Nineteen years of penetrating keratoplasty in the Hotel-Dieu Hospital in Paris

Modified big bubble technique for deep anterior lamellar keratoplasty in keratoconus

We describe a modified technique for deep anterior lamellar keratoplasty with three modifications in big bubble pneumodissection technique; including two staged stromal trephination to avoid inadvertent full-thickness trephination, deep bevel-up needle air injection for better visualization and deeper air injection and, vicoseperation by refilling the pre-Descemet space with a viscoelastic after removing the air bubble for safe removal of the deep stromal layers. Patients with advanced keratoconus underwent deep anterior lamellar keratoplasty with pneumodissection by two-staged trephination followed by bevel-up needle deep air injection and viscoseperation. The big bubble was successfully formed in all cases and there was no case with the rupture of the Descemet's membrane (DM) during air injection or baring of DM.

Incidence of wound dehiscence after keratoplasty: a meta-analysis of observational studies

Background

The comprehensive investigation of the association between keratoplasty and wound dehiscence remains limited, despite corneal disease being a leading cause of visual impairment.

Methods

A meticulous search strategy was executed across prominent databases such as Web of Science, PubMed, Cochrane Library, and Embase. Data relevant to our research objective were extracted from eligible studies. The methodological quality of each study was assessed using the ROBINS-I tool, while statistical analysis was conducted utilizing STATA 17.0. To evaluate potential publication bias, the Funnel plot and Egger's test were employed.

Results

A total of 11 articles were deemed suitable for inclusion in our analysis. Our findings indicate that the overall incidence of wound dehiscence following keratoplasty was estimated to be 1.9% (95% CI: 0.013, 0.026), although substantial heterogeneity was observed (I2 = 72.798%). Notably, developed countries exhibited a higher incidence of wound dehiscence compared to their developing counterparts. Furthermore, the occurrence of wound dehiscence was found to be lower in deep anterior lamellar keratoplasty (DALK) procedures when compared to penetrating keratoplasty (PK). Analysis utilizing Egger's linear regression method yielded no evidence of publication bias (p = 0.91). Moreover, within the first year post-keratoplasty, approximately 31.4% of patients experienced wound dehiscence (95% CI: 0.149, 0.503), and 43.1% exhibited a decline in best-corrected visual acuity (BCVA) (95% CI, 0.341, 0.522).

Conclusion

The results of our study unveiled the occurrence rate of wound dehiscence following keratoplasty, exhibiting variations based on economic level and the specific surgical procedure employed. Furthermore, onset time of wound dehiscence and visual acuity warrant consideration.

Recurrent Keratoconus: Corneal Transplants for Keratoconus Develop Tomographic Ectatic Changes

PURPOSE

The purpose of this study was to evaluate postoperative Scheimpflug imaging changes during the first 5 years after penetrating keratoplasty (PK) in patients with keratoconus (KC).

METHODS

This retrospective, interventional case series includes 31 eyes of 31 patients who underwent their first PK with a history of KC. Postoperative Scheimpflug imaging was performed 3 months after the removal of the last suture (baseline) and then repeated 3 and 5 years after the PK. Demographic data, donor and host trephination diameter, and Scheimpflug imaging (Pentacam HR, Oculus, Germany) parameters indicative of ectasia were analyzed to evaluate postoperative graft changes that occur after PK.

RESULTS

The maximal keratometry (Kmax) progressed significantly between baseline (53.5 ± 6.1 D) and postoperative year 3 and year 5 [56.5 ± 6.1 diopter (D) and 58.8 ± 7.9 D, P < 0.001]. Significant changes were also observed for the anterior best fit sphere and posterior best fit sphere ( P < 0.001 for 3 and 5 years compared with baseline). Kmax increased by at least 2 Ds for 74.2% of patients and up to 7 Ds or more for 25.8% of the patients. A significant inverse correlation was observed for host trephine size and progression of Kmax (r = -0.52, P = 0.01), which indicated that larger host trephination size was associated with a smaller increase in postoperative Kmax.

CONCLUSIONS

Tomographic graft changes indicative of ectasia were observed within 3 to 5 years after PK in patients with KC. These changes were observed more frequently and sooner after corneal transplants than previously reported.

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.

Clinical Characteristics and Outcomes of Short-term Repeat Corneal Transplantation

PURPOSE

To explore the primary indications, direct causes and graft survival of short-term repeat keratoplasty.

METHODS

An analytical cross-sectional study.

RESULTS

The primary indications for keratoplasty were infectious keratitis (67.9%) and immune keratopathy (12.8%). The direct causes of graft failure were infectious ulcer (43.6%) and recurrence (30.8%). Pre-operative hypopyon (P = 0.017, HR = 1.757) and use of decellularized porcine corneas as grafts (P = 0.005, HR = 2.690) were independent risk factors for graft failure. The Kaplan-Meier analysis revealed that the 1-year survival rate of 88 repeat grafts was 85.2%, and the 5-year survival rate was 79.2%. The survival rates of the repeat grafts were significantly higher than those of the first grafts (P < 0.001).

CONCLUSION

Infectious keratitis is the most common indication of short-term graft failure and is often failed by infectious ulcer and keratitis recurrence. While the decellularized porcine cornea is a promising application in developing countries, certain difficulties, such as graft melting, remain unresolved.

