Penetrating Keratoplasty in Nepal

Changing indications for and trends of keratoplasty in a tertiary comprehensive hospital in northern part of China from 2002 to 2021: a 20-year review

OBJECTIVE

To investigate indications and surgical procedures of keratoplasty in a tertiary comprehensive hospital in northern part of China over a 20-year period.

METHODS

All patients undergoing keratoplasty between January 1, 2002 to December 31, 2021 in a tertiary comprehensive hospital in northern part of China were retrospectively reviewed. The annual proportion of keratoplasty indications and surgical procedures was recorded and analyzed.

RESULTS

A total of 8266 keratoplasty procedures were included. Leading indications were keratoleukoma (n = 2108, 25.50%), followed by regraft (n = 1453 ,17.58%), corneal endothelial dysfunction (n = 1085, 13.13%), and keratoconus (n = 922,11.15%). A decreasing trend was observed for keratoleukoma (P < 0.01) and an increasing trend for corneal endothelial dysfunction (P < 0.01), regraft (P = 0.012), corneal limbal dermoids (P < 0.01) and congenital corneal opacity (P < 0.01). From 2002 to 2021, the proportion of penetrating keratoplasty (PK) had decreased from 73.95% (2002 to 2006) to 53.49% (2017 to 2021). On contrary, anterior lamellar keratoplasty (ALK) (459-705, 26.05-31.96%, P = 0.034) and endothelial keratoplasty (EK) (0-321, 0.00-14.55%, P < 0.01) became more prevalent from 2002 to 2021. For cases with corneal endothelial dysfunction, EK became the preferred technique (74.72%) in the recent 5 years.

CONCLUSION

Over the past 20 years, keratoleukoma and regraft have been the leading indications for keratoplasty. A noticeable shift in surgical preference from PK to DSAEK and ALK is evident, with key indications for keratoplasty including keratoleukoma, regraft, limbal dermoids, endothelial dysfunction, and keratoconus, respectively.

Eye Donation Counsellor Skill Evaluation Tool (EDC-SET): A step toward improved eye donation counseling

PURPOSE

The expansion of the Hospital Corneal Retrieval Programme (HCRP) and the role of Eye Donation Counsellors (EDCs) have shown promising results in increasing donor cornea availability. To further enhance EDC competency and improve cornea availability for transplantation, the study proposes the Eye Donation Counsellor Skill Evaluation Tool (EDC-SET). Key words: Competency assessment, corneal blindness, Eye Donation Counsellors (EDCs), eye health, Hospital Corneal Retrieval Programme (HCRP), skill evaluation.

METHODS

A competency framework for EDCs and a tool for evaluation of the competency level (EDC-SET) was designed, along with scripts for emulating realistic counselling scenarios. Independent assessors were trained on using EDC-SET and evaluated EDCs participating in role-plays based on the pre-designed scripts. EDCs were briefed a priori on the EDC-SET but not on the role play scripts which were used during evaluation.

RESULTS

We piloted the tool at a tertiary eye hospital, and it was found to capture EDC competency reliably. The study evaluated seven EDCs each assessed by two independent assessors. Conformity, kappa, and intraclass correlation coefficient (ICC) values were calculated to estimate the parameter-wise reliability of the EDC-SET. The results suggest that the scores from both assessors closely matched for most of the parameters, and overall, their ratings showed moderate agreement. The difficulty level of each parameter as assessed by the two assessors was also calculated. It was observed that most participants found "Initiation of the Case" and "Empathy and Emotional Support" challenging. However, "Body Language," "Cultural Awareness," and "Attentiveness to Family Dynamics" were perceived as relatively easy or not difficult by participants.

CONCLUSION

Evaluation of EDCs using EDC-SET revealed the varying competency levels of EDCs and showed agreement on the evaluation between the assessors. Implementing the EDC-SET could help standardise the mapping and measurement of the skill set of EDCs, thereby enhancing their performance and reducing corneal blindness in India.

Disparities in Access to Corneal Tissue in the Developing World

Corneal disease is a leading cause of blindness worldwide. For most blinding corneal conditions, keratoplasty is the only way of restoring sight. Unfortunately, access to corneal transplantation is widely variable, most notably due to the lack of suitable donor material. There exists significant disparity between the developed and developing world when it comes to access to cornea tissue, with supply often inversely proportional to burden of disease. The purpose of this review is to identify the current disparities in supply and demand of corneal donor tissue, understand how to access corneal tissue, and propose solutions that promote equitable care for patients with severe corneal disease.

