKs, Descemet membrane EK increased statistically significantly from 12.8% in 2012 to 74.4% in 2019 ( P < 0.0001).

CONCLUSIONS

This study shows relevant evolving trends in indications and preferred CT techniques in a tertiary hospital in Brazil.

Analysis of 23 Years of Cornea Donor Data From an Eye Bank in Turkey

OBJECTIVES

We evaluated 23 years of data for cornea donors at the Istanbul Faculty of Medicine Lions Eye Bank.

MATERIALS AND METHODS

Annual statistics of corneal donors between 1996 and 2019 were reviewed retrospectively. Records for 2008 and previous years were compared with records for 2009 and years thereafter,to assess donor demographics and reasons for discard of corneas.

RESULTS

A total of 3849 corneas were obtained from 2018 donors during a 23-year period. Of these, 26 donors (11.2%) were registered, whereas 1792 (88.8%) did not register any decision for donation. There were 210 (5.46%) corneas discarded for positive serology and 291 (7.56%) for unsuitable tissue morphology, and 3348 (86.98%) corneas were determined to be suitable for transplant. For the cause of death in 2009 and subsequent years, the incidence of trauma was lower (P = .001) compared with the years previous to 2009, whereas incidence of cardiac pathology (P = .014) was higher. The number of donors older than 50 years was higher for 2009 and years thereafter, compared with data from earlier years (P = .024). The rate of discarded corneas for unsuitable tissue morphology (P = .004) and total discarded corneas (P = .027) decreased in 2009 and years thereafter. The rate of discarded corneas for HIV was higher after for 2009 and years thereafter (P = .047), whereas the rate of discarded corneas for syphilis was significantly higher for 2015 and years thereafter (P = .001).

CONCLUSIONS

This study evaluated the most extensive eye bank data in Turkey and found that advances in lamellar surgery techniques and improvements in specular microscopic facilities have expanded the pool for cornealtransplants to include tissues from older donors. Moreover, the incidence rates for HIVpositive and syphilis-positive serology tests in discarded corneas have increased over time.

Trends in Corneal Transplantation and Characteristics of Donors in the Chongqing Eye Bank, China: A Retrospective Study, 1999-2018

Aim: This study aimed to analyze corneal transplantation trends and voluntary donor characteristics at the Chongqing Eye Bank in China.

Methods: We retrospectively reviewed and analyzed data from January 1, 1999, to December 31, 2018, covering 5,397 preregistered voluntary donors, 1,955 actual donors, 3,910 donated tissues, and 2,374 corneal transplantations.

Results: The 5,397 preregistered donors included 13 ethnic groups, with an overall mean age of 39.6 years (SD 21.5) and 3,010 were women (55.8%). The most prevalent education level was college and above (2,546, 47.2%), and the most common ethnic group was Han (5,335, 98.85%). Of the 1,955 actual donors, the male-to-female ratio was 3.3, and the mean age was 57.1 (SD 23.0 years). Based on population size in 2018, Jiangbei county was the most active in donation willingness, with ~60 × 10⁻⁶ per capita, and the Yuzhong county was the most active in cornea donations, with ~451 × 0⁻⁶ per capita. Of the 3,910 donated corneas, 2,540 (65.0%) were clinically used. Of those not used, 978 (71.4%) were rejected for poor corneal quality. The 2,374 (93.5%) corneal transplantation procedures were done at the Department of Ophthalmology of the First Affiliated Hospital of Chongqing Medical University and the rest (n = 166, 6.5%) were performed in other centers. Of those 2,374 corneal transplantations, there were 1,671 penetrating keratoplasty (70.39%), 700 anterior lamellar keratoplasty (29.49%), and three corneal endothelial transplantations in our center (0.13%). The number of annual corneal transplantations increased by nearly 10 times, from 35 cases in 1999 to 327 cases in 2018. Among them, cases of penetrating keratoplasty and anterior lamellar keratoplasty increased from 27, and eight cases in 1999 to 230 and 94 cases in 2018, respectively. Infectious keratitis (37.0%) was the leading indication for keratoplasty, followed by corneal scar (19.8%). Over the study period, corneal scars dropped from the first (41.1% in 1999–2003) to the second indication (20.5% in 2014–2018), while infectious keratitis advanced to take the lead, ranging from 12.2% in 1999–2003 to 26.3% in 2014–2018.

Conclusion: Our study reports corneal donation and transplantation trends in Chongqing over 20 years, showing that infectious keratitis is a leading indication for keratoplasty and that penetrating keratoplasty and anterior lamellar keratoplasty show upward trends. The analysis further suggests that a potential preregistered cornea donor is a female Han, with a higher education level.

Changing Indications for Corneal Transplantations in Southern Taiwan From 2008 to 2018

OBJECTIVES

To investigate the changing indications for corneal transplantations in southern Taiwan from 2008 to 2018 and compare the results with those of other previous studies.