Indications and Surgical Techniques for Corneal Transplantation at a Tertiary Referral Center

Purpose

The study aimed to review the indications and techniques for corneal transplantation at a tertiary referral center over a 5-year period.

Methods

Records of patients who underwent corneal transplantation at Khalili Medical Center, Shiraz, Iran from September, 2012 to September, 2017 were reviewed.

Results

A total of 1149 eyes of 956 patients underwent corneal transplantation. The most common indication was infectious corneal ulcers (n = 296, 25.8%), followed by keratoconus (n = 243, 21.1%), bullous keratopathy (n = 219, 19.1%), failed grafts (n = 117, 10.2%), non-herpetic corneal scars (n = 113, 9.8%), corneal stromal dystrophies (n = 33, 2.9%), pellucid marginal degeneration (n = 31, 2.7%), and trauma (n = 26, 2.3%); other indications included thin descemetocele, post-herpetic corneal scar, endothelial corneal dystrophies, anterior segment dysgenesis, corneal ectasia after laser in situ keratomileusis, and corneal fibrosis. Corneal transplantation techniques included penetrating keratoplasty (PKP, n = 789, 68.7%), deep anterior lamellar keratoplasty (DALK, n = 187, 16.3%), Descemet's stripping automated endothelial keratoplasty (n = 171, 14.9%), and keratolimbal allograft (n = 2, 0.1%) in descending order. In children (aged ≤18 years), the most common indication was keratoconus (n = 32, 41.6%), and the most common technique was PKP (n = 50, 64.9%). In patients aged 19-27 years, the most common indication was keratoconus (n = 89, 64.5%), and the most common technique was PKP (n = 75, 54.4%).

Conclusion

Infectious corneal ulcer was the most common indication, and PKP was the most prevalent technique in patients undergoing corneal transplantation. DALK was an emerging alternative surgical treatment in patients with corneal disorders in which corneal endothelium is spared.

Corneal transplantation trends in France from 2004 to 2015: A 12-year review

Purpose:

The aim of this study was to report the 12-year longitudinal trends in indication and corneal transplantation techniques in France from 2004 to 2015.

Results:

The records of all corneal transplantations performed from 2004 to 2015 in France were retrospectively reviewed. The patient indications and types of transplant performed were analyzed. A total of 46,658 corneal transplantations were performed between 2004 and 2015, with 34,187 (73.3%) penetrating keratoplasty and 10,452 (22.4%) lamellar keratoplasty. The leading surgical indications were secondary endothelial failure (24.3%), keratoconus (18.8%), regraft (13.5%), and Fuchs endothelial corneal dystrophy (15.1%). Endothelial keratoplasty became the preferred technique for endothelial diseases and deep anterior lamellar keratoplasty the preferred technique for keratoconus, surpassing penetrating keratoplasty in 2013.

Conclusion:

Secondary endothelial failure is the top indication for performing a keratoplasty over the 12-year period. There was a shift from penetrating keratoplasty to endothelial keratoplasty performed for Fuchs endothelial corneal dystrophy and secondary endothelial failure, and to deep anterior lamellar keratoplasty, performed for keratoconus. This highlights an important shift in managing corneal diseases toward the application of selective and more conservative surgeries and changes in indications in corneal transplantation.

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).

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.

[Corneal transplantation: study carried out at the Department of Ophthalmology, University Hospital Center Mohammed VI, Marrakech]

La kératoplastie transfixiante est l'une des plus fréquentes des greffes de tissus et transplantations d'organes. Le but de notre travail est de rapporter notre expérience en matière de greffe de cornée. C'est une étude prospective de 195 patients ayant bénéficié d'une greffe de cornée sur une période allant d'aout 2009 à Août 2015. Le recul moyen est de 21 mois. Les indications de la greffe étaient le kératocône 33.8%, les séquelles de traumatisme 10.7%, la kératopathie bulleuse 19.5%, les dystrophies héréditaires 10.7%, et les kératites herpétiques 9.2%. L'acuité visuelle initiale était inférieure à 1/10 dans 90% des cas. Nous avons observé une réaction de rejet dans 19 yeux dont 14 étaient récupérables, 33 hypertonies oculaires, 20cataracte, et 2 décollements descmetiques. La greffe de cornée apparaît comme une intervention donnant de bons résultats anatomiques et fonctionnels. Les résultats ne doivent pas occulter une surveillance post opératoire étroite et régulière pour dépister à temps d’éventuelles complications, en particulier le rejet de greffe.

Changing trends in corneal graft surgery: a ten-year review

AIM

To review indications and corneal tissue use for penetrating and lamellar surgery between 2002 and 2011.

METHODS

The surgical reports of corneal grafts performed during 2002-2011, using tissues supplied by the Eye Bank of Piedmont (Italy), were reviewed retrospectively. Patient demographic data, date of intervention, indication for surgery, and surgical technique used were recorded. Surgical techniques included penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK) and endothelial keratoplasty (EK). The χ (2) test was used to compare the distribution of indications and types of surgical technique used, for corneal grafts done during 2002-2006 versus those done during 2007-2011.

