Keratoprosthesis in dry eye disease.

Bilateral corneal blindness with severe dry eye disease (DED), total limbal stem cell deficiency with underlying corneal stromal scarring and vascularization, combined with adnexal complications secondary to chronic cicatrizing conjunctivitis is a highly complex situation to treat. In such eyes, procedures such as penetrating keratoplasty alone or combined with limbal stem cell transplantation are doomed to fail. In these eyes, keratoprosthesis (Kpro) or an artificial cornea is the most viable option, eliminating corneal blindness even in eyes with autoimmune disorders such as Stevens-Johnson syndrome, ocular mucous membrane pemphigoid, Sjogren's syndrome, and nonautoimmune disorders such as chemical/thermal ocular burns, all of which are complex pathologies. Performing a Kpro in these eyes also eliminates the need for systemic immunosuppression and may provide relatively early visual recovery. In such eyes, the donor cornea around the central cylinder of the Kpro needs to be covered with a second layer of protection to avoid desiccation and progressive stromal melt of the underlying cornea, which is a common complication in eyes with severe DED. In this review, we will focus on Kpro designs that have been developed to survive in eyes with the hostile environment of severe DED. Their outcomes in such eyes will be discussed.

Anatomical and functional outcomes of Boston type I keratoprosthesis as primary penetrating corneal procedure in high-risk and non-high-risk cases.

PURPOSE: To analyze the anatomical and functional results of Boston type I keratoprosthesis (B1-KPro) as a primary corneal procedure in high-risk (HR) cases and non-high-risk (NHR) cases. METHODS: In this retrospective interventional case series, all patients who underwent B1-KPro at a single center between January 2006 and March 2021 were reviewed and identified. Cases were classified according to the primary diagnosis. Anatomical failure was considered in the case of prosthesis extrusion or phthisis bulbi. Functional failure was a postoperative corrected distance visual acuity (CDVA) ≥ 1.3 LogMAR (≤ 0.05 decimal) at the end of the follow-up period. RESULTS: Twenty-three eyes were included for analysis. Thirteen eyes were classified as HR and 10 as NHR. The mean age was 46.5 ± 26.5 years (5-84 years) in the HR group and 49.5 ± 26.9 years (2-78 years) in the NHR group. The mean follow-up was 42.0 ± 35.9 months (1.5-118 months) in HR and 44.8 ± 38.8 months (1-107 months) in NHR. Three eyes in the HR and none in the NHR group showed anatomical failure. Functional failure was reported in 5/13 eyes in the HR and 8/10 in the NHR group. Functional cumulative survival probability was 92% and 82% for the HR group at 1 and 2 years, respectively. In the NHR group, it was 27% at both times. No significant differences were found between groups, except for functional survival in the HR group due to better visual potential of the eyes. CONCLUSIONS: B1-KPro as a primary corneal procedure is a valid option for visual rehabilitation in high-risk cases.

The use of topical cyclosporine A 0.05% as treatment for primary alacrimia in Allgrove syndrome.

INTRODUCTION: The purpose is to report a case on the use of cyclosporine A 0.05% for primary alacrimia in Allgrove syndrome or triple A syndrome (alacrimia, achalasia, and adrenal insufficiency). CASE DESCRIPTION: A 37-year-old man with achalasia treated surgically 11 years ago presented with sensation of a foreign body, irritation, and intermittent ocular redness for several years. Ophthalmological examination revealed bulbar hyperemia, Oxford grade 4 corneal staining, anisocoria, and optic atrophy. The patient was initially treated with washing with serum and lubricants. Due to the persistence of symptoms, treatment with cyclosporine A 0.05% was started observing a clinical improvement with a decrease in the symptoms caused by tear deficiency. CONCLUSION: It is important to emphasize the relevance of establishing an early diagnosis through a complete multidisciplinary clinical examination and a study of adrenal function. The treatment of dry eye in these patients is difficult to manage, with topical immunomodulators such as cyclosporine A as a good alternative when lubricants are insufficient. To our knowledge this is the first case of subjective and objective improvement of dry eye using cyclosporine A 0.05% in a case of alacrimia in triple A syndrome. Allgrove syndrome presentation does not always manifest with the classic triad and some symptoms may be not present at the time of diagnosis. Ophthalmologist and pediatrician should consider this syndrome in patients with symptoms as complex as lack of growth, crying without tears, and convulsions.