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.

Mechanical Stability of Cryopreserved Split-Thickness Tectonic Corneal Grafts

PURPOSE

To evaluate the influence of cryopreservation on the pressure-strain relationship of microkeratome dissected anterior stromal grafts (ASGs).

METHODS

Partial thickness ASGs were created from 7 pairs of human corneas and randomized to immediate grafting or grafting after 3 months of cryopreservation at -80°C into a whole globe ex vivo corneal perforation model. High frequency ultrasound speckle tracking was used to calculate the cross-sectional axial and lateral strains in each graft at increasing intraocular pressure (IOP) from 5 to 30 mm Hg. The mean axial and lateral strains were compared between the paired groups.

RESULTS

The mean axial and lateral strains were not significantly different between the cryopreserved and noncryopreserved ASGs. The mean lateral strains at 30 mm Hg in the noncryopreserved and cryopreserved grafts were 2.4% ± 2.1% and 1.4% ± 0.7% (P = 0.294), respectively. The mean axial strains at 30 mm Hg in the noncryopreserved and cryopreserved grafts were -7.8% ± 3.3% and -5.5% ± 3.0% (P = 0.198), respectively. A linear pressure-strain relationship was found for all grafts at physiologic IOP.

CONCLUSIONS

ASGs cryopreserved at -80°C maintain their IOP-strain relationship compared with noncryopreserved ASGs at physiologic pressures, supporting the potential use of cryopreserved human corneal stroma for patch grafting procedures.

Lucia and Beyond: Development of an Affordable Keratoprosthesis

PURPOSE

Severe corneal disease contributes significantly to the global burden of blindness. Corneal allograft surgery remains the most commonly used treatment, but does not succeed long term in every patient, and the odds of success fall with each repeated graft. The Boston keratoprosthesis type I has emerged as an alternative to repeat corneal allograft. However, cost limits its use in resource-poor settings, where most corneal blind individuals reside.

METHODS

All aspects of the Boston keratoprosthesis design process were examined to determine areas of potential modification and simplification, with dual goals to reduce cost and improve the cosmetic appearance of the device in situ.

RESULTS

Minor modifications in component design simplified keratoprosthesis manufacturing. Proportional machinist time could be further reduced by adopting a single axial length for aphakic eyes, and a single back plate diameter. The cosmetic appearance was improved by changing the shape of the back plate holes from round to radial, with a petaloid appearance, and by anodization of back plate titanium to impute a more natural color.

CONCLUSIONS

We have developed a modified Boston keratoprosthesis type I, which we call the "Lucia." The Lucia retains the 2 piece design and ease of assembly of the predicate device, but would allow for manufacturing at a reduced cost. Its appearance should prove more acceptable to implanted patients. Successful keratoprosthesis outcomes require daily medications for the life of the patient and rigorous, frequent, postoperative care. Effective implementation of the device in resource-poor settings will require further innovations in eye care delivery.

Etiology of Global Corneal Blindness and Current Practices of Corneal Transplantation: A Focused Review

PURPOSE

The purpose of this focused review was to explore the etiologies of corneal blindness worldwide and compare them with the indications and type of keratoplasties (eg, full-thickness penetrating keratoplasty, anterior lamellar keratoplasty, or endothelial keratoplasty) performed.

METHODS

A literature search of the articles published in the top 10 journals (based on the Altmetrics score) relevant to corneal transplantation within the past 20 years was performed to determine how the focus within corneal transplantation has changed over time. These data were compared with the prevalence and etiology of corneal blindness in each respective region worldwide.

RESULTS

The leading etiologies of corneal blindness worldwide are primarily due to anterior corneal pathology with a normal endothelium, and the prevalence is highest in developing countries. In addition, the number and type of corneal transplantations performed globally indicate that current practices are disproportionately skewed in favor of endothelial keratoplasty, which is targeted for the pathology prevalent in developed countries. Despite the large number of individuals who would benefit from anterior lamellar keratoplasty, this technique seems to be infrequently performed.

CONCLUSIONS

Most corneal blindness worldwide is secondary to anterior corneal pathology because of infections and trauma. However, this does not align with the current trends and practices in the field of corneal transplantation. We discuss potential solutions to address the current leading causes of global corneal blindness, including increasing the number of anterior lamellar keratoplasties performed, using long-term preserved corneas by trained surgeons, and improving eye bank handling and distribution of procured tissues.