RESULTS

The number of corneal grafts increased by 30.7% from 2002-2006 to 2007-2011 (from 1567 to 2048). Comparing the two periods, both main indications and surgical techniques changed significantly. In 2007-2011, the proportion of interventions for aphakic/pseudophakic bullous keratopathy (from 16.8% to 21.3%), graft failure (from 16.4% to 19.1%) and Fuchs endothelial dystrophy (from 12.8% to 16.7%) all increased significantly (P<0.05), while those for keratoconus decreased significantly (from 35.6% to 27.3%; P<0.001). In 2007-2011, the proportion of PK decreased significantly (from 92.4% to 57.2%; P<0.001) while that of EK and DALK went from 0.4% to 30.2% (P<0.001) and from 7.2% to 12.6% (P<0.001) respectively.

CONCLUSION

During 2002-2011 the number of interventions increased significantly for corneal endothelial diseases and graft failure. The growing demand for interventions for these diseases corresponded to the widespread adoption of EK techniques. The use of DALK also increased, but more moderately than EK procedures.

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.

Keratoconus: tissue engineering and biomaterials

Keratoconus (KC) is a bilateral, asymmetric, corneal disorder that is characterized by progressive thinning, steepening, and potential scarring. The prevalence of KC is stated to be 1 in 2000 persons worldwide; however, numbers vary depending on size of the study and regions. KC appears more often in South Asian, Eastern Mediterranean, and North African populations. The cause remains unknown, although a variety of factors have been considered. Genetics, cellular, and mechanical changes have all been reported; however, most of these studies have proven inconclusive. Clearly, the major problem here, like with any other ocular disease, is quality of life and the threat of vision loss. While most KC cases progress until the third or fourth decade, it varies between individuals. Patients may experience periods of several months with significant changes followed by months or years of no change, followed by another period of rapid changes. Despite the major advancements, it is still uncertain how to treat KC at early stages and prevent vision impairment. There are currently limited tissue engineering techniques and/or "smart" biomaterials that can help arrest the progression of KC. This review will focus on current treatments and how biomaterials may hold promise for the future.

Indications of penetrating keratoplasty in southern India

AIM

To study the indications of penetrating keratoplasty in Southern India.

SETTINGS AND DESIGN

Retrospective study.

MATERIAL AND METHODS

Retrospective evaluation of eye bank records from December, 2002 to December, 2012 with respect to indications for penetrating keratoplasty.

RESULTS

During the period considered for study, 102 penetrating keratoplasties were performed. The leading indications for penetrating keratoplasty were corneal scarring (60.7%), followed by regrafting (12.7%), spheroidal degeneration (9.8%), aphakic bullous keratopathy (5.88%), pseudophakic bullous keratopathy (2.94%), acute infectious keratitis (2.94%), corneal dystrophy and keratoconus (4.9%). Healed infectious keratitis (72.88%) was the most common subcategory among the eyes with corneal scarring followed by traumatic corneal scars (16.12%).

CONCLUSION

Corneal scarring from healed infectious keratitis are the most common indication for keratoplasty in Southern India.

Changing indications and surgical techniques for corneal transplantation between 2004 and 2009 at a tertiary referral center

Purpose:

The aim of this study is to report the indications, techniques, and clinical outcomes of corneal transplantation and investigate any changing trends in surgical techniques over a 6 year period.

Materials and Methods:

Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran, from January 2004 to December 2009 were reviewed to determine the indications and types of corneal transplantation. Postoperative best-corrected visual acuity, refractive error, graft clarity, and complications were reported.

Results:

During this period, 1859 eyes of 1624 patients with a mean age of 41.3 ± 21.3 years underwent corneal transplantation. The most common indication was keratoconus (38.4%) followed by aphakic/pseudophakic bullous keratopathy (11.7%), previous failed grafts (10.6%), infectious corneal ulcers (10.1%), non-herpetic corneal scars (7.6%), trachoma keratopathy (4.7%), stromal corneal dystrophies (4.6%), post-herpetic corneal scar (3.7%), Fuchs’ endothelial dystrophy (0.8%), and congenital hereditary endothelial dystrophy (0.4%). Techniques of corneal transplantation included penetrating keratoplasty (PKP; 70.9%), deep anterior lamellar keratoplasty (DALK; 20.1%), conventional lamellar keratoplasty (LKP; 4.4%), and Descemet's stripping automated endothelial keratoplasty (DSAEK; 2.3%). Over the study period, there was a significant increase in the relative frequency of infectious corneal ulcers, failed grafts, and trachoma keratopathy. Additionally, a significant reduction was observed in PKP and LKP procedures, and volume of DALK and DSAEK increased significantly. At final follow-up, 69.0% of grafts were clear in the PKP group. This figure was 82.6%, 82.7%, and 97.6% in the DALK, LKP, and DSAEK groups, respectively.

Conclusion:

Keratoconus was the most common indication and PKP was the most prevalent technique used for corneal transplantation. However, significant changes in the indications and surgical techniques were observed from 2004 to 2009.

VSX1 gene and keratoconus: genetic analysis in Korean patients

PURPOSE

The visual system homeobox 1 (VSX1) gene variants have recently been shown to be associated with keratoconus. To replicate this finding, we performed a genetic analysis of the VSX1 gene in a Korean case-control sample.

METHODS

Patients with keratoconus and healthy control subjects were recruited from Seoul National University Hospital. A diagnosis of keratoconus was made based on clinical examinations and the presence of characteristic topographic features. For all patients and controls, the whole coding region and the exon-intron junctions of the VSX1 gene were analyzed by direct sequencing.