Long-Term Anatomical and Functional Survival of Boston Type 1 Keratoprosthesis in Congenital Aniridia.

Purpose: To analyze the long-term anatomical survival, functional survival, and complications of Boston type 1 keratoprosthesis (KPro) in the eyes with congenital aniridia-associated keratopathy (AAK). Methods: A retrospective review of 12 eyes with congenital aniridia that underwent a Boston type 1 KPro surgery was conducted. A Kaplan-Meier analysis was performed. Anatomical and functional success criteria were KPro retention and a best corrected visual acuity (BCVA) ≤1.3 LogMAR (≥0.05 decimal) at the end of a follow-up period. Postoperative complications were recorded. Results: The mean preoperative BCVA was 2.1 ± 0.9 (range: 3.8-1) LogMAR, and glaucoma was a comorbidity in all the cases. Five years after the surgery, the overall retention rate was 10/12 (83.3%), and 50% had functional success. Only three (25%) of the 12 cases did not achieve a BCVA ≤1.3 LogMAR. The cumulative probability of anatomical success was 92, 79, and 79% after 1, 5, and 10 years, respectively. The cumulative probability of functional success was 57 and 46% after 1 and 5 years, respectively. The mean anatomical and functional survival time was 10 ± 1.3 (95% IC = 7.5-12.3 years) and 3.8 ± 0.9 years (95% IC = 1.8-5.8 years), respectively. The most common postoperative complication was retroprosthetic membrane (RPM) formation in 8/16 cases (66%). The mean number of complications per case was 2.4 ± 1.8 (0-6). Conclusions: The Boston type 1 KPro is a viable option for patients with AAK with good anatomical and functional long-term results. Glaucoma is an important preoperative condition that affects functional results. Retroprosthetic membrane formation seems to have a higher incidence in this condition.

Prevalence and antibiotic susceptibility of bacteria isolated in patients affected with blepharitis in a tertiary eye centre in Spain.

PURPOSE: To describe which bacteria can be found on lid margins in patients affected with blepharitis, to show their antibiotic susceptibility pattern, and to evaluate the antibiotic resistance trend of coagulase-negative Staphylococcus through time. MATERIALS AND METHODS: Consecutive cases of 198 eyes affected with blepharitis between 2012 and 2018 were reviewed. A sample was collected by rubbing a swab against the base of the eyelashes of both the eyes of all patients. The samples were inoculated in blood agar and chocolate agar. The susceptibility of the identified bacteria to common antibiotics was tested. In addition, the antibiotic susceptibility pattern of coagulase-negative Staphylococcus detected from year 2016 to 2018 was compared with that of 4 years before. RESULTS: The most common isolated bacterium was coagulase-negative Staphylococcus (89%) and Staphylococcus aureus (28%). Coagulase-negative Staphylococcus showed highest susceptibility to vancomycin (100%), neomycin (94%) and chloramphenicol (91%). Coagulase-negative Staphylococcus and Staphylococcus aureus were the most resistant to penicillin and erythromycin (resistance in 92%, 91% for coagulase-negative Staphylococcus, 86% and 43% of eyes for Staphylococcus aureus). Corynebacterium was resistant to oxacillin and erythromycin. Streptococcus viridans showed resistance to gentamycin and tobramycin. Moraxella was susceptible to most antibiotics. Bacillus was resistant to oxacillin. The antibiotic resistance trend of coagulase-negative Staphylococcus showed that the resistance to rifampicin increased through the years 2012-2018. CONCLUSION: Coagulase-negative Staphylococcus and Staphylococcus aureus were the most isolated bacteria in patients affected by blepharitis in our tertiary eye centre. Both bacteria were resistant to erythromycin. Through the years, it seems that coagulase-negative Staphylococcus gained resistance to penicillin, erythromycin, ciprofloxacin and rifampicin.

