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

Repeat corneal transplantation in Southern China: Indications, surgical technique, outcomes, and risk factors for repeat keratoplasty failure

PURPOSE

To report the indications, surgical techniques, and outcomes of repeat keratoplasty and evaluate the risk factors for graft failure in the Chinese population.

METHODS

The medical records of 216 patients (243 cases) who underwent at least two keratoplasties at a leading eye hospital in southern China between 2011 and 2020 were retrospectively reviewed. Indications and surgical procedures for repeat corneal transplantation were analyzed. Kaplan-Meier survival analysis was used to determine the graft survival rate after repeat keratoplasty. A multivariable survival model was used to assess the risk factors.

RESULTS

Repeated keratoplasties increased continuously from 2011 to 2020 (P = 0.002). The most common primary indication was infectious keratitis (38.7%), and the most common reason for repeat keratoplasty was graft rejection (30.04%). Regraft techniques included penetrating keratoplasty (PK) in 165 cases (67.9%), deep lamellar keratoplasty (DALK) in 52 cases (21.40%), and endothelial keratoplasty (EK) in 26 cases (10.7%). Median survival was 5.3, 6.8, and 6.4 years for PK, DALK, and EK, respectively. The 5-year survival rate was 53.5%, 66.6%, and 69.8% for PK, DALK, and EK, respectively. The median LogMAR visual acuity was 1.4 for PK, 0.75 for DALK, and 1.2 for EK at the end of the follow-up. Multivariate analysis revealed that graft rejection is a risk factor for repeat keratoplasty failure (P = 0.002).

CONCLUSIONS

DALK and EK may provide better outcomes than PK in treating graft failure. Preventing and treating postoperative graft rejection may be key to improving regraft survival. These findings will aid in the management of failed corneal grafts.

Graft rejection episodes after keratoplasty in Japanese eyes

We aimed to investigate the clinical characteristics and risk factors for graft rejection after keratoplasty in Japanese patients. We enrolled 730 cases (566 patients) of penetrating keratoplasty (PK, N = 198), Descemet's stripping automated endothelial keratoplasty (DSAEK, N = 277), non-Descemet's stripping automated endothelial keratoplasty (nDSAEK, N = 138), and Descemet membrane endothelial keratoplasty (DMEK, N = 117). The incidence, clinical characteristics, and possible risk factors for graft rejection were analyzed. Graft rejection occurred in 65 cases (56 patients, 8.9%). The incidence rate of rejection was highest with PK (3.45/100 person-years), followed by DSAEK (2.34), nDSAEK (1.55), and DMEK (0.24). Cox regression analysis revealed keratoplasty type, younger age, indications (such as failed keratoplasty and infection), and steroid eyedrop use as possible risk factors. In the multivariate model adjusting baseline characteristics, PK and DSAEK had significantly higher hazard ratios (HRs) than DMEK (HR = 13.6, 95% confidence interval [CI] [1.83, 101] for PK, 7.77 [1.03, 58.6] for DSAEK). Although not statistically significant, the HR estimate of nDSAEK to DMEK (HR = 7.64, 95% CI [0.98, 59.6]) indicated higher HR in nDSAEK than in DMEK. DMEK is the favorable option among the four surgical procedures to avoid graft rejection after keratoplasty.

Trends in Keratoplasty Procedures During 2 Decades in a Major Tertiary Referral Center in Finland: 1995 to 2015

PURPOSE

The purpose of this study was to analyze trends in number, age-adjusted frequency, and type of keratoplasty in a major tertiary referral center, relative to patient and graft characteristics.

METHODS

A retrospective registry study of 1574 patients who in 1995 to 2015 underwent keratoplasty in the Helsinki University Eye Hospital (HUEH). Graft type and sequence, patient characteristics, and date of surgery were recorded. Main outcome measures were annual number, type, and age-adjusted frequency of keratoplasty; patient and graft characteristics; graft procurement; and national population-adjusted frequency of keratoplasty.

RESULTS

In HUEH, from 1995 to 2015, a total of 2191 keratoplasties were performed with 48% of the grafts procured intramurally; 76% were primary and 24% regrafts. The age-adjusted frequency of primary penetrating keratoplasty decreased by 52% from 0.96 to 0.46 per 100,000. The corresponding frequency of primary Descemet stripping automated endothelial keratoplasty increased by 367% from 0.3 to 1.4 after 2006, finally accounting for 68% of primary grafts. Men underwent primary penetrating keratoplasty (median 48 vs. 67 yrs, P = 0.0001) and anterior lamellar keratoplasty (median 37 vs. 46 yrs, P = 0.0015) at a younger age than women. Interval to the first regraft was comparable between sexes (median 2.2 vs. 1.9 yrs, respectively, P = 0.17). The national median population-adjusted frequency of keratoplasties was 3.2 per 100,000 from 2009 to 2015, and HUEH accounted for a median of 69% of them.