RESULTS

Fifty-three patients with keratoconus and 100 healthy volunteers were included. We observed 2 novel missense substitutions (Leu17Val and Val199Leu) and 1 previously reported substitution (Gly160Val) in 6 of the 53 affected probands. Because these substitutions have been identified in unaffected individuals, they were not considered to be pathogenic. No intragenic polymorphism was associated with a significantly increased risk of keratoconus.

CONCLUSIONS

We cannot confirm the previously reported association of the VSX1 gene variants with keratoconus. Our results suggest that the VSX1 gene and its mutations with amino acid changes do not play a major role in the pathogenesis of keratoconus.

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.

Deep anterior lamellar keratoplasty: indications, surgical techniques and complications

The concept of lamellar keratoplasty (LK) is not new. However, it had been abandoned and largely replaced by the time-honored technique of penetrating keratoplasty (PK) because LK is technically demanding, time consuming and gives suboptimal visual outcomes due to interface irregularity arising from manual lamellar dissection. Recent improvements in surgical instruments and introduction of new techniques of maximum depth of corneal dissection as well as inherent advantages such as preservation of globe integrity and elimination of endothelial graft rejection have resulted in a re-introduction of LK as an acceptable alternative to conventional PK. This review article describes the indications, different techniques, clinical outcomes and complications of deep anterior LK.

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.

Deep anterior lamellar keratoplasty versus penetrating keratoplasty for keratoconus: a clinical trial

PURPOSE

To compare deep anterior lamellar keratoplasty (DALK) using the big-bubble technique to penetrating keratoplasty (PK) in patients with keratoconus.

MATERIALS AND METHODS

In this clinical trial, patients with moderate to advanced keratoconus with poor spectacle-corrected visual acuity and intolerant to contact lens wear were enrolled. DALK was performed using the big-bubble technique, and a full-thickness donor cornea without Descemet membrane was sutured to the recipient bed. PK was performed conventionally with a Hessburg-Barron suction trephine. Three types of suturing were used for both groups. Postoperative refractive errors, best-corrected visual acuity (BCVA), contrast sensitivity function (CSF), and higher order aberrations (HOAs) were compared between the study groups.

RESULTS

The study included 81 eyes of 81 patients. Forty-six eyes underwent DALK from which 4 were excluded because of failure to achieve bared Descemet membrane. Thirty-five eyes received PK. Mean patient age was 26.91 ± 7.9 versus 30.89 ± 10.3 years in the DALK and PK groups, respectively (P = 0.06). Mean follow-up period was 22.0 ± 7.9 months in the DALK group and 24.6 ± 3.5 months in the PK group (P = 0.32). Mean postoperative spherical equivalent refractive error was -3.23 ± 3.4 diopters in the DALK group versus -2.22 ± 4.6 diopters in the PK group (P = 0.28), and mean postoperative BCVA was 0.18 ± 0.08 and 0.15 ± 0.10 logarithm of the minimum angle of resolution, respectively (P = 0.12). CSF and total aberrations and HOAs were comparable in the study groups.

CONCLUSIONS

DALK is an effective alternative surgical procedure for patients with keratoconus; the outcomes are comparable to PK in terms of refractive errors, BCVA, CSF, and HOAs.

Keratoconus: a review

Keratoconus is the most common primary ectasia. It usually occurs in the second decade of life and affects both genders and all ethnicities. The estimated prevalence in the general population is 54 per 100,000. Ocular signs and symptoms vary depending on disease severity. Early forms normally go unnoticed unless corneal topography is performed. Disease progression is manifested with a loss of visual acuity which cannot be compensated for with spectacles. Corneal thinning frequently precedes ectasia. In moderate and advance cases, a hemosiderin arc or circle line, known as Fleischer's ring, is frequently seen around the cone base. Vogt's striaes, which are fine vertical lines produced by Descemet's membrane compression, is another characteristic sign. Most patients eventually develop corneal scarring. Munson's sign, a V-shape deformation of the lower eyelid in downward position; Rizzuti's sign, a bright reflection from the nasal area of the limbus when light is directed to the limbus temporal area; and breakages in Descemet's membrane causing acute stromal oedema, known as hydrops, are observed in advanced stages. Classifications based on morphology, disease evolution, ocular signs and index-based systems of keratoconus have been proposed. Theories into the genetic, biomechanical and biochemical causes of keratoconus have been suggested. Management varies depending on disease severity. Incipient cases are managed with spectacles, mild to moderate cases with contact lenses and severe cases can be treated with keratoplasty. This article provides a review on the definition, epidemiology, clinical features, classification, histopathology, aetiology and pathogenesis, and management and treatment strategies for keratoconus.

Deep anterior lamellar keratoplasty in patients with keratoconus: big-bubble technique

PURPOSE

To evaluate the visual and refractive outcomes after deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in eyes with keratoconus.

METHODS

In this case series, eyes with moderate to advanced keratoconus underwent DALK. All of them had unacceptable spectacle-corrected visual acuity or were contact lens intolerant. DALK was performed using the big-bubble technique. Full thickness donor cornea without Descemet's membrane (DM) was sutured to the recipient bed with three different suturing techniques. The visual acuity (presented in logMAR), refractive status, intraoperative and postoperative complications were evaluated.

