The CORTES Study

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.

Host Defense Peptides at the Ocular Surface: Roles in Health and Major Diseases, and Therapeutic Potentials

Sight is arguably the most important sense in human. Being constantly exposed to the environmental stress, irritants and pathogens, the ocular surface – a specialized functional and anatomical unit composed of tear film, conjunctival and corneal epithelium, lacrimal glands, meibomian glands, and nasolacrimal drainage apparatus – serves as a crucial front-line defense of the eye. Host defense peptides (HDPs), also known as antimicrobial peptides, are evolutionarily conserved molecular components of innate immunity that are found in all classes of life. Since the first discovery of lysozyme in 1922, a wide range of HDPs have been identified at the ocular surface. In addition to their antimicrobial activity, HDPs are increasingly recognized for their wide array of biological functions, including anti-biofilm, immunomodulation, wound healing, and anti-cancer properties. In this review, we provide an updated review on: (1) spectrum and expression of HDPs at the ocular surface; (2) participation of HDPs in ocular surface diseases/conditions such as infectious keratitis, conjunctivitis, dry eye disease, keratoconus, allergic eye disease, rosacea keratitis, and post-ocular surgery; (3) HDPs that are currently in the development pipeline for treatment of ocular diseases and infections; and (4) future potential of HDP-based clinical pharmacotherapy for ocular diseases.

Survival Outcome and Prognostic Factors of Corneal Transplantation: A 15-Year Retrospective Cohort Study at King Chulalongkorn Memorial Hospital

Purpose

To evaluate long-term survival outcomes and determine the prognostic factors of corneal transplantation performed at a tertiary referral hospital in Thailand.

Design

A 15-year retrospective cohort study.

Materials and Methods

One corneal graft per patient was selected; graft failure was defined as graft opacity due to recurrent disease or endothelial cell dysfunction. Kaplan–Meier survival analysis was performed. Median time to failure was compared using the Log rank test. Prognostic factors were identified using the Cox proportional hazards model.

Results

We enrolled 704 transplanted grafts. Surgical indications were optical (88.5%), therapeutic (10.2%), and tectonic (1.3%). The most common diagnoses were corneal opacity (25.3%), bullous keratopathy (15.8%), and regraft (14.8%). The overall survival rates at 1, 3, 5, and 10 years were 87.5%, 72.0%, 59.2%, and 41.7%, respectively. Univariate analysis identified age, primary diagnosis, graft size, pre-existing glaucoma, prior lens status, prior intraocular surgery, indication for surgery, donor endothelial cell density, and previous graft rejection as prognostic factors for graft failure. Multivariate analysis revealed three prognostic factors: primary diagnosis of perforation/peripheral ulceration/Mooren’s ulcer (hazard ratio [HR]=28.57; 95% confidence interval [CI], 6.32–129.16; P<0.001), active keratitis (HR=24.30; 95% CI, 5.88–100.43; P<0.001), regraft (HR=9.37; 95% CI, 2.27–38.66; P=0.002), and pseudophakic/aphakic bullous keratopathy (HR=7.97; 95% CI, 1.93–32.87; P=0.004); pre-existing glaucoma (HR=1.52; 95% CI, 1.13–2.04; P=0.006); and previous graft rejection (HR=1.95; 95% CI, 1.54–2.48; P<0.001).

Conclusion

Overall corneal graft survival rate was high in the first postoperative year and decreased after that. Primary diagnosis, pre-existing glaucoma, and previous graft rejection negatively influenced graft survival.

Prevalence and risk factors to develop ocular hypertension and glaucoma after penetrating keratoplasty

OBJECTIVE

To determine the prevalence and factors associated with the development of ocular hypertension and glaucoma, in patients undergoing penetrating keratoplasty, in the Eye Clinic of the city of Bogotá.

METHOD

A retrospective cross-sectional study was conducted, and 130 eyes of patients undergoing penetrating keratoplasty were analyzed at the Eye Clinic in Bogotá, between January 2015 and August 2018. Demographic and clinical data were obtained, and it was determined by bivariate analysis, the association factors and the prevalence of the pathology under study.

RESULTS

Prevalence of ocular hypertension was 27.69% and glaucoma 10%. Average age 48.93 ± 18.63 years; higher frequency of presentation in men (61.5%). Statistically significant association factors were male sex (PR 2.59), presence of peripheral anterior synechiae (PR 1.83), history of trauma (PR 2.16), prior PK (PR 2.10) and graft failure (PR 2.04). Post-KP glaucoma only had statistically significant association with bullous keratopathy (PR 2.76).

CONCLUSIONS

Ocular hypertension and glaucoma had a high prevalence after penetrating keratoplasty, and the association factors were similar to those reported in other international studies. Knowing these factors, allows focusing surveillance and treatment in these patients to avoid blindness due to damage of the optic nerve or corneal graft.