METHODS

We retrospectively reviewed the records of patients who underwent corneal transplantations from January 2008 to December 2018 at Kaohsiung Veterans General Hospital. The patients' age, sex, indication for corneal transplantation, and the surgical technique were recorded and analyzed.

RESULTS

In total, 336 patients (421 eyes) were included in our study from January 1, 2008, to December 31, 2018. The mean age was 63.6±15.3 years; 371 penetrating keratoplasty (88.1%), 35 deep anterior lamellar keratoplasty (8.3%), and 15 Descemet-stripping automated endothelial keratoplasty (3.6%) were performed. The leading indication for corneal transplantation was regraft (n=103, 24.5%), followed by bullous keratopathy (n=82, 19.5%), corneal scar and opacity (n=79, 18.8%), keratitis (n=59, 14.0%), corneal dystrophy (n=58, 13.8%), other indications (n=26, 6.2%), and keratoconus (n=14, 3.3%).

CONCLUSION

The indications for corneal transplantations changed with time in Taiwan. Regraft was the leading indication, but there was a decreasing trend over time. The proportion of bullous keratopathy increased significantly over the past decade and is the second most common indication, similar to the most developed countries. Both corneal scar and opacity, and keratitis showed a decreasing trend of occurrence compared with a previous study in Taiwan. The proportion of keratoconus remained low, making it the least common indication for corneal transplantation.

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

PURPOSE

To characterize trends in procedures, and indications for corneal transplantation over 27 years in a single referral center in Japan.

STUDY DESIGN

Retrospective study.

METHODS

Data from a consecutive series of corneal transplant surgery cases performed from 1991 to 2017at Ichikawa General Hospital were collected. The surgical procedures, indications, and causes of corneal endothelial dysfunction were evaluated.

RESULTS

Among 6,025 transplantations, a total of 3,991 cases underwent penetrating keratoplasty (PKP), 1009 underwent (deep) anterior lamellar keratoplasty, 746 underwent endothelial keratoplasty, and 309 underwent epithelial transplantation. Over that period the frequency of PKP decreased, whereas the frequency of lamellar keratoplasty increased. The four major surgical indications were bullous keratoplasty (BK 30.0%), regraft (24.2%), post-keratitis scars (17.1%), and keratoconus (11.4%). After dividing the study period into four time periods, we found that BK and regraft increased (from 20.3% to 34.5% and 18.2% to 31.1%, respectively), whereas post-keratitis scars and keratoconus decreased (from 26.0% to 9.5% and 14.1% to 7.2%, respectively) between the first and last period. Pseudophakic or aphakic BK were the major causes of corneal endothelial dysfunction until 2010. Cases of laser-iridotomy-induced BK peaked in 35 eyes (34.3% of BK) in 2000 and declined after 2013. Cases of Fuchs endothelial corneal dystrophy increased from 0 in 1991, to 15 eyes (18.5% of BK) in 2017.

CONCLUSION

Lamellar keratoplasty has replaced PKP in our hospital. BK and regraft have increased, whereas post-keratitis scars and keratoconus have decreased. Laser-iridotomy-induced BK has decreased during the past decade, whereas Fuchs endothelial corneal dystrophy has increased.

Outcomes of Descemet Membrane Endothelial Keratoplasty in Bangkok, Thailand

Purpose

To investigate the medium-term clinical outcomes and risk factors for primary graft failure after Descemet membrane endothelial keratoplasty (DMEK) in Thai patients.

Patients and Methods

This is a single-center retrospective cohort study. Sixty-two eyes of 62 patients who underwent DMEK at Ramathibodi Hospital, Bangkok, Thailand, with a minimum of 24-month follow-up were recruited. Preoperative donor and recipient characteristics, intraoperative data, and postoperative outcomes including best-corrected visual acuity (BCVA), graft clarity, endothelial cell density (ECD), central corneal thickness (CCT), and complications were evaluated at 1, 3, 6, 12, and 24 months after surgery.

Results

The mean age of the patients was 67.2 ± 9.9 years, and 52% were female. The mean follow-up time was 37.5 ± 11.0 months. The most common indications for DMEK were Fuchs' endothelial corneal dystrophy (FECD) (53.2%) and pseudophakic bullous keratopathy (PBK) (17.7%). Nearly half of patients had triple-DMEK. The median preoperative BCVA was 20/400. Postoperative BCVA of ≥ 20/40 was reached in 37.1% and of ≥ 20/20 in 6.5% after 1 month which increased to 54.8% and 17.7% after 3 months; and to 67.7% and 27.4% after 24 months. Endothelial cell loss (ECL) at 3, 6, 12, and 24 months was 30.5%, 33.8%, 44.4%, and 45.9%, respectively. Graft diameter was the single factor, showing a significant relationship with postoperative ECD. Most frequent postoperative complications included graft detachment (22.6%), increased IOP/glaucoma (17.7%), and primary graft failure (16.1%). In univariate analysis, death-to-operation time and the diagnosis of PBK were significantly associated with the occurrence of primary graft failure.