RESULTS

A total of 129 consecutive eyes of 121 patients were included. In 3 eyes, the operation was converted to penetrating keratoplasty. Therefore, 126 eyes (79 male) were enrolled in the study. Mean patient age at the time of surgery was 26.08 +/- 7.6 years. Mean follow-up period was 21.62 +/- 9.0 months. Mean preoperative corrected visual acuity was 1.27 +/- 0.4 logMAR, increasing to 0.25 +/- 0.2 logMAR at final follow-up examination (P < 0.001). Postoperative mean spherical equivalent refractive error, refractive and keratometric astigmatism were -3.41 +/- 3.1 D, 3.04 +/- 2.3 D, and 3.67 +/- 2.1 D, respectively. Bared DM was achieved in 103 eyes, whereas in 23 eyes pre-Descemet dissection was performed. DM perforation occurred in 5 eyes. The main complications encountered were filamentary keratitis, subepithelial graft rejection, and astigmatism.

CONCLUSIONS

: DALK using the big-bubble technique appears to be a safe and effective procedure for eyes with moderate to advanced keratoconus. In case of extensive intraoperative DM perforation, it does not pose any limitation to ongoing penetrating keratoplasty.

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.

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.

Indications for Penetrating Keratoplasty in North China

PURPOSE

To analyze leading indications for penetrating keratoplasty (PKP) in north China and changing trends in them.

METHODS

We retrospectively reviewed the records of patients who underwent PKP at Shandong Eye Institute from January 1997 to December 2002. Infectious keratitis (fungal, bacterial, and acanthamoeba), herpes simplex keratitis (HSK), corneal scarring, keratoconus, bullous keratopathy, regrafting, corneal dystrophy and degeneration, and others were included in the indications for PKP. Initial diagnoses and causes of regrafting were recorded, as well as the related intraocular surgeries for bullous keratopathy.

RESULTS

A total of 1702 patients (1702 eyes) were included in this study. The leading indications for PKP were infectious keratitis (31%), followed by HSK (18%), corneal scarring (16%), keratoconus (13%), bullous keratopathy (7%), regrafting (5%), and corneal dystrophy and degeneration (4%). Percentage of PKP for keratoconus and bullous keratopathy increased significantly during the 6 years, contrary to HSK and corneal scarring. Fungal infections accounted for 66% of infectious keratitis. Of 118 bullous keratopathy cases, 90 (76%) were associated with cataract surgery. The leading initial diagnoses of regrafting were corneal burns (25%), HSK (23%), and infectious keratitis (14%); the major causes included immune rejection (61%), graft infection (14%), and recurrence of HSK (10%).

CONCLUSIONS

Infectious keratitis remains the most common indication for PKP in north China. Moreover, there is an increasing trend in the percentage of PKP for keratoconus and bullous keratopathy.

Activité de greffe de cornée en France (1990-2005) : vers une stabilisation de la demande et de l’offre

OBJECTIVE

To evaluate changes in the balance between supply and demand for corneal grafts over the last 15 years in France in the light of the measures implemented and the 2005 national and regional audit.

MATERIALS AND METHODS

Corneal transplantation activities were estimated, mainly from a national prospective survey of ophthalmologists (1991-1994), annual surveys of ophthalmologists (1995-2000), tissue banks (1996-2005), and the national waiting list for surgery (since 2000).

RESULTS

In 2005, the main indicators available were consistent with a stabilization in the number of candidates added to the waiting list every year (4606 in 2005), accompanied by a large increase in the number of grafts procured (9264 in 2005). There was also a substantial increase in quality testing of these grafts, leading to a high rate of rejection (49.5% of the procured grafts). In addition, the number of grafts exported decreased to a very low level (213 in 2005). The percentage of malades registered on the waiting list who received grafts in the same year also increased (68.5% in 2005). Once the waiting list had been updated, 3016 malades remained on the list at the beginning of July 2006. The gap between supply and demand for corneal transplantation has therefore narrowed. Two actions made particularly large contributions to these changes: the creation in 2000 of 120 full-time staff positions in hospital coordination teams, which has had a major impact on procurement rates; and the organization of the tissue bank sector, making it possible to guarantee the quality and distribution of grafts.

CONCLUSION

Corneal procurement and transplantation activities seem to have reached equilibrium in France. A reliable estimation of demand, particularly at the regional level, has led the French agency in charge of tissue transplantation to modify the functioning of the national corneal transplant waiting list, with tissue banks now allowed access to declare transfers and the temporary registration of malades on the list to limit stagnation.

National Survey on Bullous Keratopathy in Japan

PURPOSE

To present the results of a national survey on bullous keratopathy (BK) in Japan.

METHODS

A cross-sectional national survey was conducted for 963 eyes with BK seen between 1999 and 2001 by members of the Japan Cornea Society. Demographic characteristics, type of surgery, complications, and postoperative outcome were analyzed.

RESULTS

BK accounted for 24.2% (963 eyes) of total keratoplasties performed during the period. Graft clarity was maintained in 77.4% of cases, and immunologic rejection and elevated intraocular pressure was noted in 10.8% and 15.3%, respectively. Cataract surgery was the most common cause of BK (n = 428, 44.4%), and phacoemulsification and aspiration were performed in approximately 40% of cases. BK secondary to laser iridotomy (LI) was the second most common cause of BK (n = 225, 23.4%). LI was performed as a prophylactic measure in approximately one half of these cases. BK developed with a mean duration of 6.8 years after LI. Fuchs dystrophy was the cause of BK in 18 eyes (1.9%).