Corneal transplantation activity in Catalonia, Spain, from 2011 to 2018: Evolution of indications and surgical techniques

Purpose

To report corneal transplant activity carried out in Catalonia (Spain) and the evolving indications for keratoplasty over an 8-year period.

Methods

Annual reports from the Catalan Transplant Organization, Spain, on corneal graft indications and techniques from 2011 to 2018 were reviewed.

Results

A total of 9457 keratoplasties were performed in Catalonia, from January 2011 to December 2018. The most frequent indications were bullous keratopathy (BK; 20.5%), Fuchs endothelial dystrophy (FED; 17.9%), re-graft (13.7%), and keratoconus (11.3%). Penetrating keratoplasty (PKP) accounted for 63.4% of all performed keratoplasties. Since the introduction of eye bank precut tissue for Descemet stripping automated endothelial keratoplasty (DSAEK) in 2013 and for Descemet membrane endothelial keratoplasty (DMEK) in 2017 the number of endothelial keratoplasties has drastically increased. An increasing trend of posterior lamellar techniques over the total of keratoplasties was found (p<0.001). Endothelial keratoplasties for different endothelial diseases indications (BK, FED, and re-graft), also showed and increasing trend (p<0.001). DMEK is the technique with the highest increase (statistically significantly different from linearity) over other endothelial keratoplasties in FED (p<0.001) but not in BK (p = 0.67) or re-grafts (p = 0.067).

Conclusion

Endothelial diseases represented the top indication for keratoplasty over the 8-year period. PKP is still the most used technique in Catalonia, but endothelial keratoplasties and especially DMEK showed a significant increasing trend over the last years. This is congruent with the main rationale nowadays for keratoplasties: to customize and transplant as less tissue as possible. Therefore, the availability of precut tissue could have definitely enforced such approach.

Prevalence and risk factors to develop ocular hypertension and glaucoma after penetrating keratoplasty

OBJECTIVE

To determine the prevalence and factors associated with the development of ocular hypertension and glaucoma, in patients undergoing penetrating keratoplasty, in the Eye Clinic of the city of Bogotá.

METHOD

A retrospective cross-sectional study was conducted, and 130 eyes of patients undergoing penetrating keratoplasty were analyzed at the Eye Clinic in Bogotá, between January 2015 and August 2018. Demographic and clinical data were obtained, and it was determined by bivariate analysis, the association factors and the prevalence of the pathology under study.

RESULTS

Prevalence of ocular hypertension was 27.69% and glaucoma 10%. Average age 48.93 ± 18.63 years; higher frequency of presentation in men (61.5%). Statistically significant association factors were male sex (PR 2.59), presence of peripheral anterior synechiae (PR 1.83), history of trauma (PR 2.16), prior PK (PR 2.10) and graft failure (PR 2.04). Post-KP glaucoma only had statistically significant association with bullous keratopathy (PR 2.76).

CONCLUSIONS

Ocular hypertension and glaucoma had a high prevalence after penetrating keratoplasty, and the association factors were similar to those reported in other international studies. Knowing these factors, allows focusing surveillance and treatment in these patients to avoid blindness due to damage of the optic nerve or corneal graft.

Indications, surgical procedures and outcomes of keratoplasty at a Tertiary University-based hospital: a review of 10 years' experience

OBJECTIVE

To investigate keratoplasty outcomes in a university-based hospital.

METHODS

Medical records of all patients undergoing keratoplasty at King Abdulaziz University Hospital, Riyadh, Saudi Arabia, between January 1, 2006, and December 31, 2015, with a minimum follow-up period of three months were reviewed retrospectively. Indications, surgical procedures, complications and outcomes of all surgeries were collected and analyzed.

MAIN OUTCOME MEASURES

Graft survival and visual acuity.

RESULTS

Data were available for 488 grafts in the study period, including 313 optical penetrating keratoplasty (PKP), 42 therapeutic/tectonic PKPs, 72 deep anterior lamellar keratoplasty, 58 Descemet's stripping automated endothelial keratoplasty and 3 Descemet's membrane endothelial keratoplasty. A total of 389 (79.7%) grafts survived, whereas 99 (20.3%) grafts failed. The projected 1-year, 3-year and 5-year cumulative survival rates for the entire study group were 85.8%, 74.9% and 71.1%, respectively. Corneal ectasia was the commonest surgical indication accounting for 48% of the cases. The best long-term survival rates were observed in the stromal dystrophy and corneal ectasia groups. The worst survival rates were noticed in the congenital corneal opacities group. Vision improved in in 57.5% of grafted eyes, remained the same in 39.8% and deteriorated in 2.7%. Postoperative complications occurred in 36% of the grafts with rejection being the most common, and its mere occurrence increased the risk of graft failure by 20-fold.

CONCLUSION

The outcome of grafting in a university-based hospital can be excellent in low-risk grafts and fair to low in high-risk grafts. Our results are relatively comparable to nationally and internationally reported outcomes.

