Changing indications for penetrating keratoplasty: histopathology of 1,250 corneal buttons

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.

Descemet Stripping without Transplantation in Fuchs Endothelial Corneal Dystrophy

Traditionally, corneal endothelium is considered post-mitotic, which means that spontaneous regeneration after loss of endothelial cells (e.g., in the context of Fuchs endothelial corneal dystrophy) is not expected. Nevertheless, it has been observed in several cases that an edematous cornea can clear after removal of a smaller area of Descemet's membrane. The posterior aspect of this area becomes covered again by corneal endothelial cells. This has resulted in a new surgical approach that does not involve a posterior lamellar graft: "Descemet stripping only". At the same time, data from in vitro experiments suggest that Rho kinase inhibitors (ROCK inhibitors) are pharmacological agents that promote proliferation and migration of corneal endothelium, and thus have a positive influence on healing.

Descemet membrane endothelial keratoplasty in a patient with iris-fixated intraocular lens and prior radial keratotomy: a case report

Background

Anterior segment surgeries such as cataract surgery, intraocular lens (IOL) repositioning, and radial keratotomy (RK) may hasten endothelial dysfunction, particularly in the context of pre-existing Fuchs dystrophy, necessitating future corneal transplantation.

Case presentation

A 68-year-old woman with a history of RK with associated irregular astigmatism in both eyes and iris-fixated intraocular lens (IF-IOL) in the left eye presented with six months of decreased vision in the left eye. She was found to have Fuchs dystrophy and underwent DMEK surgery. She had an uncomplicated postoperative course, with uncorrected visual acuity improving to 20/20 three months after surgery.

Conclusion

To our knowledge, this is the first reported case of a highly successful DMEK surgery in a patient with prior RK and IF-IOL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02103-1.

Changing trends in penetrating keratoplasty indications at a tertiary eye care center in Budapest, Hungary between 2006 and 2017

AIM

To analyze the changing trends in penetrating keratoplasty (PKP) indications.

METHODS

This retrospective study included all patients with PKP between 2006 and 2017. Patients were classified using histological diagnoses. Our groups were as the following: pseudophakic or aphakic bullous keratopathy, regraft, acute necrotizing and ulcerative keratitis, keratoconus, Fuchs' dystrophy, corneal dystrophy other than Fuchs', corneal scar, other diagnoses and failed endothelial keratoplasty graft. Additionally, two different time-periods (2006-2012 and 2013-2017) were analysed.

RESULTS

Totally 1721 histological analyses of 1214 patients were available for review. The diagnoses were pseudophakic or aphakic bullous keratopathy in 487 (28.3%), regraft in 443 (25.7%), acute necrotizing and ulcerative keratitis in 313 (18.2%), corneal scar in 153 (8.9%), keratoconus in 140 (8.1%). Fuchs' dystrophy in 61 (3.5%), corneal dystrophy other than Fuchs' in 46 (2.7%), other diagnoses in 44 (2.6%) and failed endothelial keratoplasty graft in 34 (2.0%) cases. From the first to the second analysed time-period, incidence of acute necrotizing and ulcerative keratitis, corneal scar, Fuchs' dystrophy increased (P≤0.032 for all) and incidence of keratoconus significantly decreased (P=0.015).

CONCLUSION

Pseudophakic or aphakic bullous keratopathy is the leading indication for PKP, followed by regraft and acute necrotizing and ulcerative keratitis.

Metabolomic Signature Discriminates Normal Human Cornea from Keratoconus-A Pilot GC/MS Study

The molecular etiology of keratoconus (KC), a pathological condition of the human cornea, remains unclear. The aim of this work was to perform profiling of metabolites and identification of features discriminating this pathology from the normal cornea. The combination of gas chromatography and mass spectrometry (GC/MS) techniques has been applied for profiling and identification of metabolites in corneal buttons from 6 healthy controls and 7 KC patients. An untargeted GC/MS-based approach allowed the detection of 377 compounds, including 46 identified unique metabolites, whose levels enabled the separation of compared groups of samples in unsupervised hierarchical cluster analysis. There were 13 identified metabolites whose levels differentiated between groups of samples. Downregulation of several carboxylic acids, fatty acids, and steroids was observed in KC when compared to the normal cornea. Metabolic pathways associated with compounds that discriminated both groups were involved in energy production, lipid metabolism, and amino acid metabolism. An observed signature may reflect cellular processes involved in the development of KC pathology, including oxidative stress and inflammation.

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.

Repeat Keratoplasty for Failed Therapeutic Keratoplasty for Microbial Keratitis: An Analysis of Characteristics and Risk Factors

Purpose

To report the ratio of repeat-to-initial keratoplasty among patients who had underwent therapeutic keratoplasty for microbial keratitis in Southern China and to investigate the characteristics and risk factors of repeat keratoplasty.

Methods

A retrospective and inclusive review of the clinical records of patients who had received therapeutic keratoplasty for microbial keratitis, at Zhongshan Ophthalmic Center during December 2012 to January 2018, was performed. Patients who suffered coexistent endophthalmitis or underwent keratoplasty combined with other surgeries were excluded. Data on clinical characteristics of all eligible patients were collected.

Results

A total of 447 patients were identified. Their mean age was 48.7 ± 15.5 years, and 290 (64.9%) were male. Out of the 447 patients, 18 (4.0%) received repeat keratoplasty. Their mean age was 45.9 ± 11.3 years, and 14 (77.8%) were male. The most common indication of repeat keratoplasty (12/18) was refractory infectious keratitis. Most of the patients (15/18, 83.3%) received the second keratoplasty within 12 months after the initial keratoplasty. Factors, including age, gender, initial causative organism, presence of initial corneal perforation, ocular comorbidities, and surgical procedures were not found statistically significantly different between patients who received and not received repeat keratoplasty.