Penetrating Keratoplasty at a Tertiary Referral Center in Ethiopia: Indications and Outcomes

PURPOSE

To describe the indications, visual acuity outcomes, and graft survival after penetrating keratoplasty (PKP) in Addis Ababa, Ethiopia.

METHODS

The medical records of patients who underwent PKP at Menelik II Hospital between September 2000 and September 2013 were retrospectively reviewed. The prespecified outcomes were graft survival, visual acuity, and complication rates.

RESULTS

A total of 321 patients underwent PKP during the study period and were included in the analysis. Indications for surgery were trachoma or leukoma in 141 (44%), keratoconus in 45 (14%), corneal dystrophy in 46 (14%), pseudophakic or aphakic bullous keratopathy in 28 (9%), trauma in 27 (8%), previous graft failure in 18 (6%), active ulcer, burn, or perforation in 9 (3%), and others in 7 (2%). The graft survival rate was 80% overall at 2 years but varied considerably depending on the indication for surgery. Uncorrected visual acuity improved from baseline mean logarithm of the minimum angle of resolution 2.09 (SD 0.67) to mean logarithm of the minimum angle of resolution of 1.53 (SD 1.03) at 2 years. A number of factors affected the visual acuity outcomes. Patients were not routinely refracted, and only 18% (N = 60) of patients had access to corrective spectacles or contact lenses postoperatively. Complication rates were high with infectious keratitis being the most common.

CONCLUSIONS

PKP is becoming a viable treatment for corneal opacity in developing countries. However, the high burden of disease and lack of corrective lenses remain significant obstacles to overcome.

Use of glycerol-preserved corneas for corneal transplants

Purpose:

This study was carried out to see the results of glycerol-preserved cornea (GPC) in emergency situation when fresh corneal tissue was not available. The aim was to study the outcome of corneal transplantation using GPC.

Methods:

This was a retrospective study. The medical records of all the patients were reviewed, who underwent keratoplasty using “GPC” during the period from October 2011 to December 2015. The indication of keratoplasty, duration of preservation of the GPC, and its outcome were analyzed. Descriptive statistics were applied.

Results:

Out of the 222 penetrating keratoplasty (PKP) performed over the study period, the GPC was used in 34 patients (males = 31, 91.2%) aged 15–74 years. Therapeutic keratoplasty was performed in all cases in this cohort except one in which tectonic keratoplasty was done. The primary indication of PKP (91.2%) was infectious keratitis. Of these, 20 (64.5%) patients presented with perforated corneal ulcers. Post-PKP, ocular anatomy was preserved in 91.2%, and visual acuity of perception of light positive and accurate projection of rays in all the quadrants was obtained in 76.5% cases. Complications included glaucoma (n = 12, 35.1%), phthisis bulbi (n = 2, 5.9%), and graft reinfection and endophthalmitis after PKP (n = 1, 2.9%). The secondary procedure post-GPC and PKP were trabeculectomy with mitomycin C (n = 7, 58.3%) in patients not controlled on topical antiglaucoma medication. Optical keratoplasty was performed in (n = 3) 8.8% patients and triple procedure in (n = 2) 5.8% patients with good visual acuity postprocedure.

Conclusions:

Acellular GPCs are useful in emergency keratoplasty to avoid loss of vision and can save the eye.

Corneal transplantation at Tenwek Hospital, Kenya, East Africa: Analysis of outcomes and associated patient socioeconomic characteristics

PURPOSE

To review the graft survival rate, visual outcomes, and patient demographics of primary penetrating keratoplasty performed at Tenwek Hospital, a mission hospital in rural Kenya.

METHODS

A retrospective review was performed of the clinical records of patients who underwent primary penetrating keratoplasty for optical purposes from January 2012 to October 2014. The graft survival rates were constructed using the Kaplan-Meier method, and the effect of clinical and socioeconomic characteristics on time to graft failure were examined using Cox regression models.

RESULTS

118 patients met the inclusion criteria. The most common indication for surgery was keratoconus (66.1%), followed by corneal scar (22.0%). Despite all patients giving a verbal commitment to do so, 40 patients (33.9%) failed to make it to followup one year postoperatively. Graft survival at one year, inclusive of all indications, was 85.8%. Of the different indications, keratoconus had the highest one-year graft survival rate of 89.9%. Compared to the preoperative uncorrected visual acuity, 85.3% achieved an improvement at one year. Compared to patients who had completed college or university, the risk of developing graft failure was 4.7 times higher among patients with less education (P = 0.01).