Changing Trends in Penetrating Keratoplasty Indications between 2011 and 2018 - Histopathology of 2123 Corneal Buttons in a Single Center in Germany

Purpose: To analyse the changing trends in penetrating keratoplasty indications between January 2011 and December 2018, at the Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany. Patients and Methods: This is a retrospective review of 2123 corneal buttons of 1776 patients (1993 eyes, 56.0% males, age at the time of surgery 57.6 ± 18.7 years), who underwent penetrating keratoplasty (PKP) between January 2011 and December 2018. The classification was performed based on histological analysis and using the priority scheme of Brady et al., supplemented by a group of "failed endothelial keratoplasty grafts". Our groups were the following: pseudophakic or aphakic bullous keratopathy, regraft, failed endothelial keratoplasty graft, acute necrotizing and ulcerative keratitis, keratoconus, Fuchs' dystrophy, corneal dystrophy other than Fuchs', corneal scars and other diagnoses. Results: Between 2011 and 2018, keratoconus was the leading indication for PKP in 455 (21.5%) cases, followed by acute necrotizing and ulcerative keratitis in 384 (18.1%), regraft in 367 (17.3%), corneal scars in 350 (16.5%), pseudophakic or aphakic bullous keratopathy in 225 (10.6%), Fuchs' dystrophy in 194 (9.1%), other diagnoses in 64 (3.0%), corneal dystrophy other than Fuchs' in 52 (2.4%), and failed endothelial keratoplasty graft in 32 (1.5%) cases. Conclusions: With the introduction of posterior lamellar keratoplasty, keratoconus remains the leading PKP indication in our center with excimer laser-trephination on a routine basis. A trend towards increasing numbers can be observed regarding acute necrotizing and ulcerative keratitis patients and regrafts. However, the incidence of Fuchs' dystrophy decreased dramatically within PKP patients, with the introduction of posterior lamellar keratoplasty.

Effectiveness and safety of accelerated (9 mW/cm2) corneal collagen cross-linking for progressive keratoconus: a 24-month follow-up

OBJECTIVES

To examine the effectiveness and safety of accelerated corneal collagen cross-linking (CXL) for keratoconus over a 24-month period and to explore potential prognostic factors for post-treatment visual outcome and progression.

METHODS

A retrospective, non-comparative, interventional case series. All patients who underwent accelerated epithelium-off CXL, using 9 mW/cm² ultraviolet-A irradiation for 10 min, for progressive keratoconus in Sunderland Eye Infirmary, UK, between May 2014 and July 2016 were included. All patients completed 24 months' post-CXL follow-up. Significant post-CXL progression of keratoconus was defined as >1 D increase in Kmax from preoperative to 24-month visit.

RESULTS

Fifty-two eyes of 48 patients were included. At 24-month post-CXL, there was a significant improvement in corrected-distance visual acuity (CDVA; -0.05 LogMAR; p = 0.026), Kmax (-1.68 D; p < 0.001), K1 (-0.64 D; p = 0.002) and Kmean (-0.50 D; p = 0.009). The proportion of eyes with CDVA ≥ 0.3 LogMAR significantly improved from 43 (82.7%) eyes preoperatively to 50 (96.2%) eyes at 24 months (p = 0.026). Corneal haze (12, 23.1%) was the only postoperative complication and no adverse event was noted. Final CDVA was associated with lower CDVA (p = 0.002) and greater Kmax (p = 0.018) at baseline. Post-CXL progression of keratoconus was associated with greater preoperative Kmax (p = 0.12) and Kmean (p = 0.11), though statistical significances were not achieved.

CONCLUSIONS

Accelerated CXL (9 mW/cm²) serves as an effective and safe treatment for halting the progression of keratoconus and stabilising the vision over a 24-month period. Our observation suggests that accelerated CXL might be more effective in stabilising keratoconus of milder severity; however further larger studies are required to elucidate this finding.

Trends in corneal transplantation at the University Eye Hospital in Tübingen, Germany over the last 12 years: 2004 - 2015

Purpose

This study aimed to investigate the trends in the surgical methods and leading indications for corneal transplantations carried out over the last 12 years.

Methods

The data from the corneal graft waiting list and from all keratoplasties carried out between 2004 and 2015 at the University Eye Hospital in Tübingen were retrospectively analyzed.

Results

A total of 1,185 keratoplasties were performed between 2004 and 2015 at this hospital. The most common surgical indications for corneal transplantation were Fuchs’ endothelial corneal dystrophy (35.2%) and keratoconus (18.9%) with keratoconus being the leading cause during early years (from 2004 to 2009) and Fuch’s dystrophy being the leading cause from 2010 to 2015. Overall, the total count of performed keratoplasties increased, from 385 corneal transplantations during the first 6-year period to 800 corneal transplantations during the second 6-year period (P = 0.008, using Mann-Whitney test). The Descemet’s membrane endothelial keratoplasty has become the favored surgical method for endothelial disorders with the number of Descemet’s membrane endothelial keratoplasties increasing significantly from 2008 to 2015. This increasing trend was statistically significant (P < 0.001 using multivariate adaptive regression splines (MARS). A decreasing trend was also noted for the rate of penetrating keratoplasty since 2008 (P < 0.001 using MARS).