Conclusion

The ratio of repeat-to-initial keratoplasty for therapeutic keratoplasty is low, compared to a failure rate of the initial grafts of over 50% reported in previous studies. The low ratio and the most common indication of repeat keratoplasty, refractory infectious keratitis, reflect caution for performing regrafts in such patients.

Descemet's Membrane Endothelial Keratoplasty with Split Corneal Grafts: The Influence of Tamponade Material and Endothelial Storage Time

Purpose: The aim of this study was to describe the clinical outcome of Descemet's membrane endothelial keratoplasty (DMEK) performed with split corneal grafts and to evaluate the influence of tamponade material and endothelial storage time on DMEK success. Material and Method: The records of 43 patients who underwent DMEK surgery with a split corneal graft were reviewed. Diagnosis of the patients, preoperative and postoperative best-corrected visual acuity (BCVA), corneal and endothelial storage time, tamponade material, complications, and success rates were specifically tabulated. Results: The most common indication for DMEK was pseudophakic bullous keratopathy (n = 25, 58.2%). Re-bubbling was needed in 10 cases (23.2%), and a re-DMEK was scheduled in 2 cases and penetrating keratoplasty in 4 cases (9.3%). BCVA improved significantly postoperatively (p < .001). There was an insignificant trend towards a lower re-bubbling rate and better long-term anatomic outcome in favor of 20% SF6 group compared to air tamponade (p = .18 and p = .25). There was no significant difference between the early endothelial transplant (<24 h) and delayed endothelial transplant (3 to 14 days) groups for anatomic success, corneal thickness or BCVA (p = .94, p = .13 and p = .35). Conclusion: The success rate of DMEK was satisfactory with split corneal grafts. There was no adverse influence of delayed endothelial transplantation on clinical outcome. The success rate of 20% SF6 tamponade was slightly better than room air.

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.

Trends in Corneal Transplantation from 2001 to 2016 in Germany: A Report of the DOG-Section Cornea and its Keratoplasty Registry

PURPOSE

The purpose of this retrospective panel study was to provide an overview of absolute numbers and of trends in the types of and indications for corneal transplantation in Germany from 2001 to 2016.

METHODS

A questionnaire about absolute numbers, types of transplantation, and indications was sent to 111 ophthalmologic departments in Germany, out of which 94 (85%) provided their data.

RESULTS

Since the year 2001, the number of corneal transplantations has increased by 1.5-fold, from 4730 penetrating keratoplasties (PKPs) in 2001 to 7325 penetrating and lamellar keratoplasties in 2016. The shift from penetrating to lamellar procedures began in 2006. In 2014, lamellar procedures (231 [4%] anterior and 2883 [49%] posterior lamellar keratoplasties) surpassed PKPs (2721, 47%) for the first time. Main indications for keratoplasty in Germany (2016) are Fuchs endothelial corneal dystrophy (46%), pseudophakic corneal decompensation (bullous keratopathy, 13%), repeated keratoplasty after graft failure (11%), keratoconus (8%), and corneal scarring (6%; others: 16%). The number of Descemet membrane endothelial keratoplasties (DMEKs) was 12 times higher (3850, 53%) than Descemet stripping automated endothelial keratoplasties (DSAEKs, 319, 4.4%) in 2016. The proportion of deep anterior lamellar keratoplasties (DALKs) never exceeded 6% (269 in 2011).

CONCLUSIONS

The number of keratoplasties in Germany has increased from 2001 to 2016. Since 2014, posterior lamellar keratoplasties have surpassed PKPs. There was a constant increase of DMEKs, with a 12-fold higher number compared to DSAEKs in 2016. The shorter recovery time after DMEK seems to contribute to the trend toward earlier operative intervention in corneal endothelial diseases.

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).

Microbial Keratitis After Penetrating Keratoplasty

PURPOSE

To report the incidence, microbiological profile, graft survival, and determining factors of microbial keratitis after penetrating keratoplasty (PK).

DESIGN

Observational case series.

METHODS

The study involved 51 patients (52 eyes) who were treated at a single tertiary referral center during a 10-year period. Retrospective chart review included medical records of all patients diagnosed with microbial keratitis after penetrating keratoplasty at the National Taiwan University Hospital between January 2000 and December 2009. The main outcome measures were incidence of graft infection, microbial profile, and graft survival status.

RESULTS

There were 871 PKs performed and 67 episodes in 52 eyes of culture-positive microbial keratitis during the study period. There were 32 infectious episodes (47.8%) in the first year post-PK and 35 episodes (52.2%) after the first year post-PK. Forty-four gram-positive bacterial isolates (57.9%), 17 gram-negative bacterial isolates (22.4%), and 15 fungal isolates (19.7%) were found. Twenty-three (34.3%) grafts remained clear after the infection episode with a mean follow-up of 1127 days (range, 25-3962 days). There was no difference in graft survival rate regarding the original indication of PK or offending pathogen. Suture-related infection was associated with decreased risk of graft failure (P = .02), while the factor associated with increased risk of graft failure was usage of antiglaucoma agents (P = .01).

CONCLUSION

Infectious keratitis after penetrating keratoplasty leads to a high graft failure rate. Such complications can occur before or after the first year post-PK.

Trends in Indications and Techniques of Corneal Transplantation in Iran from 2006 to 2013; an 8-year Review

Purpose:

To report changing trends in indications and techniques of corneal transplantation in Iran.

Methods:

We reviewed eye bank records of 47,129 patients who had undergone corneal transplantation between 2006 and 2013 at different eye centers throughout Iran.