CONCLUSIONS

The causes of BK in Japan are considerably different from those in other Western countries. LI-related BKs showed a remarkably high number, whereas Fuchs dystrophy was observed only rarely.

Baseline factors predictive of incident penetrating keratoplasty in keratoconus

PURPOSE

To identify baseline demographic and clinical factors associated with undergoing penetrating keratoplasty (PK) in a prospective cohort of 1,065 keratoconus patients followed for eight years in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study.

DESIGN

Multicenter, prospective, observational cohort study.

METHODS

We report the rate of PK over eight years and baseline factors predictive of PK in 1,065 patients who, at the time of study enrollment, had not undergone PK in either eye.

RESULTS

Eighty-two percent of patients completed the eight-year close-out visit. Twelve percent (126 of 1,065) had PK in one (9.3%) or both eyes (2.5%). Baseline factors associated with increased likelihood of PK included younger age, steeper keratometric values, worse visual acuity, corneal scarring, poorer contact lens comfort, and poorer vision-related quality of life. The percent of eyes undergoing PK was 15% for patients 40 years old and younger, 28% for eyes with a steep keratometric value greater than 52 diopters, 33% for visual acuity less than 20/40, and 24% for eyes with corneal scarring.

CONCLUSIONS

The CLEK Study confirmed previous reports of the increased likelihood of PK associated with corneal scarring, steeper keratometry values, poorer visual acuity, and poorer contact lens comfort. The CLEK Study is among the first to report an increased risk of PK associated with younger age, worse vision-related quality of life, and flatter contact lens fits. Knowledge of these factors is beneficial to clinicians in patient education and may be useful in disease management.

Impact of new lamellar techniques of keratoplasty on eye bank activity

BACKGROUND

Deep anterior lamellar keratoplasty (DALK) has become an increasingly popular alternative to penetrating keratoplasty in patients with stromal corneal pathologies. The main advantages of DALK are: prevention of long-term endothelial loss, elimination of allograft reaction and short topical steroid treatment with lower risks of glaucoma, cataract and infection. Because this technique enables surgeons to use corneal grafts with low endothelial density, the aim of this paper was to determine whether this type of innovation has had a significant impact on eye bank activity.

METHODS

We reviewed our corneal graft activity over a 40-month period and assessed the proportion of deep lamellar and penetrating keratoplasties. During the same period, we also evaluated our eye bank activity and recorded the utilisation of grafts with endothelium abnormalities, which were only suitable for lamellar techniques.

RESULTS

Deep lamellar keratoplasty represented 29.8% (85 out of 285) of corneal transplantations. Forty-eight percent of all corneas stored at the local eye bank were unsuitable for penetrating keratoplasty; 36.6% of those were not suitable for endothelial deficiencies. Among these, 72.7% were used for DALK and 27.3% were rejected. This permitted a 24.5% increase in corneal grafting activity. In contrast, Descemet's membrane was removed at the time of surgery in 12% of corneas with healthy endothelium, which was used for deep lamellar keratoplasty.

CONCLUSIONS

Deep anterior lamellar keratoplasty development and close collaboration between eye banks and surgeons can induce a significant increase in corneal grafting. This could be a partial solution in countries confronted with corneal graft shortages.

The value of corneal transplantation in reducing blindness

PURPOSE

To analyse the role of keratoplasty in reducing world blindness due to corneal diseases.

METHODS

Review of published literature. We collected and analysed articles published in the English language literature related to the prevalence and causes of blindness in different parts of the world, causes of corneal blindness, and outcome of corneal transplantation for various corneal diseases.

RESULTS

A total of 80% of the world's blind live in developing countries. Retinal diseases are the most important causes of blindness (40-54%) in established economy nations while cataract (44-60%) and corneal diseases (8-25%) are the most common causes of blindness in countries with less developed economies. Keratitis during childhood, trauma, and keratitis during adulthood resulting in a vascularized corneal scar and adherent leucoma are the most frequent causes of corneal blindness in developing countries. Corneal diseases are responsible for 20% of childhood blindness. Nearly 80% of all corneal blindness is avoidable. The outcome of keratoplasty for vascularized corneal scar and adherent leucoma is unsatisfactory, necessitating repeat surgery in a high proportion of these cases. Other barriers for keratoplasty in these nations are suboptimal eye banking, lack of trained human resources, and infrastructure.

CONCLUSIONS

Since the developing world carries most of the load of corneal blindness and the major causes of corneal blindness are corneal scar and active keratitis, development of corneal transplantation services need a comprehensive approach encompassing medical standards in eye banking, training of cornea specialists and eye banking personnel and exposure of ophthalmologists to care of corneal transplants for better follow-up care. However, concerted efforts should be made to develop and implement prevention strategies since most corneal blindness is preventable.

Trends in the indications for penetrating keratoplasty, 1980-2001

PURPOSE

To study the leading indications and changing trends for penetrating keratoplasty (PK) over the past 3 decades.

METHODS

This is a retrospective review of 696 cases of PK. The indications for PKs performed at the Duke University Eye Center during the years 1980-1981, 1990- 1991, and 2000-2001 were tabulated to determine trends over the past 3 decades. The main outcome measures were indications for PK.