Conclusions

This research showed major changes in the preferred corneal transplantation techniques and leading indications for keratoplasty over the last 12 years. More importantly, it seems that the rapid development and implementation of endothelial keratoplasty, especially the Descemet’s membrane endothelial keratoplasty, has had a profound effect on and begun a new era in corneal transplantation.

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

OBJECTIVES

Study aims to evaluate the indications and surgical techniques for corneal transplantation and to report changes in trends for preferred keratoplasty surgical techniques.

METHODS

Clinical records of 815 consecutive corneal transplantations between January 1, 2004 and December 31, 2014 in Haydarpasa Numune Training and Research Hospital Eye Clinic were analyzed and classified into seven broad groups according to indications. Main outcome measures were change of leading indications and trends for surgical techniques.

RESULTS

Leading indications for keratoplasty were keratoconus (KCN) (27.7%), bullous keratopathy (BK) (23%), postinfectious corneal scars (13.5%), regrafts (13.1%), corneal dystrophies (12.1%), and noninfectious corneal scars (5.4%). Regrafts were the only indication with a significantly increasing trend (P<0.01). Since the introduction of lamellar keratoplasty (LK) techniques including deep anterior lamellar keratoplasty (DALK) and Descemet stripping automated endothelial keratoplasty (DSAEK), there was a significant increasing trend in number and percentage of both LK techniques (DALK; P=0.001 and P=0.007, and DSAEK; P<0.001 and P<0.001, respectively) and a significant corresponding decline in the percentage of penetrating keratoplasty (PK) (P<0.01). Similarly, DALK and DSAEK replaced PK as the preferred surgical technique for KCN and BK indications, (P=0.007 and P=0.01, respectively). Although PK was the most common surgical technique over the 11-year period (54.7%), both anterior and posterior LK techniques showed an emerging trend as the procedures of choice when indicated.

CONCLUSIONS

No major shift was observed in the clinical indications for corneal transplantation over the previous 11 years, except for regrafts. Lamellar keratoplasty techniques largely overtook the PK technique, but PK was still the overall preferred technique in the era when both LK techniques were used.

The Evolution of Corneal Transplantation

Background

The aim of this study was to investigate the evolution of surgical methods in and leading indications for corneal transplantation from 2005 to 2016.

Material/Methods

Data from the corneal graft waiting list and from all keratoplasties carried out between 2005 and 2016 at the University Eye Hospital Tübingen were retrospectively evaluated.

Results

A total of 1259 keratoplasties were performed between 2005 and 2016 at the University Eye Hospital Tübingen. The most common surgical indications for corneal transplantation were Fuchs endothelial corneal dystrophy (45.5%) and keratoconus (14.2%). The mean rate of corneal transplantations almost doubled from 71 keratoplasties per year in the first 6-year period to 139 keratoplasties per year in the second 6-year period (P=0.005). The number of penetrating keratoplasties remained similar. The number of Descemet membrane endothelial keratoplasties (DMEK) increased significantly from 2008 to 2016 (P<0.0001). One DMEK procedure was performed in 2008 (representing 1.4% of all transplantations), while 75 DMEK procedures were performed in 2016 (representing 60.5% of all transplantations) (P<0.0001). DMEK became the favored surgical method for endothelial disorders, exceeding penetrating keratoplasty in 2013.

Conclusions

Our study shows evolutionary changes in preferred corneal transplantation techniques and leading indications for keratoplasty from 2005 to 2016. Since its introduction a decade ago, DMEK is currently the golden standard in the management of corneal endothelial dysfunction.

Changing Indications in Penetrating Keratoplasty: A Systematic Review of 34 Years of Global Reporting

BACKGROUND

Penetrating keratoplasty (PK) ranks among the oldest and most common kinds of human tissue transplantation. Based on the hypothesis that reported indications for PK significantly vary between global regions and over time, the present systematic review aimed to provide a thorough overview of global PK indications as reported in peer-reviewed manuscripts.

METHODS

A literature search of PubMed and MEDLINE was conducted to retrieve articles published from January 1980 to May 2014. Indications for PK within 7 global regions were compared using a modified classification system for PK indications and analyzed via multivariate regression.

RESULTS

A total of 141 publications from 37 countries were included, recording 180 865 PK cases. Postcataract surgery edema was the predominant indication in North America (28.0%) and ranked second in Europe (20.6%), Australia (21.1%), the Middle East (13.6%), Asia (15.5%), and South America (18.6%). Keratoconus was the leading indication in Europe (24.2%), Australia (33.2%), the Middle East (32.8%), Africa (32.4%), and South America (22.8%). It ranked third in North America (14.2%). Keratitis was the primary indication in Asia (32.3%). Fuchs endothelial corneal dystrophy was the fourth most common indication in North America (12.9%) and Europe (10.2%) and fifth in South America (3.8%). Multivariate analysis supported these results and revealed individual regional changes over time.