CONCLUSIONS

Corneal transplantation at Tenwek Hospital can be performed with a reasonable chance of success at one year, particularly in cases of keratoconus and in patients with higher educational backgrounds. Adherence to followup recommendations proves to be a challenge in this patient population. Additional studies of larger patient populations with longer follow up periods in similar settings may be helpful in informing appropriate patient selection and maximizing successful outcomes of corneal transplantation in low-resource settings.

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).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Corneal surgery in the flying eye hospital: characteristics and visual outcome

OBJECTIVE

The Flying Eye Hospital (FEH) of ORBIS International is a capacity-building platform that trains ophthalmologists throughout the developing world on-board a fully functional eye hospital based in an airplane and in the local hospitals of developing countries. Corneal blindness (CB) is the second leading cause of blindness in most developing countries. Treatment of existing global CB requires effective eye banking and surgeons trained in corneal transplant. ORBIS International has programs that addressed both those needs. This study reports the clinical outcome of all keratoplasty training programs of the FEH from January 2010 to December 2014.

METHODS

Surveys were sent to all local ophthalmologists trained on FEH to perform keratoplasty in the relevant time period. The survey included patient demographics, procedure performed, indications for surgery, postoperative steroid regiment, and visual acuity (VA).

RESULTS

Keratoplasty was undertaken in 87 eyes as follows: penetrating keratoplasty (PK) in 66 (75.9% of our population), deep anterior lamellar keratoplasty (DALK) in 6 (6.9%), Descemet's stripping endothelial keratoplasty (DSEK) in 14 (16.1%), and Boston keratoprosthesis (KP) in 1 (1.1%). Corneal clouding was the indication in 83 (95.4%) of patients. Forty-seven (54%) patients returned for long-term care with the mean follow-up (FU) of 32.0 months (range 6-60 months). Thirteen (27.7%) were not using any steroids at last the FU. Eleven (23.4%) patients had signs of graft rejection. Best-corrected VA in meters and feet, respectively, was 6/6 to 6/18 (20/20 to 20/60) in 12 (25.5%) patients, 6/18 to 6/60 (20/60 to 20/200) in 19 (40.4%) patients, 6/60 to 3/60 (20/200 to 20/400) in 4 (8.5%) patients, and less than 3/60 (20/400) in 12 (25.5%) patients.

CONCLUSION

Clinical outcomes delivered by FEH keratoplasty training are acceptable compared to results in the developing world and to some reports of training programs in the developed world, though our study is limited by its retrospective nature and the poor rate of FU.

Corneal Transplantation in the Developing World: Lessons Learned and Meeting the Challenge

PURPOSE

To describe the current state of corneal blindness (CB) and corneal transplantation in the developing world.

METHODS

Information on corneal transplantation was obtained from published articles, direct communication with corneal specialists in developing countries, data sourced from eye banks in the United States and abroad, and personal experience.

RESULTS

CB is the fourth leading cause of global blindness. Most of those with CB live in India and Africa. Many developing countries lack sustainable eye banks, and there is a shortage of corneal transplant surgeons. India has started programs to address both these issues, whereas Africa seems the least prepared. Brazil and the Philippines have also made significant progress in eye banking. In addition, studies indicate a role for the use of a keratoprosthesis in select settings. Several international organizations and academic centers have targeted these system-wide deficiencies.

CONCLUSIONS

There are an unacceptable number of people with cornea blindness in the developing world. Programs have been initiated to address eye bank sustainability and to increase surgeon capacity. However, much more work and effort will be needed to improve the current statistics.

Age distribution of various corneal diseases in China by histopathological examination of 3112 surgical specimens

PURPOSE

To analyze the age distribution of corneal disease in China by histopathological examination.

METHODS

A retrospective histopathological analysis of the prevalence and age distribution of corneal disease was performed on corneal specimens from 3112 patients who underwent corneal surgery between 2001 and 2012 in the Henan Eye Institute.

RESULTS

Infectious keratitis (2212 specimens, 71.08%) was the most common corneal disease. The distribution of age groups was significantly higher after age 30 (16.29%), reaching a peak by age 40 (22.04%) and remaining high until age 59 (21.05%, P < 0.01). The highest age-specific percentage of corneal infection was between the ages of 50 and 59 (83.21%, P < 0.01). Noninfectious corneal diseases occurred mainly in the age range of 10 to 19 years (42.47%) and 20 to 29 years (40.78%). Between the ages of 10 and 19, the leading pathologic diagnosis was keratoconus, accounting for 21.29% of cases. In patients aged 80 and older, the most common noninfectious corneal diseases were Terrien-marginal degeneration (8.33%) and Mooren's ulcer (4.17%). The highest incidence of corneal tumor was seen between the ages of 0 and 9 years (65.83%) and age 80 and older (45.86%; P < 0.01).