Results:

The most common indication for corneal transplantation was keratoconus (KCN, n = 21,350 eyes, 45.3%), followed by bullous keratopathy (BK, n = 8,566 eyes, 18.2%), corneal opacity and scar (COS, n = 7,158 eyes, 15.2%), graft failure (n = 3,252 eyes, 6.9%), corneal dystrophies (n = 2,553 eyes, 5.4%), and infectious keratitis (n = 2,238 eyes, 4.7%). Over the study period, there was a significant increase in the frequency of BK (P = 0.001) and graft failure (P = 0.025), and a significant decrease in the relative frequency of COS (P = 0.012). The prevalence of KCN (P = 0.172), infectious keratitis (P = 0.107), and corneal dystrophies (P = 0.836) remained unchanged. The most common technique of corneal transplantation was penetrating keratoplasty (PKP, n = 33,476 eyes, 71.0%), followed by deep anterior lamellar keratoplasty (DALK, n = 8,363 eyes, 17.7%), Descemet's stripping automated endothelial keratoplasty (DSAEK, n = 3,516 eyes, 7.5%), tectonic (n = 1752, 3.7%), and keratolimbal allograft (KLAL, n = 19 eyes, 0.1%). Regarding the shift in surgical techniques, a significant increase was observed in DSAEK (P < 0.001), whereas PKP was significantly decreased (P = 0.005) over the 8-year period. No significant change was seen in the rates of DALK (P = 0.354), tectonic graft (P > 0.999) and KLAL (P = 0.151).

Conclusion:

KCN was the most common indication and PKP was the most prevalent technique used for corneal transplantation. Significant changes in surgical techniques were observed over the past 8 years; DSAEK demonstrated an increasing trend while PKP showed a decrease.

Prevention and treatment of corneal graft rejection: current practice patterns of the Cornea Society (2011)

PURPOSE

To analyze current practice patterns in the prevention and treatment of corneal graft rejection for both penetrating keratoplasty (PK) and endothelial keratoplasty (EK) and to compare these patterns with previously reported practices.

METHODS

In 2011, an electronic survey was sent to 670 members of the Cornea Society worldwide addressing the routine postoperative management of corneal transplants at different time points, treatment of various manifestations of corneal graft rejection, and preferred surgical techniques.

RESULTS

A total of 204 of 670 surveys (30%) were returned and evaluated. All respondents used topical corticosteroids for routine postoperative management and treatment of endothelial graft rejection. Prednisolone was the topical steroid of choice in all clinical scenarios, similar to previous surveys from 1989 to 2004. Use of subconjunctival and systemic steroids increased for many scenarios of probable and definite graft rejection. Routine use of prednisolone decreased by approximately 10% from previous surveys, whereas difluprednate was used in 13% of high-risk eyes during the first 6 months. Dexamethasone, fluorometholone, and loteprednol use remained stable. Adjunctive topical cyclosporine use increased significantly for PK and EK. EK was the preferred technique for endothelial dysfunction, whereas PK and deep anterior lamellar keratoplasty were both used for keratoconus and anterior scars. Most respondents (75%) felt that graft rejection occurs more frequently after PK than after EK.

CONCLUSIONS

Prednisolone remains the treatment of choice for management and treatment of graft rejection; however, since the introduction of difluprednate, its use has declined slightly since the introduction of difluprednate. Despite perceived differences in rejection rates, there were no differences in prophylactic steroid treatment for PK and EK.

Indications and techniques employed for keratoplasty in the Eastern province of Saudi Arabia: 6 years of experience

BACKGROUND AND OBJECTIVES

Keratoplasty services in Saudi Arabia have progressed steadily in the past few decades. We sought to identify the leading indications and types of keratoplasty performed in the Eastern Province of Saudi Arabia over a six-year period and to compare these indications with published data.

DESIGN AND SETTING

This was a retrospective descriptive analysis of the records of patients who underwent keratoplasty at four ophthalmology centers in the Eastern Province between 2008 and 2013.

PATIENTS AND METHODS

All keratoplasty procedures were included in the analysis. The primary surgical indication and type of surgery were identified for each case.

RESULTS

Keratoplasties included 570 penetrating keratoplasty, 217 deep lamellar keratoplasty, 80 triple procedures, 24 descemet stripping automated endothelial keratoplasty and 12 Boston keratoprosthesis implantations. The mean age of all patients was 28.8 years (range 14-72 years), and 58.9% of the patient were males. The lead.ing indication for keratoplasty was keratoconus 53.10%, bullous keratopathy 13.80%, corneal scarring 10.7%, regrafts 9.1%, and stromal dystrophies 4.9%.

CONCLUSIONS

In this study, the leading indications for keratoplasty were keratoconus, bullous keratopathy, corneal scarring, regrafts and stromal dystrophies. A significant increasing trend for descemet's stripping automated endothelial keratoplasty surgeries was observed in spite of the number of cases.

Causes that influence the detachment rate after Descemet membrane endothelial keratoplasty

PURPOSE

To investigate Descemet graft (DG) detachment rate after Descemet membrane endothelial keratoplasty (DMEK) in relation to DG position.

METHODS

A total of 175 consecutive pseudophakic eyes that underwent DMEK (175 eyes for Fuchs endothelial dystrophy) from September 2009 through February 2014 at the Tübingen Eye Hospital DG position were studied retrospectively by surgical video at the end of an operation. A group of 45 eyes showed a decentration of the DG with a stromal gap of ≥1.5 mm over at least 3 clock hours between the descematorhexis edge and the DG. DG detachment was documented at a mean follow-up of 13.9 ± 3.7 months after surgery. DG detachment was defined as a detachment of 20 % or more of the DG surface area. Various donor characteristics and patient characteristics were analyzed.