CONCLUSIONS

Systematic analysis reveals characteristic chronological and regional differences in reported global PK indications. Leading reported indications for PK between 1980 and 2014 were keratoconus (Europe, Australia, the Middle East, Africa, and South America), pseudophakic bullous keratopathy/aphakic bullous keratopathy (North America), and keratitis (Asia).

Emergency corneal grafting in the UK: a 6-year analysis of the UK Transplant Registry

BACKGROUND

Corneal graft (CG) surgery is the most common and successful tissue transplant worldwide. A small and important group of patients are operated in emergency situations, typically to save a perforated eye. Our knowledge of the indications and outcomes of emergency corneal graft (eCG) is limited.

METHODS

Retrospective, multifactorial analysis of all CGs registered by the UK Transplant Service from April 1999 to March 2005.

RESULTS

A total of 12 976 CGs were performed. 1330 (11.4%) were eCGs including 433 regrafts. Actual perforation occurred in 876 (65.9%) patients. 420 (31.5%) grafts were for tectonic purposes alone and 217 (16.3%) were also grafted for visual rehabilitation. The main diagnostic categories were infection (39.4%), non-infectious ulcerative keratitis (32.2%) and other causes (ectasias, previous ocular surgery, injury, dystrophies and opacification). Graft survival of first eCG at 1, 2 and 5 years was 78%, 66% and 47%, respectively. Best-corrected visual acuity of surviving grafts at 1 year was: 6/12 or better in 29.9%, 6/18 to 6/60 in 38.4%, counting finger to LP in 30.6% and NPL in 1%, with worsening of vision in only 8.7% of the patients.

CONCLUSION

This study which is the largest of its kind shows that despite the seriousness of the critical corneal pathology and the surgical challenges that it poses, the outcomes of eCG are favourable with most patients keeping their eyesight and avoiding immediate rejection. These clinical outcomes show the value of eye banking facilities that are developed to support corneal tissue supply for eCG.

Changes in Technique and Indications for Keratoplasty in Poland, 1989 to 2014: An Analysis of Corneal Transplantations Performed at Saint Barbara Hospital, Trauma Center, Sosnowiec, Poland

BACKGROUND

The purpose of this work was to study the evolving trends in techniques and indications for corneal transplantation in Poland.

METHODS

This retrospective, descriptive analysis of corneal transplantations was performed at the Ophthalmology Department of Saint Barbara Hospital, Trauma Center, Sosnowiec, Poland, between 1988 and 2014. Structure of indications and surgery type rates over 26 years were tabulated by means of 5-year intervals.

RESULTS

Between 1989 and 2014, 1762 corneal transplantations were performed, including 1375 (78%) cases of penetrating keratoplasty, 137 (8%) lamellar keratoplasty, 112 (6%) patch grafts, and 138 (8%) keratolimbal allografts. The major indications and their respective overall percentage were corneal leucoma (24%), pseudophakic/aphakic bullous keratopathy (22%), Fuchs dystrophy (13%), keratoconus (13%), re-graft (11%), keratitis (9%), and limbal stem cell deficiency (8%), with changes in relative frequency of the leading indications over the following time intervals. The number of corneal transplantations gradually increased during the years reviewed. The rates of lamellar, keratolimbal, and patch grafts have grown dynamically since 2010, reaching 20%, 17%, and 12%, respectively, of procedures performed during 2010 to 2014.

CONCLUSIONS

Over the past quarter of a century, there has been evolution in corneal transplantation service, from the first penetrating keratoplasty to the wide spectrum of procedures, including femtosecond laser-assisted keratoplasty. Although, since 2010, the rates of lamellar and keratolimbal allografts have grown rapidly, penetrating keratoplasty has remained the leading technique.

Current techniques of lamellar keratoplasty for keratoconus

In recent years, there has been a considerable interest regarding the concept of lamellar keratoplasty (LK), which contributed in spreading the use of this procedure in the treatment of keratoconus. This is a new frontier in corneal surgery that minimizes trauma on the recipient patient since it works on a "closed bulb". The LK surgery, in fact, aims to selectively replace diseased corneal stroma, leaving the healthy endothelium. The main advantage of LK is to avoid major causes of failure of penetrating keratoplasty as immunological rejection, and the late mismatch in the transplanted cornea, thus increasing the life of transplantation. In the last decade, several techniques of LK have been proposed, depending on how the anterior portion of the recipient cornea is removed. This article, through a literary research reviews the various emerging techniques of anterior lamellar surgery for the management of keratoconus, analyzing their indications, visual outcomes, and rate of complications.

Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus: a national registry study

PURPOSE

Keratoconus is a progressive disorder and one of the primary indications for corneal transplantation. Anterior lamellar keratoplasty offers several advantages over other techniques, including endothelial preservation and longer graft survival. In this study, we examined the recent trend of using lamellar techniques for keratoconus at a national level.