CONCLUSIONS

The age distribution of corneal diseases in the Chinese population is distinct from other countries. The corneal diseases tend to increase in prevalence in middle age, especially for infectious corneal disease. The prevalence of corneal tumor is high in early and late life. Corneal degenerative disease occurs predominately in seniors.

Corneal blindness and xenotransplantation

Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

Turning the tide of corneal blindness

Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world's largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

Outcome of optical penetrating keratoplasties at a tertiary care eye institute in Western India

Aim:

To study the indications, risk factors, postoperative course, and long-term survival of corneal transplants done for optical purposes.

Design:

Retrospective case series.

Materials and Methods:

Data were obtained by reviewing the records of 181 patients operated at our institute (H.V. Desai Eye Hospital) between October 2005 and October 2007 for optical penetrating keratoplasty. Patients with less than one year of follow up, pediatric cases, therapeutic, tectonic, and lamellar keratoplasties were excluded. Kaplan Meier survival analysis was used to calculate median survival time of grafts and to see correlation between nine variables viz. age, gender, corneal vascularization, previous failed grafts, previous Herpes Simplex keratitis, post-perforation corneal scars, donor tissue quality, graft size, type of surgery and follow-up. These variables were also used for univariate and multivariate analysis using Cox Proportional Hazard Regression Modeling.

Results:

Median survival of the cohort was 27 months (95% confidence interval: 20.47-33.52). One- and two-year survival rates were 65% and 52.5%, respectively. Median survival was significantly lower in poor prognosis cases (14 months) than good prognosis cases (27 months, P = 0.0405). Graft survival was lower in vascularized corneas (18.55 months, P = 0.030) and in post-perforation corneal scars (17.96 months, P = 0.09, borderline significance). Multivariate analysis showed that the same factors were predictive of graft failure.

Conclusion:

Long-term survival of grafts at our center is different from centers in western world. More high-risk cases, paucity of excellent quality donor corneas, and differences in patient profile could be the contributory factors.

The use of glycerol-preserved corneas in the developing world

Corneal opacity is the third leading cause of blindness in the developing world and encompasses a wide variety of infectious, inflammatory and degenerative eye diseases. Most caes of corneal blindness are treatable with partial or full-thickness keratoplasty, provided adequate corneal tissue and surgical skill is available. However, access to sightrestoring keratoplasty in developing countries is limited by the lack of developed eye banking networks and a critical shortage of tissue suitable for transplantation. Beyond the developed world, corneal transplantation using fresh corneal tissue (FCT) is further hindered by unreliable storage and transportation facilities, unorganized distribution networks, the cost-prohibitive nature of imported tissue, unreliable compliance with medications and follow-up instructions and inadequate health and education services. Glycerol-preserved corneas overcome many of these limitations inherent to the use of FCT. As surgical innovation in lamellar corneal surgery expands the potential use of acellular corneal tissue, long-term preservation techniques are being revisited as a way to increase availability of corneal tissue to corneal surgeons throughout the developing world. Herein, we discuss the advantages of using and the applications for glycerol-preserved corneal tissue throughout the developing world.

Cost-effectiveness of the Boston keratoprosthesis

PURPOSE

To conduct a cost-utility analysis and determine the cost-effectiveness of the Boston Keratoprosthesis (Boston Kpro).

DESIGN

Retrospective cohort study.

METHODS

setting: The Massachusetts Eye and Ear Infirmary corneal service. patients: Inclusion required a minimum 2-year follow-up. Patients with autoimmune diseases and chemical burns were excluded. Eighty-two patients were included with various indications for surgery. intervention: The keratoprosthesis is a collar button-shaped polymethylmethacrylate (PMMA) device consisting of 2 curved plates sandwiched around a corneal donor (allo)graft. The device is assembled intraoperatively and sutured to a patient's eye after removing the diseased cornea.

MAIN OUTCOME MEASURES

Average cost-effectiveness of the keratoprosthesis was determined by cost-utility analysis, using expected-value calculations and time-tradeoff utilities. The comparative effectiveness, or gain in quality-adjusted life years (QALYs), was also sought. Cost-effectiveness was compared to recently published data on penetrating keratoplasty (PK).

RESULTS

A total discounted incremental QALY gain for the Boston Kpro of 0.763 correlated with a conferred QALY gain of 20.3% for the average patient. The average cost-effectiveness of the keratoprosthesis was $16 140 per QALY.