RESULTS

The best spectacle-corrected visual acuity (BCVA) in the group of eyes with central well-positioned DG differed significantly from those of eyes with decentered DG. The preoperative BCVA in the central well-positioned DG group was 0.63 ± 0.40 logMAR, and in the decentered DG group 0.91 ± 0.51 logMAR (P < 0.001). The postoperative BCVA in the group of eyes with central well-positioned DG was 0.12 ± 0.11 logMAR, and in the group with decentered DG 0.23 ± 0.29 logMAR (P < 0.001). Endothelial cell density and patient characteristics such as age, gender, and intraocular pressure did not differ significantly between the two groups. The group of eyes with central well-positioned DG showed DG detachment in 12 %; the group with decentered DG findings had DG detachment in 87 % (P < 0.001) at the 12 month follow up.

CONCLUSION

The present findings demonstrate the importance of central well-positioned DG and the relation of disease severity. Central well-positioned DG may reduce the incidence of DG detachment. Overlapping of the donor DG and the host Descemet membrane seems to be responsible for DG detachment. One possible way to enhance graft adhesion could be a larger descematorhexis, which avoids an overlapping. The second possible way could be not waiting too long for surgery to reduce disease severity.

Evaluation of broadband spectral transmission characteristics of fresh and gamma-irradiated corneal tissues

PURPOSE

The aim of this study was to evaluate the clarity of gamma-irradiated sterile corneal donor lenticules.

METHODS

Broadband UV, visible, and near-infrared (200-850 nm) light transmission was measured through gamma-irradiated, sterile partial-thickness, and full-thickness donor lenticules and fresh corneal tissues and compared with standard acrylic intraocular lens (IOL) implants using a conventional spectrophotometer technique.

RESULTS

All tissues had high light transmission (≥ 90%) in the visible and near-infrared regions and very low (<2%) transmission below 290 nm. Differences in light transmission between irradiated and fresh cornea types were observed between 300 and 450 nm, which mirrored differences in light transmission through their respective storage solutions. Light transmission through partial-thickness irradiated donor lenticules was greatest across all wavelengths. All corneal tissues exhibited higher transmission than acrylic IOL implant across all wavelengths.

CONCLUSIONS

Gamma-irradiated donor lenticules are comparable with fresh corneas regarding light transmission, with both partial-thickness and full-thickness lenticules having greater transmission than standard IOL. We would expect the optical performance of gamma-irradiated donor lenticules to be comparable to fresh cornea if used for lamellar corneal procedures that do not require a viable endothelium.

Spontaneous long-term course of persistent peripheral graft detachments after Descemet's membrane endothelial keratoplasty

BACKGROUND

Peripheral corneal graft detachment after Descemet's membrane endothelial keratoplasty (DMEK) is a frequently occurring postoperative complication. The natural course of these persistent peripheral detachments over time is not known.

METHODS

166 patients were surveyed by slit-lamp-adapted optical coherence tomography (SL-OCT) directly after surgery, during first postoperative week, 4 weeks, 3, 6 and 12 months, postoperatively. Patients with a persistent peripheral graft detachment 4 weeks after DMEK (n=16) were observed for their spontaneous course up to 1 year postoperatively.

RESULTS

Persistent graft detachments could be characterised into two phenotypes: peripheral roll (n=11; 69%) and laminar detachment (n=5; 31%). Maximal length of the detachment did not change in peripheral rolls during observation period (12 months vs 4 weeks, 578±122 µm vs 593±106 µm, p=0.74), whereas laminar detachments spontaneously attached to the host's stroma (12 months vs 4 weeks, 0 µm vs 1088±295 µm, p≤0.001). Central corneal thickness and (peripheral) corneal thickness above the detached area did not significantly change in either group.

CONCLUSIONS

Persistent peripheral graft detachments after DMEK occurred in 10% of patients and had two distinct OCT-phenotypes. Peripheral rolls did not change during the first 12 months, postoperatively. By contrast, peripheral laminar detachments attached spontaneously even months after surgery. Corneal thickness reduction was only observed above peripheral laminar detachment, but not above peripheral rolls.

Analysis of the changes in keratoplasty indications and preferred techniques

Background

Recently, novel techniques introduced to the field of corneal surgery, e.g. Descemet membrane endothelial keratoplasty (DMEK) and corneal crosslinking, extended the therapeutic options. Additionally contact lens fitting has developed new alternatives. We herein investigated, whether these techniques have affected volume and spectrum of indications of keratoplasties in both a center more specialized in treating Fuchs’ dystrophy (center 1) and a second center that is more specialized in treating keratoconus (center 2).

Methods

We retrospectively reviewed the waiting lists for indication, transplantation technique and the patients’ travel distances to the hospital at both centers.

Results

We reviewed a total of 3778 procedures. Fuchs’ dystrophy increased at center 1 from 17% (42) to 44% (150) and from 13% (27) to 23% (62) at center 2. In center 1, DMEK increased from zero percent in 2010 to 51% in 2013. In center 2, DMEK was not performed until 2013. The percentage of patients with keratoconus slightly decreased from 15% (36) in 2009 vs. 12% (40) in 2013 in center 1. The respective percentages in center 2 were 28% (57) and 19% (51). In both centers, the patients’ travel distances increased.

Conclusions

The results from center 1 suggest that DMEK might increase the total number of keratoplasties. The increase in travel distance suggests that this cannot be fully attributed to recruiting the less advanced patients from the hospital proximity. The increase is rather due to more referrals from other regions. The decrease of keratoconus patients in both centers is surprising and may be attributed to optimized contact lens fitting or even to the effect corneal crosslinking procedure.

Secondary descemet membrane endothelial keratoplasty after failed primary descemet membrane endothelial keratoplasty: clinical results

PURPOSE

To evaluate the clinical outcome of a secondary Descemet membrane endothelial keratoplasty (DMEK) to manage graft failure after primary DMEK.

METHODS

Retrospective analysis of graft failure after primary DMEK treated with a second DMEK. The clinical outcome was evaluated by comparing the pre- to postoperative best-corrected visual acuity (BCVA) after first and second DMEK.