METHODS

Data were obtained from the Dutch national organ transplant database regarding corneal transplants for keratoconus performed in 2005 through 2014. Baseline characteristics for patients undergoing various techniques were obtained, and temporal trends were analysed.

RESULTS

A total of 1041 operations were performed, including 736 penetrating keratoplasties (PKPs) and 297 anterior lamellar keratoplasties (ALKs). The mean age of the total surgical group was 37.4 ± 13.4 years, and 68% of patients were male (p = 0.0001). Preoperative patient characteristics were reported in all 1041 cases. The relative proportion of ALKs increased from 2005 (19% of cases) to 2010 (39% of cases) and remained approximately 30-40% thereafter. Descemet baring or deep anterior lamellar keratoplasty (DALK) was increasingly applied and was the predominant anterior lamellar technique performed from 2009 onwards.

CONCLUSIONS

The number of corneal transplantations performed annually for keratoconus decreased during the past 10 years. Lamellar techniques were increasingly performed, accounting for approximately 35% of keratoplasties in 2010 and thereafter. Among ALK techniques, maximal depth DALK is the most prevalent keratoplasty performed for keratoconus in most recent years. Penetrating keratoplasty (PKP) is still common, with a stable frequency from 2010 onwards.

Corneal collagen cross-linking followed by phacoemulsification with IOL implantation for progressive keratoconus associated with high myopia and cataract

PURPOSE

To evaluate the visual and topographic outcomes of a two-stage approach treatment for progressive keratoconus (KC) associated with high myopia and cataract.

METHODS

Two patients, a 50-year-old man and a 54-year-old woman with high myopia (spherical equivalent greater than -10D), cataract, and progressive KC with poor spectacle-corrected vision and contact lens intolerance underwent a 2-stage approach treatment: first corneal collagen cross-linking (CXL) followed after at least 6 months by phacoemulsification with intraocular lens (IOL) implantation in both eyes.

RESULTS

In both patients after a mean follow-up of 3.5 years (from 2 to 4) uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and corneal topography pattern improved in both eyes, and the patients were satisfied with the visual improvement and happy with tolerable glasses.

CONCLUSION

This 2-stage approach reported no complications and was effective in improving visual acuity and corneal patterns in patients with high myopia, cataract, and progressive KC.

Mechanisms for acute corneal hydrops and perforation

Acute corneal hydrops (ACH) and perforation in corneal thinning diseases are the consequences of exposure to distending intraocular pressure (IOP) forces that are in excess of corneal resistance to them. Apart from thinning, resistance to these forces may be reduced by disease-related tissue changes, such as corneal scarring, which could lower resistance to IOP. Eye rubbing trauma has sometimes been found to be associated with ACH and perforation. This association is not surprising given that the combination of rubbing-related mechanical tissue trauma and the associated increased distending stress of higher IOP seem likely to increase the risk of complications. Many cases of ACH and perforation are described as spontaneous, but this classification may be the consequence of not considering the multiple potential mechanisms for IOP elevation such as coughing, sneezing, nose blowing, and sneeze suppression in addition to those related to eye rubbing/wiping/massaging/touching as well as changes in body orientation, strenuous exercise, and wearing swimming goggles for example. Classification of ACH or perforation as spontaneous may lead patients to assume that nothing can be done to avoid these complications. Patients with corneal thinning diseases who are counseled regarding the potential precipitating mechanisms for IOP elevation will have the opportunity of reducing exposure to them and the risk of the associated complications. In addition, when ACH or perforation occur, faster resolution of edema and wound healing may depend on reducing potentially exacerbating exposures to mechanisms for IOP elevation.

Effect of postmortem interval on the graft endothelium during preservation and after transplantation for keratoconus

PURPOSE

To investigate the effect of postmortem intervals and prognostic factors on endothelial cell density (ECD) of human donor corneas during preservation and at 1 and 3 years after transplantation in patients transplanted for keratoconus.

METHODS

Two different studies were performed: (1) with 733 donor corneas selected for the preservation study and (2) 64 patients with keratoconus selected retrospectively from 2 hospital clinics. The corneas were evaluated on the basis of the ECD during preservation, study A, and at 1 and 3 years after transplantation, study B. The effect of ≥ 10 hours of postmortem interval on the percentage of corneal endothelial cell loss (ECL) was determined.

RESULTS

The multiple regression showed no statistical significance (P = 0.827) of postmortem interval on ECL during preservation. However, for patients with keratoconus, the postmortem interval was statistically significant at both 1 year (P < 0.0001) and 3 years after transplantation (P < 0.0001).

CONCLUSIONS

The postmortem interval has no influence on the ECD during preservation. However, it has a statistically significant effect on the ECL after transplantation for patients transplanted for keratoconus, and therefore, it becomes eligible to be one of the potential factors affecting the ECD apart from surgical trauma.

Outcome of corneal transplantation in a private institution in Saudi Arabia

Background

The aim of this work was to describe the indications, complications, and outcomes of penetrating keratoplasty (PKP) in Saudi Arabia.