RESULTS

During this study, 696 PKs were performed. The leading indications for PK and their respective frequencies during 1980-1981, 1990-1991, and 2000-2001 were failed grafts (10.8%, 19.0%, 27.0%, respectively), pseudophakic bullous keratopathy (PBK)/aphakic bullous keratopathy (ABK) (19.4%, 20.6%, 16.7%, respectively), Fuchs dystrophy (15.6%, 13.0%, 23.8%, respectively), keratoconus (13.4%, 8.2%, 11.8%, respectively), and corneal scar (7.0%, 8.9%, 10.7%, respectively). The number of PKs for failed grafts and Fuchs dystrophy increased over time.

CONCLUSIONS

In this study, failed graft has gradually become the leading indication for PK, whereas most other studies have reported PBK as the leading indication. Unlike many other studies, Fuchs dystrophy was a common indication for PK.

Indications of Penetrating Keratoplasty in Northern India

PURPOSE

To identify the indications for penetrating keratoplasty in northern India.

METHODS

All the eye bank records of penetrating keratoplasties performed during the period from June 1997 to November 2003 at Rajendra Prasad Center for Ophthalmic Sciences were reviewed.

RESULTS

During this period, 2022 penetrating keratoplasties were performed. The leading indications for penetrating keratoplasty were corneal scarring (38.03%) followed by acute infectious keratitis (28.38%), regrafting (11.5%), aphakic bullous keratopathy (7.27%), pseudophakic bullous keratopathy (6.18%), and corneal dystrophy (3.85%). Healed infectious keratitis (19.83%) was the most common subcategory among the eyes with corneal scarring followed by traumatic corneal scars (16.71%). Healed (19.83%) and active keratitis (28.38%) together accounted for the majority of keratoplasties (48.21%). In cataract-related corneal edema (13.45%), aphakic bullous keratopathy (7.27%) was almost as frequent as compared with pseudophakic bullous keratopathy (6.18%).

CONCLUSIONS

Corneal infections either active or healed are the most common indication for keratoplasty in northern India.

Comparative evaluation of efficacy and safety of ophthalmic viscosurgical devices in phacoemulsification [ISRCTN34957881]

Background

Various ophthalmic viscosurgical devices (OVD) are used to perform phacoemulsification and other intraocular surgeries. We performed a study to compare the efficacy and safety of three ophthalmic viscosurgical devices that are routinely used in phacoemulsification.

Methods

Fifty-six patients of immature senile cataract with hard nucleus (grade 3 and 4) who underwent phacoemulsification were included. Depending upon the type of OVD, patients were randomly allocated into three groups; group 1 (n = 19), Viscoat^® was used; group 2 (n = 19), Healon GV^® was used; group 3 (n = 18), Healon 5^® was used. Parameters evaluated were uncorrected and best corrected visual acuity, specular microscopy, intraocular pressure and pachymetry both preoperatively and postoperatively on day 1, 1 week, 1 month and 3 months and development of any complication both intraoperative and postoperative were also noted.

Results

The mean increase in central corneal thickness was 15.17% (group 1); 17.26% (group 2) and 16.21% (group 3) on first postoperative day and was comparable in the three groups. The density of endothelial cells decreased postoperatively (day 1) by 12.54% (group 1), 13.76% (group 2) and 13.06% (group 3) and was comparable. The mean preoperative intraocular pressure in groups 1, 2 and 3 were 13.3 ± 2.0, 14.0 ± 2.2 and 13.2 ± 3.2 mmHg respectively, which changed to 16.0 ± 4.7, 12.2 ± 4.7 and 12.3 ± 4.8 respectively on first postoperative day and the change in intraocular pressure was significantly higher in group 1 (1 vs 2 & 1 vs 3; p = 0.02; oneway ANOVA).

Conclusion

Viscoat^®, Healon GV^® and Healon 5^® give comparable results in terms of efficacy and safety in performing phacoemulsification.

Epidemiology and molecular analysis of herpes simplex keratitis requiring primary penetrating keratoplasty

AIMS

To determine whether herpes simplex keratitis (HSK) has declined as an indication for penetrating keratoplasty (PKP) at the University of California San Francisco (UCSF) over the past 30 years.

METHODS

Records of the Hogan Eye Pathology Laboratory were reviewed to determine the incidence of PKP performed for HSK from 1972 through 2001. Archived corneal tissue with the diagnosis of HSK was evaluated for herpes simplex virus (HSV) DNA by polymerase chain reaction (PCR) based assays.

RESULTS

The number of corneal buttons submitted with the clinical diagnosis of HSK decreased from 1972 to 2001, while the overall number of PKPs performed did not. The percentage of corneal buttons with a clinical diagnosis of HSK that contained detectable HSV DNA did not change over the course of the study period.

CONCLUSION

HSK declined as an indication for PKP from 1972 to 2001 at UCSF. It is unlikely that this decline was the result of improved diagnostic accuracy since detection of HSV DNA in corneal buttons with a clinical diagnosis of HSK was similar at the beginning and end of the study period.

Penetrating keratoplasty: indications over a 10 year period

AIMS

To determine the indications for penetrating keratoplasty (PK) at the Corneoplastic Unit and Eye Bank, UK, a tertiary referral centre, over a 10 year period.