Epithelial Ingrowth After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To report the diagnosis, histological findings, and treatment of a patient who developed epithelial ingrowth after Descemet membrane endothelial keratoplasty (DMEK). METHODS: We present the case of a type 2 diabetic 60-year-old man who underwent DMEK for Fuchs dystrophy. Two months after surgery, an epithelial ingrowth in the graft-host interface was suspected. After a 3-month follow-up period in which progressive and centrifugal growth of the epithelial cells in the interface was documented, penetrating keratoplasty (PK) was performed to remove all areas of epithelial ingrowth. No evidence of recurrence was observed 1 year later. RESULTS: Histopathologic evaluation of the corneal button obtained in the PK procedure confirmed the epithelial ingrowth in the interface between the Descemet membrane graft and the host cornea. CONCLUSIONS: Epithelial ingrowth may occur after a corneal endothelium transplant. There have been multiple reports of epithelial ingrowth after Descemet stripping automated endothelial keratoplasty, but this particular case report suggests that epithelial ingrowth may also occur after DMEK. In this case, PK solved the complication.

Osteo-odonto-, Tibial bone and Boston keratoprosthesis in clinically comparable cases of chemical injury and autoimmune disease.

PURPOSE: To compare anatomical and functional results between three types of keratoprosthesis (KPro) in chemical injury and autoimmune disease. METHODS: 70 clinically comparable cases were included as follows: Boston KPro Type 1 25 eyes, osteo-odonto-keratoprosthesis (OOKP) 23 eyes, Tibial bone KPro 22 eyes. Survival times for anatomical and functional success were evaluated with Kaplan-Meier estimations and Log-rank tests. KPro exchange was considered a complication, not as failure. RESULTS: Prosthesis retention in chemical injury group at 5 years was 86% for OOKP, 100% for Tibial bone KPro, and 65% for Boston KPro (p = 0.09), while in the autoimmune disease group it was 66% for Tibial bone KPro and 50% for Boston KPro (p = 0.19; OOKP only one case). Functional success in the chemical injury group at 5 years was 86% for OOKP, 84% for Tibial bone KPro and 71% for Boston KPro (p = 0.38), while in the autoimmune group, it was 44% for Tibial bone KPro and 15% for Boston KPro (p = 0.15; OOKP only one case). The post-operative complications in all groups were: retinal detachment, vitreous hemorrhage, endophthalmitis, retro-prosthetic membrane, uncontrolled glaucoma, the last two being more common in Boston KPro. CONCLUSIONS: For both diagnoses, chemical injury and autoimmune diseases, there was a tendency for better long-term anatomical and functional results with Tibial bone KPro followed by OOKP and Boston KPro Type 1. However, these results were not statistically significant.

Comparison of long-term results between osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

PURPOSE: To compare the anatomical and the functional results between osteo-odonto-keratoprosthesis (OOKP) and keratoprosthesis using tibial bone autograft (Tibial bone KPro). METHODS: We reviewed the charts of 258 patients; 145 had OOKP whereas 113 had Tibial bone KPro implanted. Functional success was defined as best corrected visual acuity ≥0.05 on decimal scale and anatomical success as retention of the keratoprosthesis lamina. Kaplan-Meier survival curves were calculated for anatomical and functional survival as well as to estimate the probability of post-op complications. RESULTS: The anatomical survival for both KPro groups was not significantly different and was estimated as 67% for OOKP and 54% for Tibial bone KPro at 10 years after surgery. There was also no difference found after subdividing for primary diagnosis groups such as chemical injury, thermal burn, trachoma and all autoimmune cases combined. Estimated functional survival at 10 years post-surgery was 49% for OOKP and 25% for Tibial bone KPro, which was significantly different. The probability of patients with Tibial bone KPro developing one or more post-operative complications at 10 years after surgery (65%) was significantly higher than those with OOKP (40%). Mucous membrane necrosis and retroprosthetic membrane formation were more common in Tibial bone KPro than OOKP. CONCLUSION: Both types of autologous biological KPro, OOKP and Tibial bone KPro, had statistically similar rate of keratoprosthesis extrusion. Although functional success rate was significantly higher in OOKP, it may have been influenced by a better visual potential in the patients in this group.