Methods

In a retrospective, noncomparative interventional case series, the medical records of patients who underwent PKP from January 2000 to December 2008 and had a minimum follow-up of 6 months were reviewed. All corneas were obtained from eye banks in the US. Indications, complications, and outcomes of surgery were recorded. This study was approved by the institutional review board.

Results

Eighty-five consecutive eyes were included in this study. There were 52 (61.2%) males and 33 (38.8%) females. The median age was 35.0 years (range 3–85 years), and the median follow-up period was 24 months (range 6–108 months). The indications for PKP were keratoconus, bullous keratopathy, corneal scars, corneal dystrophy, and corneal regraft. The overall graft survival time was 88.9 months ± 4.9 months (mean ± standard error of mean, 95% confidence interval [CI] 79.4 months –98.4 months) while the 3-year and 5-year cumulative survival rates were 90.7% and 84.3%, respectively. Surgical indication (P = 0.038), immune rejection (P < 0.001), preoperative corneal vascularization (P = 0.022), and perioperative high intraocular pressure (P = 0.032) were associated significantly with corneal graft failure in univariate analysis. Multivariate analysis reduced these significant associations to rejection (P < 0.001) and vascularization (P = 0.009). Relative risk for failure in rejected cornea was 16.22 (95% CI 4.99–52.69) and in vascularized cornea was 3.89 (95% CI 1.36–11.09). At last visit following PKP, 34 (40%) eyes had best spectacle-corrected visual acuity of 20/40 or better, and 51 (60.0%) eyes had 20/80 or better. Best spectacle-corrected visual acuity was worse than 20/400 in 15 (17.6%) eyes.

Conclusion

The overall corneal graft survival in a private setting in Saudi Arabia can be excellent. Thorough preoperative evaluation and comprehensive postoperative management are crucial for successful corneal transplantation. A larger multicenter study is recommended to portray the outcome of private corneal transplantation in Saudi Arabia in general.

Long-term changes in corneal endothelial cell density after repeat penetrating keratoplasty in eyes with endothelial decompensation

PURPOSE

To compare the longitudinal changes in corneal endothelial cell density (ECD) and the incidence of postoperative complications between eyes with endothelial decompensation after repeat penetrating keratoplasty (RPK) and those after primary penetrating keratoplasty (PPK).

METHODS

Fifty-seven eyes with endothelial decompensation scheduled for RPK (RPK group) and 57 eyes with endothelial decompensation scheduled for PPK (PPK group) were enrolled. Corneal ECD was evaluated using a specular microscope at 1, 3, 6, 9, and 12 months, and every 6 months until 60 months postoperatively. Visual acuity (VA) and incidence of graft failure, graft rejection, or marked increase in intraocular pressure were examined.

RESULTS

Corneal ECD decreased gradually and percentage of cell loss at 60 months was approximately 73% in both groups; these did not differ significantly between groups throughout the follow-up (P ≥ 0.2209). The incidence of graft failure (52.6% in the RPK group and 36.8% in the PPK group), immune rejection, and marked increase in intraocular pressure did not differ significantly between groups (P ≥ 0.0898), although corrected VA was worse in the RPK group. The most common cause of graft failure in both groups was late endothelial failure. The outcomes were not significantly different between eyes that underwent a first RPK and those that underwent a second or subsequent RPK.

CONCLUSIONS

Corneal endothelial cell loss and complications are comparable between eyes with endothelial decompensation after RPK and those after PPK, although VA is worse in eyes after RPK. The outcomes after a first RPK did not differ from those after multiple RPKs.

Changing indications for penetrating keratoplasty in Homburg/Saar from 2001 to 2010--histopathology of 1,200 corneal buttons

BACKGROUND

To evaluate the trends in indications for penetrating keratoplasty (PKP) in Homburg/Saar between 2001 and 2010.

METHODS

Retrospective review of 1,200 corneal buttons which underwent PKP that were performed between 2001 and 2010 at the Department of Ophthalmology of Saarland University Hospital, Germany. Indications were classified into eight different groups following histological analysis: keratoconus, Fuchs' dystrophy, bullous keratopathy, corneal scars, keratitis, regraft, corneal dystrophy other than Fuchs' dystrophy, and other diagnoses. Two different time periods (between 2001-2005 and between 2006-2010) were analyzed.

RESULTS

Keratoconus (25.5 %) was the most common indication for PKP in our study, followed by Fuchs' dystrophy (21.2 %), bullous keratopathy (14.6 %), corneal scars (14.4 %), keratitis (13.0 %), regraft (7.0 %), non-Fuchs' dystrophies (2.1 %), and other diagnoses (2.3 %). Comparing the two different time periods, a trend of significantly increasing frequency of keratoconus and Fuchs' dystrophy, and a decreasing frequency of corneal scars, were found as indications for PKP in our study.