METHODS

Records of all patients who underwent PK at our institution between 1990 and 1999 were reviewed retrospectively. Of the 1096 procedures performed in this period, 784 records were available for evaluation (72%).

RESULTS

Regrafting was the most common indication, accounting for 40.9% of all cases. Keratoconus was the second most common indication (15%), followed by Fuchs' endothelial dystrophy (9.3%), pseudophakic bullous keratopathy (7.6%), and viral keratitis (5.9%), which included both herpes simplex and herpes zoster and showed a statistically significant decreasing trend using regression analysis (p<0.005). Among the regraft subgroup, viral keratitis accounted for 21.2% as the underlying primary diagnosis. The most common cause for graft failure in the regraft subgroup was endothelial failure (41.8%).

CONCLUSION

Regrafting is the leading indication for PK; viral disease-although declining-is the leading primary diagnosis.

Expression of HLA-G in human cornea, an immune-privileged tissue

Human leukocyte antigen (HLA)-G retains the capacity to modulate immune responses, favoring the establishment of tolerance in solid-tissue allotransplants. To better understand the mechanisms that promote corneal allograft survival, we investigated whether HLA-G was an immunoregulatory factor involved in corneal immunology. We therefore sought HLA-G expression in corneal tissues. Corneal transplantation consists in replacing the center of a diseased cornea with normal corneal tissue. Two corneal parts are not used in such surgery: diseased central corneal tissue and peripheral normal cornea. For this study, we used healthy corneas obtained from deceased donors and diseased corneas obtained from patients with pseudophakic bullous keratopathy or keratoconus who had undergone corneal transplantation. Immunohistochemical analysis carried out on the cryopreserved corneas showed a positive immunohistochemical staining with anti-HLA-G, anti-HLA-A, -B, and -C, and anti-HLA class I monoclonal antibodies. Staining was obtained for keratocytes, epithelial cells, and endothelial cells from both healthy and pathologic human corneas, revealing the presence of HLA class I proteins, including HLA-G. HLA-G transcripts were detected in normal cornea by reverse transcriptase-polymerase chain reaction with a classical pattern of alternative splicing. The detection of HLA-G protein in adult corneas leads to the conclusion that this protein may contribute to the maintenance of the privileged immune status of cornea.

Penetrating Keratoplasty in Nepal

PURPOSE

To identify indications and outcomes in a large series of penetrating keratoplasty surgeries performed in Nepal.

METHODS

A retrospective case series of 472 consecutive penetrating keratoplasty surgeries (408 patients) performed at Tilganga Eye Center, Kathmandu, Nepal from June 1994 to September 1999.

RESULTS

Mean recipient age was 39.2 years (+/- 19.7 years). Main indications for PKP were corneal scar (37%), adherent leukoma (35%), perforation or impending perforation (9%), pseudophakic bullous keratopathy (6%), keratoconus (4%), and aphakic bullous keratopathy (3%). Mean duration of follow-up was 27.6 +/- 25.1 months. Sixty-five percent of available grafts were clear at 6 months, and 70% of available grafts were clear at 3 years. Six months postoperatively, 15% of patients had acuity better than 6/18, 37% had acuity between 6/18 and 6/60, and 17.7% had acuity between 6/60 and 3/60. Common causes of graft failure were endothelial failure (43%), increased intraocular pressure (15%), ulcer (14%), and trauma (7%).

CONCLUSIONS

The corneal diseases and indications for transplant surgery in Nepal are different from those in the Western world. Despite these differences, penetrating keratoplasty is a successful and reasonable way to reduce corneal blindness in developing nations.

Prediction of visual outcome after penetrating keratoplasty for pseudophakic corneal edema

OBJECTIVE

To evaluate the ability to predict visual outcome after penetrating keratoplasty (PKP) in patients with pseudophakic corneal edema (PCE) or aphakic corneal edema (ACE) based on preoperative parameters available from the patient history and ocular examination.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Forty-eight patients who underwent 59 PKP procedures for PCE between 1997 and 2000 by two cornea specialists.

METHODS

Medical records were retrospectively analyzed for variables in the history and ocular examination before PKP and visual outcome after PKP. Variables included age, gender, presence of diabetes or cardiovascular disease, method of intraocular lens (IOL) implantation during cataract surgery, vitreous loss during cataract surgery, time between cataract and PKP surgery, and maximal visual acuity reached after cataract surgery. The predictive value of each preoperative variable on post-PKP visual outcome was assessed using both univariate and multiple regression analyses.

MAIN OUTCOME MEASURES

Statistical significance for the predictive value of each preoperative variable on post-PKP visual outcome.

RESULTS

Best-corrected visual acuity (BCVA) of 20/40 or better was achieved in 13 patients (27%). The strongest predictor of this outcome was implantation of a bag-fixated or sulcus-fixated IOL at the time of cataract surgery (P = 0.007; odds ratio, 15.8; 95% confidence interval, 1.2-208). Less significant variables included BCVA after cataract surgery, time between cataract surgery and PKP, and gender.

CONCLUSIONS

In planning and advising patients with pseudophakic or aphakic corneal edema who are candidates for PKP, the method of IOL implantation during the cataract surgery is the single most significant predictor of visual acuity after corneal transplantation. Bag-fixated or sulcus-fixated posterior chamber IOL was associated with a better visual outcome than anterior chamber IOL, scleral-fixated posterior chamber IOL, or aphakia.