Osteokeratoprosthesis Using Tibial Bone: Surgical Technique and Outcomes.

PURPOSE: To analyze the anatomical and functional results of keratoprosthesis using tibial bone autograft. METHODS: We reviewed 113 charts of patients who underwent tibial bone osteokeratoprothesis implantation at the Centro de Oftalmologia Barraquer. Kaplan-Meier survival curves with 95% confidence interval were calculated for functional success, defined as best corrected visual acuity (BCVA) ≥0.05 on the decimal scale, and for anatomical success, defined as retention of the keratoprosthesis lamina. Multivariate analysis was used to test the impact of clinical factors on anatomical and functional survival rates. RESULTS: Based on Kaplan-Meier analyses, tibial bone keratoprosthesis 5-year and 10-year anatomical survival rates were 69.5% and 53.5%, respectively. Functional survival rate at 5 years was 33% and at 10 years was 19.2%. Considering primary diagnosis, chemical burn had better anatomical and functional survival rates than autoimmune or infectious diseases. Patient age did not have a significant effect on keratoprosthesis survival rates. About 48.7% of the patients who underwent surgery had complications: keratoprosthesis extrusion, glaucoma, retinal detachment and buccal mucosa necrosis were the most frequent ones. CONCLUSION: Half of the patients with tibial bone KPro had retained the keratoprosthesis after 10 years post-surgery and one-fifth of them had visual acuity of 0.05 or better at the same period. Considering that these patients have no other way to recover their vision either because they have no canine tooth or their buccal or dental conditions are not adequate for OOKP, this modified surgery is their only hope.

Histopathology Findings of Corneal Buttons in Congenital Aniridia Patients.

PURPOSE: To evaluate the corneal button of primary penetrating keratoplasty of patients diagnosed with congenital aniridia. The study took place at the Instituto Universitario Barraquer and the Centro de Oftalmología Barraquer. METHODS: A retrospective analysis of cases diagnosed with congenital aniridia was carried out. We analyzed 13 corneal buttons of 11 eyes with congenital aniridia. We only included those patients who underwent penetrating keratoplasty for the first time. The corneal buttons were analyzed for histological characteristics of the presence of vascularization, the presence or not of Bowman's layer, the thickness of the stroma and Descemet's membrane, and endothelium layer alterations. RESULTS: We found alterations in the epithelium and stroma in all patients, although this loss of architecture was not seen in Descemet's membrane and the endothelial population. CONCLUSION: Patients with advanced congenital aniridic keratopathy may be good candidates for deep or superficial anterior lamellar keratoplasty for the preservation of normal endothelium and Descemet's membrane, along with limbal stem cell transplantation, to address epithelial and stromal pathology.

Transcriptome Analysis of Cultured Limbal Epithelial Cells on an Intact Amniotic Membrane following Hypothermic Storage in Optisol-GS.

The aim of the present study was to investigate the molecular mechanisms underlying activation of cell death pathways using genome-wide transcriptional analysis in human limbal epithelial cell (HLEC) cultures following conventional hypothermic storage in Optisol-GS. Three-week HLEC cultures were stored in Optisol-GS for 2, 4, and 7 days at 4 °C. Partek Genomics Suite software v.6.15.0422, (Partec Inc., St. Louis, MO, USA) was used to identify genes that showed significantly different (P < 0.05) levels of expression following hypothermic storage compared to non-stored cell sheets. There were few changes in gene expression after 2 days of storage, but several genes were differently regulated following 4 and 7 days of storage. The histone-coding genes HIST1H3A and HIST4H4 were among the most upregulated genes following 4 and 7 days of hypothermic storage. Bioinformatic analysis suggested that these two genes are involved in a functional network highly associated with cell death, necrosis, and transcription of RNA. HDAC1, encoding histone deacetylase 1, was the most downregulated gene after 7 days of storage. Together with other downregulated genes, it is suggested that HDAC1 is involved in a regulating network significantly associated with cellular function and maintenance, differentiation of cells, and DNA repair. Our data suggest that the upregulated expression of histone-coding genes together with downregulated genes affecting cell differentiation and DNA repair may be responsible for increased cell death following hypothermic storage of cultured HLEC. In summary, our results demonstrated that a higher number of genes changed with increasing storage time. Moreover, in general, larger differences in absolute gene expression values were observed with increasing storage time. Further understanding of these molecular mechanisms is important for optimization of storage technology for limbal epithelial sheets.