RESULTS

In 122 DMEKs performed, 6 patients were included because of nonclearing edema or graft detachment. Ten of 122 grafts failed, 8 had a second DMEK, and 6 had an adequate follow-up with visual potential to be included in the visual acuity analysis. All patients had Fuchs dystrophy as the underlying disease for the endothelial decompensation. Average time to the second surgery was 2.9 months (1-5 months). Mean follow-up after second DMEK was 3.3 months (1-6 months). BCVA was 0.63 ± 0.22 logarithm of the minimum angle of resolution (logMAR) preoperatively and decreased to 1.50 ± 0.28 logMAR after first surgery (mean follow-up, 2.9 months; P < 0.001). BCVA increased to 0.13 ± 0.05 after successful second DMEK (mean follow-up, 3.3 months; P < 0.001). All second DMEKs were successful.

CONCLUSIONS

To manage DMEK cases with graft failure, secondary DMEK may be a feasible procedure potentially resulting in full visual rehabilitation, as in primary DMEK. In the event of a DMEK graft failure, a secondary DMEK may be an effective back-up procedure because it may give a clinical outcome similar to that given after a primary DMEK.

[Prevention and management of complications in Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK)]

BACKGROUND

Posterior lamellar keratoplasty, in the form of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK), has become a standard procedure for therapy of endothelial diseases of the cornea. The aim of this article is to describe strategies to prevent and manage complications in DMEK and DSAEK surgery.

METHODS

The article is based on a PubMed literature search and own clinical data. Key words used were "DMEK", "DSAEK", "Descemet membrane endothelial keratoplasty" and "Descemet stripping automated endothelial keratoplasty".

RESULTS

The DMEK and DSAEK procedures are safe surgical strategies for treating endothelial corneal diseases if the indications are made correctly.

CONCLUSIONS

The DMEK procedure is the standard procedure for improvement of visual acuity especially for younger patients with Fuchs' dystrophy and DSAEK is particularly suitable for eyes with complicated anterior chamber situations.

Descemet membrane endothelial keratoplasty in cases with existing scleral-sutured and iris-sutured intraocular lenses

Background

To report two cases of Descemet Membrane Endothelial Keratoplasty (DMEK) in patients with existing scleral-fixated and iris-fixated intraocular lenses (sf-IOL and if-IOL, respectively).

Case presentation

DMEK procedures were performed on a 49-year-old woman with a pre-existing sf-IOL (case 1) and a 69-year-old woman with a pre-existing if-IOL (case 2) in order to treat secondary corneal edema due to pseudophakic bullous keratopathy. Visual acuity, refractive error, intraocular pressure, slit lamp examination, pachymetry measurements and endothelial cell density (ECD) were considered and repeated during follow-ups.

Both cases had no intraoperative complications. At postoperative day 1 graft centration and complete attachment were noted. The IOL positions were unchanged in comparison to their preoperative positions. In case 1, visual acuity improved from 1/15 at 1 meter preoperative to 20/200 within one week and to 20/63 within 12 weeks of follow up. In case 2, visual acuity improved from counting fingers at 1 meter preoperative to 20/200 within one week and to 20/100 within 12 weeks of follow-up. In case 2 a partial graft dislocation was observed at postoperative day twenty. Complete graft re-apposition was achieved by rebubbling procedure performed with intracameral air injection.

Conclusions

DMEK surgery in the treatment of pseudophakic bullous keratopathy in the presence of sf-IOL and if-IOL can successfully be performed. These eyes are at increased risk of IOL dislocation into the vitreous cavity during DMEK surgery.

Endothelial cell microRNA expression in human late-onset Fuchs' dystrophy

PURPOSE

MicroRNAs (miRNAs) are a class of endogenous noncoding RNA and post transcriptionally modulate gene expression during development and disease. Our study investigated the differential miRNA expression in human Fuchs' endothelial corneal dystrophy (FECD) compared with normal endothelium to identify miRNA sequences that are involved in the pathogenesis of FECD.

METHODS

Comparative miRNA expression profiles of endothelial samples obtained from FECD patients during lamellar corneal transplant surgery and from normal donor globes were generated using OpenArray plate technology. Differential expression of individual miRNAs was validated in the original and in independent samples using stem-loop RT qPCR assays. Expression of miRNA target genes was assessed using qPCR and tissue microarray (TMA) immunolabeling.

RESULTS

Our results demonstrate downregulation of 87 miRNAs in FECD compared with normal endothelium (>3-fold change; P < 0.01). Correspondingly, DICER1, (encoding an endoribonuclease critical to miRNA biogenesis) showed a moderate but significant decrease in FECD samples (P < 0.05). Significant repression of three miR-29 family members (miR-29a-3p, miR-29b-2-5p, and miR-29c-5p) was paralleled by upregulation of their extracellular matrix associated mRNA targets collagen I and collagen IV. Tissue microarray immunolabeling showed histologically verifiable subendothelial collagen I and collagen IV deposition and increased endothelial laminin protein expression in FECD samples.

CONCLUSIONS

The present study provides the first miRNA profile in FECD and normal endothelial cells and demonstrates widespread miRNA downregulation in FECD. Decreased endothelial expression of miR-29 family members may be associated with increased subendothelial extracellular matrix accumulation in FECD.

Autologous tragal perichondrium transplantation: a novel approach for the management of painful bullous keratopathy

PURPOSE

To introduce autologous tragal perichondrium transplantation as a novel surgical modality for the management of intractable symptomatic bullous keratopathy.