CONCLUSIONS

The increased frequency of keratoplasty in HUEH resulted from rapid adoption of Descemet stripping automated endothelial keratoplasty after 2006 and was facilitated by centralizing graft procurement to HUEH and the National Cell and Tissue Center Regea.

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.

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.

Intraoperative optical coherence tomography-guided nanothin Descemet stripping automated endothelial keratoplasty in a patient with a remarkably thickened cornea

Purpose

To report use of intraoperative optical coherence tomography (OCT) for nanothin Descemet stripping automated endothelial keratoplasty (DSAEK) in a patient with an extremely thickened cornea due to advanced bullous keratopathy.

Observations

A 90-year-old woman with a history of multiple trabeculectomies was referred to us for treatment of advanced bullous keratopathy (1400 μm central corneal thickness). Nanothin DSAEK was planned and performed. In brief, after the removal of the loose corneal epithelium, the anterior chamber was meticulously observed using a surgical microscope and oblique light via an endoillumination probe; however, the visibility of the anterior chamber was limited because of severe corneal edema. Subsequently, a nanothin (47 μm) DSAEK graft stained with trypan blue was inserted into the anterior chamber using an NS endoinserter. Intraoperative OCT was used successfully to visualize the graft unfolding, air tamponade, and graft attachment. At 3 months postoperatively, significant corneal clearing (625 μm central corneal thickness), improvement of visual acuity (decimal 0.04), and pain relief were obtained.

Conclusions and importance

Intraoperative OCT is useful for nanothin DSAEK even when the surgical microscope view is compromised by a remarkably thickened host cornea due to advanced bullous keratopathy. As an alternative to a penetrating keratoplasty, less invasive nanothin DSAEK was successfully performed.

Risk factors for keratoconus progression after treatment by accelerated cross-linking (A-CXL): A prospective 24-month study

PURPOSE

Identification of potential predictive factors for keratoconus progression after treatment by accelerated Cross-linking (A-CXL) SECONDARY OBJECTIVES: Evaluation of clinical and topographic outcomes for two years following accelerated cross-linking treatment for progressive keratoconus including: best spectacle corrected visual acuity (BSCVA), thinnest pachymetry, maximum keratometry (Kmax), cylinder.

STUDY

Prospective, interventional, monocentric study. SITE: Metz-Thionville Regional Medical Center, Lorraine University, Mercy Hospital, Metz, France.

PATIENTS AND METHODS

We included 82 eyes of 60 patients between March 2014 and June 2016 who underwent accelerated corneal cross-linking (A-CXL) with epithelial debridement for progressive keratoconus, with a minimum follow-up of 2 years. A complete clinical evaluation and corneal topography were performed before cross-linking, and subsequently at 6, 12 and 24 months post-procedure. The following parameters were monitored during follow-up: best spectacle corrected visual acuity (BSCVA), minimal pachymetry, maximum keratometry (Kmax), mean anterior and posterior curvatures, maximum posterior curvature, presence of optical aberrations, subdivided into spherical aberration, coma, astigmatism, higher order optical aberrations and residual optical aberrations. After a 2-year follow-up, two groups, defined as "responders" and "non-responders" to treatment, were separated for analysis, and their initial characteristics were compared.

RESULTS

Data for 82 eyes of 60 patients with progressive keratoconus with a mean age of 24±7 years were studied. Fourteen eyes (17.1%) showed signs of progression after treatment by A-CXL (non-responders), and 68 eyes (82.9%) showed stabilization of the disease (responders). Characteristics of non-responding eyes after A-CXL included a younger mean age (20±5 vs. 25±7 years) (P=0.04) and a lower initial mean BCVA for non-responders of 0.44±0.16 logMAR vs. 0.29±0.19 logMAR (P=0.03). Non-responders also had a higher mean maximal posterior curvature (AKB) of -10.84±1.72D vs. -9.46± 1.12D (P=0.03). They also showed more higher order optical aberrations (3.84±1.72D vs. 2.4±1.02D; P=0.01), including coma (3.85±1.81D vs. 2.1±1.01D; P=0.03) and more residual aberrations than responders (1.05±0.44D vs. 0.45±0.6D; P=0.005). No significant differences were found between responders and non-responders for the other parameters in our study.

CONCLUSION

Eyes with progressive keratoconus who did not respond to A-CXL treatment were the most aggressive cases in the youngest patients, with highest maximum corneal curvatures and most pronounced optical aberrations. These patients should be informed in advance of the high risk of non-response to A-CXL treatment, and of the potential need for additional treatment in the future.