Serum-free and xenobiotic-free preservation of cultured human limbal epithelial cells.

AIM/PURPOSE OF THE STUDY: To develop a one-week storage method, without serum and xenobiotics, that would maintain cell viability, morphology, and phenotype of cultured human limbal epithelial sheets. MATERIALS AND METHODS: Human limbal explants were cultured on intact human amniotic membranes for two weeks. The sheets were stored in a hermetically sealed container at 23°C in either a serum-free medium with selected animal serum-derived compounds (Quantum 286) or a xenobiotic-free medium (Minimal Essential Medium) for 4 and 7 days. Stored and non-stored cultures were analyzed for cell viability, amniotic membrane and epithelial sheet thickness, and a panel of immunohistochemical markers for immature cells (ΔNp63α, p63, Bmi-1, C/EBP∂, ABCG2 and K19), differentiated cells (K3 and Cx43), proliferation (PCNA), and apoptosis (Caspase-3). RESULTS: The cell viability of the cultures was 98 ± 1% and remained high after storage. Mean central thickness of non-stored limbal epithelial sheets was 23 ± 3 µm, and no substantial loss of cells was observed after storage. The non-stored epithelial sheets expressed a predominantly immature phenotype with ΔNp63α positivity of more than 3% in 9 of 13 cultures. After storage, the expression of ABCG2 and C/EBP∂ was reduced for the 7 day Quantum 286-storage group; (P = 0.04), and Bmi-1 was reduced after 4 day Quantum 286-storage; (P = 0.02). No other markers varied significantly. The expression of differentiation markers was unrelated to the thickness of the epithelia and amniotic membrane, apart from ABCG2, which correlated negatively with thickness of limbal epithelia (R = -0.69, P = 0.01) and ΔNp63α, which correlated negatively with amniotic membrane thickness (R = -0.59, P = 0.03). CONCLUSION: Limbal epithelial cells cultured from explants on amniotic membrane can be stored at 23°C in both serum-free and xenobiotic-free media, with sustained cell viability, ultrastructure, and ΔNp63α-positivity after both 4 and 7 days.

Influence of primary diagnosis and complications on visual outcome in patients receiving a Boston type 1 keratoprosthesis.

PURPOSE: To analyse how primary diagnosis and complications affect the evolution of post-operative visual acuity (VA). METHODS: We performed retrospective chart analysis on 59 eyes in 57 patients with various diagnoses, most of which were non-standard indications for Boston type 1 keratoprosthesis (Kpro) implantation. The follow-up period was at least 3 months. Patients were classified based on the evolution of post-operative VA: group A demonstrated stable VA improvement, group B lost VA improvement and group C no significant VA improvement. RESULTS: We assigned 46% of our cases to group A with stable VA improvement, 32% to group B with lost VA improvement, and 22% to group C with no VA improvement. The number of graft failures before Kpro implantation did not influence VA outcome. Except for the relatively good VA outcome in chemical burn and radiation injury patients, there seems to be no association between primary diagnosis and positive or negative VA outcome. Only 9% of patients with posterior segment complications and 20% with infections and associated pathologies were assigned to group A. CONCLUSION: Most cases (78%) showed improvement in VA after Boston type 1 Kpro (groups A and B). Posterior segment complications and infections mostly resulted in persistent loss of vision. These complications should be prevented and carefully treated.

Anatomical survival and visual prognosis of Boston type I keratoprosthesis in challenging cases.