METHODS

In three eyes of three patients with painful bullous keratopathy, autologous tragal perichondria were transplanted on the corneal surface with the human amniotic membrane transplanted above. We included an additional three eyes of three patients with painful bullous keratopathy who received amniotic membrane transplantation only to serve as controls. Clinical symptom outcomes were assessed using a visual analogue scale at postsurgical months 1, 3, 5, 7, and 9. In addition, transplanted tragal perichondrium and amniotic membrane complex tissue button obtained from one patient who underwent penetrating keratoplasty was evaluated by immunohistochemical analysis of CD34, vimentin, and alcian blue staining.

RESULTS

All three patients who underwent autologous tragal perichondrium and human amniotic membrane co-transplantation showed improvements in pain and tearing. However, all three patients in the control group experienced aggravation of tearing and no further improvement of pain 3 months after surgery. In addition, one patient in the control group developed premature degradation of the amniotic membrane. Histopathologic and immunohistochemical analysis showed intact surface epithelization and positive CD34, vimentin and alcian blue staining of transplanted tragal perichondria.

CONCLUSIONS

The tragal perichondrium has a high mechanical structural force and high potency due to well-organized epithelization and the presence of mesenchymal stem cells. Autologous tragal perichondrium transplantation may be an effective modality for the management of painful bullous keratopathy.

Split cornea transplantation: relationship between storage time of split donor tissue and outcome

PURPOSE

To analyze the relationship between storage time of split donor tissue and outcomes after deep anterior lamellar keratoplasty (DALK) and Descemet's membrane endothelial keratoplasty (DMEK).

DESIGN

Retrospective analysis of a nonrandomized, consecutive, interventional case series.

PARTICIPANTS

One hundred ten eyes with anterior stromal disease suitable for DALK and 110 eyes with endothelial disease suitable for DMEK underwent surgically successful split cornea transplantation combining both procedures within 7 days after splitting.

METHODS

Split donor storage times (splitting to grafting) and total storage times (death to grafting) were correlated with the 1-year functional and morphologic outcomes after DALK and DMEK surgery using a Spearman correlation coefficient and a Mann-Whitney U test.

MAIN OUTCOME MEASURES

Best spectacle-corrected visual acuity (BSCVA), endothelial cell density, and complication rates within 12 months of follow-up.

RESULTS

The mean split donor storage time was 35 ± 47 hours (range, 0-162 hours) after splitting for anterior donor grafts and 21 ± 40 hours (range, 0-158 hours) for posterior grafts. The mean total storage time was 352 ± 108 hours (range, 108-678 hours) for anterior lamellas and 339 ± 109 hours (range, 96-630 hours) for posterior lamellas. One year after DALK, the mean BSCVA was 20/30 (range, 20/50-20/20), endothelial cell loss was 8% (range, 2%-16%), and the complication rate (Descemet's folds, epitheliopathy, loose sutures) was 18%. One year after DMEK, the mean BSCVA was 20/25 (range, 20/40-20/16), endothelial cell loss was 41% (range, 17%-63%), and the complication rate (partial graft detachment) was 62%. For DALK and DMEK, no significant association was observed between split donor storage time as well as total storage time and BSCVA (P ≥ 0.409), endothelial cell loss (P≥0.236), or complication rate (P ≥ 0.647) within 1 year of follow-up.

CONCLUSIONS

Anterior and posterior donor tissue may be stored safely for up to 1 week in organ culture before use in DALK and DMEK surgery. This simplifies the clinical feasibility of split cornea transplantation to reduce donor shortage and cost in corneal transplantation in the future.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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.

An in depth analysis of histopathological characteristics found in keratoconus

AIMS

The aims of this study were to re-assess the histopathology of the disease by introducing more modern measuring techniques and to determine if axial stromal thinning, which is the most apparent change, is related to the other alterations observed.

METHODS

Recipient keratoconic corneas from 36 patients following corneal transplantation were studied. Haematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining were used to identify breaks in Bowman's layer and Descemet's membrane. Thickness of corneal layers was measured by Leica QWin software. Epithelial and stromal thickness were measured in each sample at the periphery of the corneal button and at the area of maximal stromal thinning. The presence of apoptotic cells in Bowman's layer breaks was detected by terminal deoxynucleotidyl transferase mediated dUTP-X nick end labelling.

RESULTS

In all 36 corneal samples the central stroma, at the apex of the cone, was thinner than the peripheral. There was a negative correlation between central stromal and central epithelial thickness (p = 0.009). Bowman's layer breaks were found in 92% of corneas. Apoptotic cells were detected at the level of Bowman's breaks membrane. We found a positive correlation between epithelial thickness and the number of Bowman's layer breaks (p = 0.009 for central epithelial thickness and p = 0.003 for peripheral epithelial thickness). Descemet's membrane deformities were observed in 19% of corneas and central stromal thickness of these corneas was significantly less than corneas without breaks (p = 0.006).

CONCLUSIONS

There are various different histopathological features associated with keratoconus and some of them are very subtle and not very well studied. Accurate measurements also suggest some correlations between them. Stromal thinning is associated with the number of breaks in Descemet's membrane, but it is the thickening of the epithelium which is associated with breaks in Bowman's layer.

Downregulation of β-actin gene and human antigen R in human keratoconus

PURPOSE

The purpose of this study was to determine the expression levels and regulation of β-actin in the stroma of keratoconus (KC) and normal corneas.

METHODS

A total of 15 different human corneas from both KC and normal individuals were used for this study. Additionally, 3 Fuch's dystrophic corneas were also used. The β-actin gene expression was analyzed at the transcriptional and translational levels in the epithelium and stroma of the KC and normal corneas. The human antigen R (HuR) gene expression was analyzed by real-time PCR in the stroma of five KC and five normal corneas. The keratocytes from three normal and three KC corneas were cultured in the presence of serum, and the expression levels of β-actin and human antigen R (HuR) were analyzed by using confocal imaging in both normal and KC fibroblasts.