Changing Indications for Penetrating Keratoplasty in Bahrain in a Tertiary Referral Centre

PURPOSE

To study the changing indications for Penetrating keratoplasty in Bahrain and to compare them with published data.

PATIENTS AND METHODS

A Retrospective review of available records of patients who underwent penetrating keratoplasty at a tertiary center in Bahrain (1996-2015). The trend of each indication was analyzed. The study was subdivided into three periods for correlation purposes. Pearson Coefficient r and the p values were used for interpretation of data. The results were compared with similar studies.

RESULTS

A total of 298 patients underwent keratoplasty in the study period, which is from 1996 until 2015 (missing data 2009-2011). Keratoconus was found to be the leading indication, accounting for 33% of the total cases, followed by trachoma 27%, followed by aphakic and pseudophakic bullous keratopathies 13%. Trachoma showed a statistically significant decreasing trend (p < 0.001), Keratoconus had an increasing trend (p<0.001). Bullous keratopathy showed an increasing trend (p = 0.001) with an abrupt rise after 2012.

CONCLUSION

Corneal scarring due to old trachoma was the leading indication for keratoplasty 20 years ago in Bahrain. However, due to improvement of health awareness, hygiene, and the socioeconomic status, this has regressed with keratoconus becoming the leading indication from 2002 onwards. A surge of bullous keratopathy was noted after 2012, placing it as the second commonest indication. This may be due to the introduction of phacoemulsification technique for cataract surgery, and perhaps because the nature of the institute being a teaching hospital. Keratoconus is the leading indication and showed an increasing trend. It is recommended to perform a keratoconus screening program for early detection and prevention.

Current development of alternative treatments for endothelial decompensation: Cell-based therapy

Current treatment for corneal endothelial dysfunction consists in the replacement of corneal endothelium by keratoplasty. Owing to the scarcity of donor corneas and the increasing number of transplants, alternative treatments such as cell-based therapies are necessary. In this article, we highlight the biological aspects of the cornea and the corneal endothelium, as well as the context that surrounds the need for new alternatives to conventional keratoplasty. We then review some of those experimental treatments in more detail, focusing on the development of the in vitro and preclinical phases of two cell-based therapies: tissue-engineered endothelial keratoplasty (TE-EK) and cell injection. In the case of TE-EK graft construction, we analyse the current progress, considering all the requirements it must meet in order to be functional. Moreover, we discuss the inherent drawbacks of endothelial keratoplasties, which TE-EK grafts should overcome in order to make surgical intervention easier and to improve the outcomes of current endothelial keratoplasties. Finally, we analyse the development of preclinical trials and their limitations in terms of performing an optimal functional evaluation of cell-based therapy, and we conclude by discussing early clinical trials in humans.

Graft Edge Reflection of a Tightly Scrolled Roll Using Endoillumination as a Simple Method for Determining Graft Orientation in Descemet Membrane Endothelial Keratoplasty

PURPOSE

To describe a simple finding that can be used to determine donor tissue orientation in Descemet membrane endothelial keratoplasty (DMEK). This involves the appearance of a highly reflective round curved line from an overlapping graft edge within the anterior chamber using light from an endoilluminator. We here name this Kobayashi sign (K-sign).

METHODS

Twelve consecutive eyes from 12 patients who underwent DMEK were evaluated for the presence of a K-sign. The presence of Berrospi sign (B-sign), a double-line reflection from the peripheral curls of the Descemet membrane (DM) roll that has been reported to be useful for correct graft orientation, was also evaluated.

RESULTS

Of 12 cases, 3 donors showed a loosely scrolled roll soon after DM donor insertion; all 3 of these showed a positive B-sign only when the endoilluminator was used. Nine donors showed a tightly scrolled DM roll without a B-sign; among these 9 donors, a K-sign was visible in 7 cases only when the endoilluminator was used. The remaining 2 cases with a tight scroll configuration showed no K-sign even with the use of endoillumination, indicating that the roll edge was located completely downward; rotation of the roll using a small jet of fluid from paracentesis revealed K-sign in these cases.

CONCLUSIONS

This technique is useful for determining the correct orientation of a tightly scrolled DM roll, subsequently enabling rapid DMEK surgery. For loosely scrolled DM roll, endoillumination enhanced B-sing is proven useful.

<p>Visibility of the Retina Through an Air-Filled Anterior Chamber During Simultaneous Vitrectomy and Descemet’s Stripping Automated Endothelial Keratoplasty</p>

Purpose

Methods

Results

Conclusion