PURPOSE: To describe the outcome of patients with Boston type 1 keratoprosthesis, with regard to anatomical and visual success. METHODS: Retrospective case series of patients who underwent Boston type I keratoprosthesis surgery at the Centro de Oftalmología Barraquer in Barcelona and at the University Eye Clinic in Salzburg between May 2006 and December 2011. Sixty-seven eyes were included. Anatomical success, visual acuity, and complication rate were evaluated and correlated with the initial diagnosis. RESULTS: The mean age of patients was 54 years; 62 % were male and 38 % were female. Eleven patients underwent Type I Boston Kpro implantation as a primary procedure, while the other 52 patients had previous graft failure. The most frequent diagnoses were autoimmune diseases (16 eyes), severe chemical or thermal burn (12 eyes), leukoma post-infectious keratitis (seven eyes) and bullous keratopathy (six eyes). The mean follow-up time was 26 months. Retention of the prosthesis was achieved in 95 % at 1 year and 78 % at 4.5 years. Two eyes suffered extrusion of the KPro, six underwent successful exchange of the prosthesis either due to infection, necrosis or extrusion, three KPro's had to be explantated, and two eyes ended up in enucleation due to panophthalmitis. The outcome of the autoimmune cases was similar to the group with "other diagnoses" and better than those with chemical/thermal burn. The most frequent complication was development of a retroprosthetic membrane in 21 eyes (34 %). Visual acuity (LogMAR) in the chemical/thermal burn group was 2.30 preoperatively, 0.69 at 1 year, 0.52 at 2 years and 0.39 at 3 years; in the autoimmune group visual acuity was 2.3 preoperatively, 0.65 at 1 year, 0.15 at 2 years, and 1.5 at 3 years. CONCLUSIONS: Boston type 1 keratoprosthesis is a viable option for patients with repeated graft failure, even for those with challenging diagnoses such as ocular burns and autoimmune syndromes.

A comparison of stem cell-related gene expression in the progenitor-rich limbal epithelium and the differentiating central corneal epithelium.

PURPOSE: Corneal epithelium is maintained by a population of stem cells (SCs) that have not been identified by specific molecular markers. The objective of this study was to find new putative markers for these SCs and to identify associated molecular pathways. METHODS: Real time PCR (rt-PCR) was performed in 24 human limbal and central corneal epithelial samples to evaluate the gene expression profile of known corneal epithelial SC-associated markers. A pool of those samples was further analyzed by a rt-PCR array (RT²-PCR-A) for 84 genes related to the identification, growth, maintenance, and differentiation of SCs. RESULTS: Cells from the corneal epithelium SC niche showed significant expression of ATP-binding cassette sub-family G member 2 (ABCG2) and cytokeratin (KRT)15, KRT14, and KRT5 genes. RT²-PCR-A results indicated an increased or decreased expression in 21 and 24 genes, respectively, in cells from the corneal SC niche compared to cells from the central corneal epithelium. Functional analysis by proprietary software found 4 different associated pathways and a novel network with the highest upregulated genes in the corneal SC niche. This led to the identification of specific molecules, chemokine (C-X-C motif) ligand 12 (CXCL12), islet-1 transcription factor LIM/homeodomain (ISL1), collagen-type II alpha 1 (COL2A), neural cell adhesion molecule 1 (NCAM1), aggrecan (ACAN), forkhead box A2 (FOXA2), Gap junction protein beta 1/connexin 32 (GJB1/Cnx32), and Msh homeobox 1 (MSX1), that could be used to recognize putative corneal epithelial SCs grown in culture and intended for transplantation. Other molecules, NCAM1 and GJB1/Cnx32, potentially could be used to positively purify them, and Par-6 partitioning defective 6 homolog alpha (PARD6A) to negatively purify them. CONCLUSIONS: Knowledge of these gene and molecular pathways has provided a better understanding of the signaling molecular pathways associated with progenitor-rich limbal epithelium. This knowledge potentially could give support to the design and development of innovative therapies with the potential to reverse corneal blindness arising from ocular surface failure.