RESULTS

The expression of the β-actin gene was downregulated in the stroma of the six KC corneas but not in the stroma of six normal and Fuchs' dystrophic corneas. Immunofluorescence detection of β-actin showed that it was absent in the KC fibroblast. The real-time PCR analysis of the HuR gene showed a relative 4.7-fold lower expression in KC corneas relative to the normal corneas, which was further confirmed by the immunofluorescence detection of HuR in fibroblasts of KC corneas.

CONCLUSIONS

Although ubiquitous β-actins are essential for cell survival during early embryogenesis, the effects on various stages of development are not well understood. Our results show that β-actin is downregulated in the corneal stroma of patients with KC, which may be related to reduced levels of a stabilizing factor (HuR) for β-actin mRNA. We propose that loss of β-actin in the corneal stroma might be a triggering factor in the development of KC.

Descemet membrane endothelial keratoplasty versus descemet stripping automated endothelial keratoplasty

PURPOSE

To evaluate visual outcome and endothelial cell survival after Descemet membrane endothelial keratoplasty (DMEK) in comparison with Descemet stripping automated endothelial keratoplasty (DSAEK).

DESIGN

Single-center, retrospective, consecutive case series.

METHODS

Thirty-eight eyes of 38 consecutive patients undergoing DMEK, who completed a 6-month follow-up, were compared with 35 eyes of 35 consecutive patients undergoing DSAEK for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy. Main outcome measures included best-corrected visual acuity (in logarithm of the minimal angle of resolution [logMAR] units) and endothelial cell density within a 6-month follow-up.

RESULTS

Best-corrected visual acuity increased from 0.70 ± 0.48 logMAR and 0.75 ± 0.32 logMAR before surgery to 0.21 ± 0.14 logMAR and 0.48 ± 0.19 logMAR 3 months after DMEK and DSAEK (P < .001), respectively, and to 0.17 ± 0.12 logMAR and 0.36 ± 0.15 logMAR 6 months after DMEK and DSAEK (P < .001), respectively. Endothelial cell density decreased from 2575 ± 260 cells/mm(2) and 2502 ± 220 cells/mm(2) before surgery to 1498 ± 244 cells/mm(2) and 1778 ± 420 cells/mm(2) 3 months after DMEK and DSAEK (P < .001), respectively, and to 1520 ± 299 cells/mm(2) and 1532 ± 495 cells/mm(2) 6 months after DMEK and DSAEK (P = .483), respectively. Central corneal thickness decreased from 652 ± 92 μm before surgery to 517 ± 45 μm 6 months after DMEK, and from 698 ± 137 μm before surgery to 618 ± 66 μm 6 months after DSAEK.

CONCLUSIONS

DMEK provided faster and more complete visual rehabilitation when compared with DSAEK. However, there were no significant differences concerning endothelial cell survival within a 6-month follow-up.

Split cornea transplantation for 2 recipients - review of the first 100 consecutive patients

PURPOSE

To evaluate the feasibility of split cornea transplantation for 2 recipients by combining deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK).

DESIGN

Interventional case series.

METHODS

Fifty consecutive eyes with anterior stromal disease suitable for DALK and 50 eyes with endothelial disease suitable for DMEK were scheduled for split cornea transplantation combining both procedures within 72 hours. Main outcome measures included success of using a single donor cornea for 2 recipients, best spectacle-corrected visual acuity (BSCVA), and complication rates within 6 months' follow-up.

RESULTS

A single donor cornea could be used for 2 recipients in 47 cases (94%). In 3 eyes (6%), the DALK procedure had to be converted to penetrating keratoplasty (PK) requiring a full-thickness corneal graft. Thereby, 47 donor corneas (47%) could be saved. Six months after surgery, mean BSCVA was 20/36 in the 47 eyes that underwent successful DALK, 20/50 in the 3 eyes that underwent conversion from DALK to PK, and 20/29 in the 50 eyes that underwent DMEK. Postoperative complications after DALK included Descemet folds in 5 eyes (11%) and epitheliopathy in 3 eyes (6%). After DMEK, partial graft detachment occurred in 26 eyes (52%) and was managed successfully with intracameral air reinjection. All corneas remained clear up to 6 months after surgery. No intraocular infections occurred.

CONCLUSION

Split use of donor corneal tissue for combined DALK and DMEK procedures in 2 recipients within 3 subsequent days is a feasible approach to reduce donor shortage in corneal transplantation in the future.

Changing indications for penetrating keratoplasty in Greece, 1982-2006: a multicenter study

PURPOSE

To evaluate the leading indications for penetrating keratoplasty (PKP) and their trends in Greece during the period 1982 to 2006.

METHODS

Retrospective data review of 1,929 patients (2233 eyes) who underwent PKP in the period between 1982 and 2006 at three cornea transplantation units of three hospitals in Greece (Athens General Hospital, Heraklion University Hospital of Crete, and Thessaloniki University Hospital). Indications were classified into nine different groups: keratoconus, herpes simplex keratitis, microbial (nonviral) keratitis (fungal, bacterial, and acanthamoeba), aphakic/pseudophakic corneal edema, posttraumatic corneal scars, chemical/thermal injury, regraft, Fuchs' endothelial dystrophy, and other.

RESULTS

The leading indications for PKP, in order of decreasing frequency, were aphakic/pseudophakic corneal edema (n = 649 [29.1%]), keratoconus (n = 580 [26%]), regraft (n = 265 [11.9%]), microbial (nonviral) keratitis (n = 188 [8.4%]), posttraumatic corneal scar (n = 171 [7.7%]), herpes simplex keratitis (n = 104 [4.6%]), Fuchs' endothelial dystrophy (n = 104 [4.6%]), chemical/thermal injury (n = 61 [2.7%]), and other (n = 111 [5%]). The prevalence of regrafts as an indication for PKP increased during the study period.