CONCLUSIONS

Comparable to corneal transplantation, with a cost-effectiveness between $12 000 and $16 000 per QALY, the keratoprosthesis can be considered highly cost-effective.

Corneal transplant outcome in the Palestinian territories: a 2-year follow-up study

PURPOSE

To review the 2-year corneal transplant outcome in a cohort of patients from the Palestinian territories transplanted at the St John Eye Hospital in East Jerusalem in 2001-2002.

METHODS

Two-year follow-up data were recorded on the Swedish Corneal Transplant Register for 99 of the 161 patients originally transplanted. Multiple regression analyses (linear and logistic) were carried out to determine the influence of diagnosis, preoperative risk factors, and postoperative complications on graft survival and visual outcome.

RESULTS

The incidence of preoperative risk factors in keratoconus patients was similar to other diagnoses (P=0.4) but they had fewer postoperative complications (39 vs 77%, P<0.001). Graft survival was higher in the keratoconus group (96 vs 49%, P<0.001). Visual outcome was also better with 47% of patients achieving VA >or=0.5 (6/12) whereas 88% of the other patients had VA <or=0.2 (6/30). However, 49% of these other patients did gain at least one Snellen line.

CONCLUSION

Indication had the strongest influence on graft survival and visual outcome. Although the overall results were not so good as in Sweden, the majority of Palestinian patients did show some improvement in vision after corneal transplantation.

Early Postoperative Complications of Deep Lamellar Endothelial Keratoplasty

PURPOSE

To report and discuss the early postoperative complications of deep lamellar endothelial keratoplasty (DLEK).

METHODS

The records of the first 44 patients who underwent DLEK by 1 surgeon were reviewed. Complications occurring between the first day and eighth week after surgery were recorded.

RESULTS

In 6 patients (13.6%), the donor disc was floating in the anterior chamber on the first postoperative day and was repositioned with a 30-gauge needle. Fluid was present between the cornea and the disc in 8 patients (18.2%); in 6 of them, the fluid absorbed spontaneously. In 2 patients, the fluid was aspirated 1 month after surgery, but fibrosis developed in the interface. Two patients (4.5%) had persistent corneal edema. In 1 of them, the edema resolved after 2 months, but the other needed penetrating keratoplasty. One patient (2.3%) developed endothelial graft rejection when steroid treatment was discontinued because of exacerbation of preexisting glaucoma. Ten patients (22.7%) had elevated intraocular pressure (IOP) before surgery. The pressure was controlled with topical medication after surgery in 7 patients, 1 patient (mentioned above) suffered graft rejection, 1 patient underwent repeat trabeculectomy, and 1 patient needed insertion of a glaucoma valve. Three patients (6.8%) who did not have glaucoma before surgery developed elevated IOP postoperatively, which was controlled with topical medication.

CONCLUSION

Non-adhesion of the disc and elevated IOP were the most common complications after DLEK. The mechanical preparation of a thinner donor disc and more experience may lead to fewer postoperative complications and their more efficient management.

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.

Penetrating keratoplasty versus intrastromal corneal ring segments to correct bilateral corneal ectasia: Preliminary study

PURPOSE

To describe the outcomes over time in patients with corneal ectasia pathology treated with intrastromal corneal ring segments (Intacs, Addition Technology, Inc.) in 1 eye and penetrating keratoplasty (PKP) in the other eye.

SETTING

Clinica de Cornea, Centro Medico Docente La Trinidad, Caracas, Venezuela.

METHODS

A nonrandomized comparative study and analysis of retrospective data comprised 17 patients who had PKP in 1 eye and Intacs implantation in the other eye. Patients were classified into 2 groups: asymmetric (different grade of keratoconus in each eye) and symmetric (same grade of keratoconus in both eyes). Parameters analyzed included uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and keratometry (flat and steep values and astigmatism readings). Follow-up after PKP was at 24 hours and 6 and 24 months and after Intacs implantation, at 24 hours and 3 and 10 months.

RESULTS

In both groups, UCVA improved and the corneal shape was normal. No patient lost a line of acuity, and BCVA improved in both groups.

CONCLUSIONS

Eyes with Intacs had a shorter recovery time than eyes having PKP. The eyes with Intacs had no complications. Complications in eyes with PKP included cataract, graft rejection, and elevated intraocular pressure. Thus, Intacs segments may delay or prevent the need for a corneal graft, although longer follow-up is needed.

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.