Impact of clinical factors on the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

PURPOSE: To report the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis; to analyze the influence of clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, on the final outcome. DESIGN: Retrospective cohort study. METHODS: setting: Centro de Oftalmología Barraquer, between 1974 and 2005. PARTICIPANTS: Two hundred twenty-seven patients. intervention: Biological keratoprosthesis using osteo-odonto-keratoprosthesis or tibial bone keratoprosthesis. main outcome measures: Functional survival with success defined as best-corrected visual acuity ≥0.05; anatomic survival with success defined as retention of the keratoprosthesis lamina. RESULTS: Osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis have comparable anatomic survival at 5 and 10 years of follow-up, but osteo-odonto-keratoprosthesis has a significantly better functional success than tibial bone keratoprosthesis at the same time periods. Among the primary diagnoses, Stevens-Johnson syndrome, chemical burn, and trachoma have generally good functional and anatomic outcomes and the least favorable prognosis is for ocular cicatricial pemphigoid. Younger patients fared better than those in older age groups. The most frequent complications were extrusion (28%), retinal detachment (16%), and uncontrolled glaucoma (11%). The glaucoma group had the best anatomic success but the worst functional results, only exceeded by the retinal detachment group in terms of functional outcome. CONCLUSION: Clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, can affect the long-term anatomic and functional successes of biological keratoprosthesis. Knowledge about the impact of each of these factors on survival can help surgeons determine the best approach in every particular case.

Wedge resection for high astigmatism after penetrating keratoplasty for keratoconus: refractive and histopathologic changes.

PURPOSE: To analyze the refractive, topographic, keratometric changes and the histopathologic findings after wedge resection to correct high astigmatism after penetrating keratoplasty for keratoconus. MATERIALS AND METHODS: A retrospective study was done analyzing the following parameters preoperatively and at 1, 3, and 5 years postoperatively: uncorrected visual acuity, best-corrected visual acuity, and spherical equivalent and refractive, topographic, and keratometric cylinder measures. We also studied the efficacy and safety indices, as well as the histopathologic findings of tissues submitted for pathology. RESULTS: A total of 22 eyes of 21 patients who underwent wedge resection in the host corneal tissue for correcting high irregular astigmatism after penetrating keratoplasty for keratoconus were included in the study. Mean follow-up time from penetrating keratoplasty to wedge resection was 18 years, whereas the mean follow-up time after wedge resection was 39.04 months (range, 12-280 months). The mean preoperative refractive, topographic, and keratometric cylinders were 11.58 +/- 3.52 diopters (D) (range, 4.5-20 D), 10.88 +/- 5.03 D (range, 2.58-21.3 D), and 11.29 +/- 4.33 D (range, 4.50-18 D), respectively. The mean postoperative refractive, topographic, and keratometric cylinders at 3 years were 4.91 +/- 2.48 D (range, 0.50-10 D), 3.38 +/- 2.10 D (range, 2.05-7.1 D), and 5.31 +/- 2.90 D (range, 0.50-9 D), respectively. The percentage of correction at 3 years of follow up was 57.5% for refractive cylinder, 68.97% for topographic cylinder, and 53.01% for keratometric cylinder. All refractive, topographic, and keratometric data showed the lowest degree of astigmatism at 3 years postoperatively, with a tendency toward regression at 5 years postoperatively. Safety index was 1.0, whereas efficacy index was 0.49. All histopathologic sections of resected tissue were consistent with keratoconus progression in the host peripheral cornea. CONCLUSION: Wedge resection is a safe and moderately effective procedure in the correction of high astigmatism after penetrating keratoplasty for keratoconus. Histopathologic changes confirm a true late progression of the disease in the host cornea. Keratoconus may be a disease that affects the entire cornea, and surgical resection does not cure the disease.

Topical fusidic acid for treatment of Clostridium perfringens Keratitis.