CONCLUSIONS

Keratoconus was the leading indication for PKP in our series, and had a significantly increasing trend from 2001-2005 to 2006-2010. The percentage of patients with Fuchs' dystrophy increased, and became the second most common indication for PKP, while the number of PKPs for corneal scars decreased during the last 5 years in our institution.

Health status and patient satisfaction after corneal graft: results from the corneal transplant epidemiological study

Purpose. To evaluate effects of corneal transplantation on the health-related quality of life and patients' satisfaction. Methods. Patients scheduled for elective penetrating or anterior lamellar keratoplasty completed by telephone interview the SF-12 Health Survey, before and one year after surgery, and a 6-item questionnaire on the satisfaction for graft outcomes. Results. The two questionnaires were answered by 1,223 patients. Transplantation did not influence the PCS-12 in males (ES = -0.01) and had a negative effect in females (ES = -0.18). Both sexes improved their MCS-12 (ES = 0.18 and 0.23, resp.). The majority of patients (83.1%) were satisfied by the outcome of the graft. Conclusions. This is the first report on the use of the SF-12 and one of the few that assess quality of life in patients after corneal transplantation. We showed that grafting improves patients' health-related quality of life results of patients, influencing mental health (i.e., psychological attitude, social interaction, and emotions) with minor effects on physical health (limitation, pain, and vitality).

Longterm follow-up of penetrating keratoplasty for keratoconus

PURPOSE

This study aims to describe the current visual and refractive status of patients who underwent penetrating keratoplasty (PK) for keratoconus > 20 years ago and to report on the current status of their grafts.

METHODS

A total of 138 eyes in 103 patients were grafted for keratoconus between August 1968 and December 1985. Patients who had not undergone retransplantation were invited to attend a clinical examination. Forty-eight patients (with 61 grafts) accepted the invitation and were examined.

RESULTS

The average length of time since PK was 26.9 years (standard deviation [SD] 4.2 years, range 20.8-38.0 years, n = 61). The average graft age at examination was 82.1 years (SD 19.9 years, range 41-115 years). A total of 80% (49 of 61 grafts) of the examined eyes had a clear graft and 46% (28 of 61 eyes) had best spectacle-corrected visual acuity (BSCVA) > or = 0.5. The mean endothelial cell density per mm(2) was 894 (SD 4.6, range 470-1775). The mean central corneal thickness of the clear grafts was 0.565 mm (SD 0.048 mm).

CONCLUSIONS

Penetrating keratoplasty for keratoconus has a good longterm prognosis; half of the eyes examined in this study had BSCVA > or = 0.5 at > 20 years after surgery.

Fuchs' corneal dystrophy

Fuchs' corneal dystrophy (FCD) is a progressive, hereditary disease of the cornea first described a century ago by the Austrian ophthalmologist Ernst Fuchs. Patients often present in the fifth to sixth decade of life with blurry morning vision that increases in duration as the disease progresses. Primarily a condition of the posterior cornea, characteristic features include the formation of focal excrescences of Descemet membrane termed 'guttae', loss of endothelial cell density and end-stage disease manifested by corneal edema and the formation of epithelial bullae. Recent advances in our understanding of the genetic and pathophysiological mechanisms of the disease, as well as the application of new imaging modalities and less invasive surgical procedures, present new opportunities for improved outcomes among patients with FCD.

Corneal graft survival after therapeutic keratoplasty for Acanthamoeba keratitis

PURPOSE

To describe corneal graft survival and visual outcome after therapeutic penetrating keratoplasty in patients with Acanthamoeba keratitis (AK) that is unresponsive to clinical treatment.

METHODS

Retrospective study. Thirty-two patients with AK who underwent therapeutic penetrating keratoplasty (tPK) from August 1996 to August 2005 were included. Data relating to clinical features, visual acuity, surgical technique, graft survival and complications were collected. Graft survival was evaluated by the Kaplan-Meier method and comparisons were performed using the Log-rank test.

RESULTS

Most patients (62.5%) were female. Mean age [+/- standard deviation (SD)] was 35 (+/- 13) years (range 15-68 years). All patients were contact lens wearers. Eighteen patients (56%) presented paralytic mydriasis and glaucoma during the treatment. Thirteen patients (40%) developed glaucoma after surgery; eight of them (61%) required a second PK because of graft failure. Of the 32 keratoplasty eyes, 56.2% presented graft failure at any follow-up point. Forty-five per cent of graft failures occurred before the 12 month follow-up, so 55% remained clear in the first year after surgery. Twelve patients underwent a second PK; seven of them failed and 45% were clear at 1 year. Two patients presented graft recurrence of amoebic infection. There was no significant difference in graft survival when eyes with or without mydriasis were compared (P = 0.40). Eyes with glaucoma presented a significantly shorter graft survival (P = 0.01).

CONCLUSION

Penetrating keratoplasty is a treatment option for eyes that are unresponsive to clinical treatment infections. However, graft survival is poor; postoperative glaucoma is frequent and is associated with shorter graft survival.