Conclusion

DMEK is a safe, effective, and feasible treatment for endothelial failure in Asian eyes. Careful case selection, use of relatively fresh donor tissues, and appropriate surgical techniques can prevent primary graft failure and facilitate optimal outcomes following surgery.

Indications and Techniques of Pediatric Keratoplasty in Eastern China From 2008 to 2017

PURPOSE

To explore the transition of indications and surgical techniques of pediatric keratoplasty in Eastern China in the past 10 years.

METHODS

Medical charts of 1026 pediatric patients (1059 eyes) who underwent keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2017 were retrospectively reviewed. The indications for keratoplasty and the surgical techniques were collected and analyzed.

RESULTS

A total of 634 infants (≤3 years) (661 eyes), 207 toddlers and older children (4-12 years) (211 eyes), and 185 adolescents (13-18 years) (187 eyes) were included. The median age at the time of surgery was 2 years. The surgical indications were composed of congenital abnormalities (74.6%), acquired nontraumatic diseases (16.5%), acquired traumatic diseases (3.6%), and regraft (5.3%). Only congenital abnormality had a significant growing trend during this decade (P = 0.023). Keratoconus (67.2%) exceeded infectious keratitis (14.9%) and was the most common acquired nontraumatic cause in our study. The annual number of pediatric keratoplasties increased significantly from 40 cases in 2008 to 190 cases in 2017 (P < 0.001). Although penetrating keratoplasty was performed in 414 eyes (39.1%), its application in the treatment of keratoconus decreased significantly during this decade (P = 0.04). By contrast, deep anterior lamellar keratoplasty showed an increasing trend because of its popularization in the treatment of keratoconus (P = 0.003).

CONCLUSIONS

Congenital abnormalities have replaced infectious keratitis and have been the leading indications of pediatric keratoplasty in the past 10 years. Although the using of penetrating keratoplasty was still the predominant procedure to treat pediatric corneal pathologies, the adoption of deep anterior lamellar keratoplasty showed a significant increasing trend during the past decade.

Recent Surgical Trends in Pediatric Corneal Transplantation: A 13-Year Review

PURPOSE

Corneal transplantation is the standard of care for pediatric corneal opacities, but little consensus exists on optimal surgical management. Our goal was to evaluate cross-sectional data of donor and recipient characteristics collected from eye banks providing tissue for pediatric corneal transplant cases to assess surgical trends in pediatric keratoplasty over the past 13 years.

METHODS

We performed a retrospective review of recipient data, collected from 4 major eye banks, for pediatric patients (<18 years) who underwent corneal transplantation between January 2005 and December 2017. We analyzed trends in surgical indications, types of keratoplasty, and donor/recipient characteristics.

RESULTS

Our database included 2620 total pediatric cases. Penetrating keratoplasty (PKP) remains the most common surgery performed (79.8%), but more partial-thickness transplant cases [eg, endothelial keratoplasty (EK)] have been performed since 2008. The most commonly reported transplant indication was ectasias/thinnings (34.1%) overall and congenital opacities (17.0%) in children less than 5 years. Average donor age was significantly lower for the youngest recipient age group of less than 5 years (P < 0.001); endothelial cell count was also higher, and death-to-surgery time was lower for PKP and EK cases versus other keratoplasties.

CONCLUSIONS

Indications for transplant vary across age groups but are consistent with previous reports. Popularity of partial-thickness transplants has increased since 2008. Surgeons prefer younger donor tissue for younger patients and have higher thresholds for endothelial cell count for PKP and EK cases. Centralized tracking of pediatric keratoplasty cases is necessary for further investigation of long-term outcomes.

Indications and techniques of corneal transplantation in a referral center in Colombia, South America (2012-2016)

PURPOSE

To describe the indications and techniques of corneal grafting in a tertiary institution in a middle-sized city in Colombia.

METHODS

A retrospective review of surgical reports and medical records of patients undergoing keratoplasty from January 2012 to December of 2016.

RESULTS

A total of 346 eyes from 316 patients were included. The first three indications for keratoplasty were: bullous keratopathy (BK) with 46.2% of the cases, active infectious keratitis (22.3%) and the group of corneal dystrophies and degenerations, including Fuchs' endothelial dystrophy (9%). Keratoconus was in the sixth place (4.9%). 73.3% of the procedures were penetrating keratoplasties (n = 255), 21.7% posterior lamellar (n = 75) and 3.5% anterior lamellar (n = 12). While in 2012, 25 cases of endothelial grafts were performed, only 13 were done in 2016.

CONCLUSIONS

BK was the first cause of keratoplasty with almost half of the cases, and keratoconus was relegated to sixth place with less than 5%. In comparison, in a study from eye banks from the US, BK was the second and keratoconus was the third indication for corneal grafts. The frequency of endothelial lamellar techniques in our institution decreased from 2012 to 2016. This could have been related to both the long time that the patients had to be on a waiting list, which made them unsuitable candidates for this technique, due to stromal fibrosis, and to the fact that surgeons of our institution had less experience with posterior endothelial grafting than with penetrating keratoplasties.