PURPOSE: To report the therapeutic outcome of primary corneal infection by Clostridium perfringens. METHODS: A 65-year-old cleaning lady had pain, decreased visual acuity, redness, and photophobia in her left eye for 4 days. A paracentral corneal ulcer with subepithelial bullae and several frothy bubbles in the ulcer bed was found. Two different cultures were positive for C. perfringens. RESULTS: Treatment with topical fusidic acid 1% was given, and the corneal infiltrate regressed within 6 weeks to a faint corneal opacity. CONCLUSIONS: Clostridium perfringens keratitis can be treated successfully with topical fusidic acid.

Long-term visual prognosis of corneal and ocular surface surgery in patients with congenital aniridia.

PURPOSE: To evaluate the long-term visual prognosis of corneal and ocular surface surgery in patients with congenital aniridia. METHODS: Retrospective comparative interventional case series on 88 eyes of 45 patients with congenital aniridia treated and/or operated on from 1956 to present. Corneal and ocular surface findings were identified and patients were classified into operated (group I) or not operated (group II). Long-term best-ever best-corrected visual acuity (BCVA), final BCVA and long-term delta BCVA (long-term best-ever BCVA - final BCVA) were recorded and compared between the two groups, and between the limbal transplant (LT) (group I-A) and the penetrating keratoplasty (PK) (group I-B) patients. Postoperative results were also compared. RESULTS: Limbal insufficiency was present in 58% of eyes and dense central corneal opacities were present in 27% of eyes. As a primary surgery, limbal allograft was performed in 10 eyes and PK in 13 eyes. The mean long-term follow-up times were 23 years in group I and 16 years in group II. The mean long-term delta BCVA was 0.032 in group I and 0.028 in group II. Comparisons of the VA means were insignificant (long-term best-ever, final BCVA and long-term delta BCVA). When comparing the LT and PK groups, mean long-term delta BCVA was 0.0328 in group I-A and 0.0382 in group I-B. Mean postoperative delta BCVA was 0.028 in group I-A and 0.048 in group I-B. We found no statistical significance between the LT and the PK groups as regards long-term postoperative BCVA results. CONCLUSION: Long-term visual prognosis does not differ whether or not the patient undergoes surgery for aniridic keratopathy. LT and PK have comparable results over 5 years of follow-up because of the eventual failure of transplanted allografts.

Long-term functional and anatomical results of osteo- and osteoodonto-keratoprosthesis.

PURPOSE: To analyse the functional and anatomical results of keratoprosthesis using tooth and tibial autograft. METHODS: We reviewed 227 charts of patients that underwent osteo-keratoprosthesis (OKP) (n = 82) or osteo-odonto-keratoprosthesis (OOKP) (n = 145) at the Centro de Oftalmología Barraquer. Mean follow-up time was 8.4 years for OOKP and 3.5 years for OKP. Kaplan-Meier survival curves with 95% confidence interval (CI) were calculated for functional success, defined as BCVA >0.05. Anatomical success was defined as retention of the keratoprosthesis lamina. Visual Acuity by Time (VAT) Index with 95% CI was calculated for up to 2 years post-OKP and up to 6 years post-OOKP. Maximum visual acuity ever reached after the last step of the implantation of the keratoprosthesis was used as an indicator for the potential of the retina. RESULTS: Based on Kaplan-Meier analyses, 10-year anatomical survival was 66% (CI 57-76) for OOKP and 47% (CI 27-67) for OKP. Two-year functional survival was 63% (CI 55-71) for OOKP and 49% (CI 37-60) for OKP, and 10-year functional survival was 38% (CI 29-48) for OOKP and 17% (CI 5-28) for OKP. Multivariate analysis showed that neither surgical technique (OOKP or OKP), primary diagnosis nor age had a significant influence on the functional survival. However, a high maximum visual acuity ever reached post-op decreased the risk for functional failure. According to the VAT Index calculations, mean BCVA 2 years after OOKP was 0.33 (CI 0.28-0.41) and after OKP was 0.28 (CI 0.20-0.36). CONCLUSION: Although we found a tendency that OOKP had better anatomical results than OKP, this difference was not statistically significant up to 10 years post-op. Functional results for both techniques were not significantly different at the 2-year follow-up, but at 10 years they were. However, this difference was influenced by the retinal potential and not by the technique itself.