CONCLUSIONS

Aphakic/pseudophakic corneal edema was the most common indication for PKP in a multicenter series in Greece followed by keratoconus. The number of regrafts dramatically increased during the 25-year period.

Split cornea transplantation for 2 recipients: a new strategy to reduce corneal tissue cost and shortage

PURPOSE

To evaluate the feasibility of using a single donor cornea for 2 recipients by combining deep anterior lamellar keratoplasty (DALK) and Descemet's membrane endothelial keratoplasty (DMEK) surgeries on the same day.

DESIGN

Single-center, nonrandomized, prospective, interventional case series.

PARTICIPANTS

Twelve consecutive donor corneas were scheduled for split cornea transplantation combining DALK for a keratoconus patient and DMEK for a Fuchs' endothelial dystrophy patient on the same surgery day.

METHODS

First, a big-bubble DALK procedure was performed for the keratoconus eye. When bare Descemet's membrane was prepared successfully requiring no conversion to penetrating keratoplasty (PK), then during surgery the donor, endothelium-Descemet's membrane layer was removed and stored for subsequent DMEK in a second patient, and the remaining anterior lamella of the donor cornea was used to complete the DALK surgery. Afterward, a DMEK procedure was performed on the second patient with Fuchs' endothelial dystrophy, grafting the stored endothelium-Descemet's membrane layer of the original donor button.

MAIN OUTCOME MEASURES

Success of using a single donor cornea for 2 recipient eyes, best spectacle-corrected visual acuity (BSCVA), and complication rates within 6 months follow-up.

RESULTS

A single donor cornea could be used for 2 recipients in 10 of 12 donor buttons (83%). In 2 cases (17%), the DALK procedure had to be converted to PK requiring a full-thickness corneal graft. Therefore, 10 donor corneas (45%) could be saved. Six months after surgery, mean BSCVA was 20/35 (range, 20/50-20/25) in 10 eyes that underwent successful DALK, 20/50 (range, 20/63-20/40) in 2 eyes that underwent conversion from DALK to PK, and 20/31 (range, 20/50-20/16) in 10 eyes that underwent DMEK. Postoperative complications after DALK included Descemet's folds in 3 eyes (30%) and epitheliopathy in 2 eyes (20%). After DMEK, partial graft detachment occurred in 5 eyes (50%) and was managed successfully with intracameral air reinjection. All corneas remained clear up to 6 months after surgery.

CONCLUSIONS

Split use of donor corneal tissue for combined DALK and DMEK procedures in 2 recipients on the same surgery day is a promising strategy to reduce donor shortage and cost in corneal transplantation surgery in the future.

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.

GS-101 antisense oligonucleotide eye drops inhibit corneal neovascularization: interim results of a randomized phase II trial

PURPOSE

Pathologic corneal neovascularization not only reduces corneal transparency and visual acuity, but also is one of the most significant preoperative and postoperative risk factors for graft rejection after corneal transplantation. The aim of this study was to test tolerability and efficacy of gene signal (GS)-101 eye drops, an antisense oligonucleotide against insulin receptor substrate-1, versus placebo on inhibition of progressive corneal neovascularization.

DESIGN

Randomized, double-blind, multicenter, phase II clinical study.

PARTICIPANTS AND CONTROLS

Interim analysis on 40 patients with progressive corneal neovascularization resulting from various underlying diseases being nonresponsive to conventional therapy.

INTERVENTIONS

Four groups of 10 patients were treated for 3 months in this dose-finding study comparing 3 doses of GS-101 (eye drops twice daily; 43, 86, and 172 microg/day total) with placebo (10 patients per group).

MAIN OUTCOME MEASURES

The primary end point was the area covered by pathologic corneal blood vessels, which was measured morphometrically on digitized slit-lamp pictures using image analysis techniques.

RESULTS

GS-101 eye drops were well tolerated. All serious and 95% of all other adverse events were categorized by the investigators as unrelated. In 3 patients, there was a potentially related side effect of ocular surface discomfort. At a dose of 86 microg/day (43 microg/drop), GS-101 eye drops produced a significant inhibition and regression of corneal neovascularization (-2.04+/-1.57% of total corneal area; P = 0.0047), whereas the low dose tended to stabilize it (0.07+/-2.94%; P = 0.2088) compared with placebo (0.89+/-2.15%), where corneal neovascularization progressed in all patients. There was no apparent benefit to the higher dose (1.60+/-7.63%).

CONCLUSIONS

The interim results of this phase II study suggest that GS-101 eye drops at an optimal dose of 86 microg/day are an effective and noninvasive approach specifically to inhibit and regress active corneal angiogenesis, a major risk factor for corneal graft transplantation and graft rejection. Safety concerns were not detected.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Histopathological Diagnosis of Corneal Button Specimens: An Epidemiological Study

PURPOSE

To determine the most common histopathological diagnosis of corneal specimens from penetrating keratoplasty (PKP).

METHODS

The records of 500 corneal specimens submitted to biopsy at the Henry Witelson Ocular Pathology Laboratory, Montreal, Canada, from 1999 to 2004 were reviewed. Age, sex, clinical indications, and histopathological findings were analyzed.

RESULTS

Chronic keratitis (45.6%) was the most common pathological diagnosis, followed by corneal edema (25.8%), dystrophy (12.8%), keratoconus (KC) (9.2%), acute keratitis (5.6%), and degeneration (1.0%). Among the specimens with chronic keratitis, regraft was the most common clinical indication (39.0%). In the group of acute keratitis, ulcerative condition was the leading cause (75,0%). Fuchs' endothelial dystrophy represented 79.7% of the clinical diagnoses in the group of corneal dystrophies. The median patient age was 70-79 years, and the gender distribution was nearly symmetric.

CONCLUSION

The present study is important for determining the most common histopathological diagnoses of corneal button specimens and the correlation with the age, gender, and clinical indications of PKP.