Juan Alvarez de Toledo

Causes of intrastromal corneal ring segment explantation: Clinicopathologic correlation analysis

PURPOSE: To determine the main causes of intrastromal corneal ring segment (ICRS) explantation and the relationship with the microscopic findings on the ICRS surface. SETTING: Vissum Corporation–Instituto Oftalmológico de Alicante, Alicante, Spain. METHODS: This study evaluated ICRS that were explanted in centers in Spain from 2000 to 2008. Clinical data (reasons for explantation, date of implantation/explantation, tunnel creation technique, ICRS type) and scanning electron microscopy findings on the ICRS surface (adherent tissue‐like material, cell deposits, protein) were documented. RESULTS: Intrastromal corneal ring segments were explanted from 58 eyes (47 patients). The main cause was extrusion (48.2% of explanted segments), followed by refractive failure (ie, poor refractive outcome) (37.9%), keratitis (6.8%; 3.7% culture positive), and corneal melting and perforation (6.8%). Scanning electron microscopy showed cells and cell debris on the ICRS explanted by extrusion, a clean surface on the ICRS explanted for refractive failure, and bacteria (cocci) in the case of proven infectious keratitis. CONCLUSIONS: The main cause of explantation was extrusion of the ICRS followed by refractive failure. There was a clear correlation between the cause of explantation and the microscopic findings on the ICRS. Extrusion was accompanied by inflammatory cells and cell debris on the ICRS surface. No inflammatory reaction was observed on the ICRS explanted for refractive failure. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

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.

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.

Neural contrast sensitivity calculated from measured total contrast sensitivity and modulation transfer function

Purpose:  To test the feasibility of calculating neural contrast sensitivity function (neural CSF) from conventionally measured total contrast sensitivity function (total CSF) and measured modulation transfer function (MTF). Neural CSF considers the retina and the brain, whereas total CSF considers the optical eye media, the retina and the brain together.

Lisch corneal dystrophy

Purpose: To report a case of a patient with a corneal band-shaped microcystic dystrophy. Methods: Case report. Results: A 70-year-old woman with unilateral painless loss of visual acuity presented an epithelial feathery corneal opacification involving visual axis that showed an intraepithelial dense microcystic pattern. Histopathologic examination of the epithelial scraping revealed scattered areas of vacuolization within almost the entire epithelium. Visual acuity improved after treatment, and no recurrence was observed. Conclusions: Clinical and histopathologic features correspond with those described by Lisch in his original report of 1992.

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.

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 Bowmans layer, the thickness of the stroma and Descemets 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 Descemets 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 Descemets membrane, along with limbal stem cell transplantation, to address epithelial and stromal pathology.

Storage, surgery, outcome, complications, and new developments in corneal and conjunctival grafts.

This review covers last years literature on corneal, limbal, and conjunctival transplantation including tissue storage and eye banking. In this area, the main themes were related to a better evaluation of tissue viability and the exclusion of disease transmission. An analysis of the changing indications for penetrating keratoplasty shows the differences between American and European series. Most efforts in relation to surgical techniques are oriented toward obtaining better refractive results, whereas the study of large series sheds new light on the risk factors for graft failure and other complications. Limbal transplants have acquired the status of a new field in the surgical treatment of ocular surface disease, particularly in relation to corneal stem cell deficiencies.

Acknowledgements to the Referees

www.karger.com/ore Abcouwer, Steven Ajtony, Csilla Aragona, Pasquale Arévalo, J. Fernando Arias, Lluis Augustin, Albert J. Aveleira, Célia A. Balaskas, Konstantinos Barsam, Allon Bi, Hongsheng Bowl, Wadim Bringmann, Andreas Chatziralli, Irini Chowers, Itay Christoforidis, John Costa, Esmeralda Cruchaga, Carlos Davis, Benjamin De Groef, Lies Digiuni, Maurizio Donate-Lopez, Juan Duran, Juan Fernandes, Rosa Fonollosa, Alex Georgiou, Anne Harrison, Ian He, Mingguang Heeren, Tjebo Hjortdal, Jesper Hussain, Ali Jaksic, Vesna Kalogeropoulos, Christos Kanonidou, Evgenia Kondo, Hiroyuki Kroupis, Christos Kühlewein, Laura Kusaka, Shunji Lai, Chi-Chun Lengyel, Imre Martin, Gottfried Martins, João Mathew, Raeba Medeiros, Marco D. Mesquida, Marina Murta, Joaquim Nakahara, Tsutomu Ni Dhubhghaill, Sorcha Noda, Kousuke Panos, Georgios Paques, Michel Parisi, Vincenzo Picaud, Serge A. Pinazo-Duran, Maria Dolores Porciatti, Vittorio Quadrado, Maria João Radach, Ralph Rezende, Flavio Rotenstreich, Ygal Rozema, Jos J. Santiago, Ana Raquel Sappington, Rebecca M. Saxena, Sandeep Schlottmann, Patricio Schmetterer, Leopold Sheha, Hosam Shieh, Chi-Chang Silva, Rufino Stahl, Andreas Stalmans, Peter Stieger, Knut Strong, Stacey Suzuma, Kiyoshi Terasaki, Hiroko Tian, Kailin Toth, Marta Tsubota, Kazuo Vujosevic, Stela Watson, Peter Xu, Heping Yanagi, Yasuo Yang, Sung Jae Zarogiannis, Sotirios

Lamellar and Penetrating Keratoplasty in Congenital Aniridia

Aniridia is a rare panocular disorder affecting the cornea, anterior chamber, iris, lens, retina, macula and optic nerve. It occurs as a result of abnormal neuro-ectodermal development secondary to a mutation in the PAX6 gene, linked to 11p13 chromosome. In this group of patients, one of the causes of progressive loss of vision and morbidity is keratopathy derived from the dysfunction of limbal stem cell deficiency. The absence of this important limbal structure suggests the origin of the epithelial abnormalities involving a progressive corneal opacification, sub-epithelial fibrosis and neovascularization. The management of ocular surface diseases in aniridia is complex but has changed in recent years. The progresses in the understanding of the mechanisms involved in cellular renewal of the cornea have allowed an adequate therapeutic approach of these patients. The current treatments for aniridic keratopathy are to replace the limbal stem cells through kerato-limbal allograft with or without subsequent keratoplasty for visual rehabilitation. Based on our experience, Descemet’s membrane and endothelium complex in aniridic patients with keratopathy, has shown to be normal. For that reason, we propose that patients with advanced aniridic keratopathy could be candidates for deep anterior lamellar keratoplasty associated to limbal allograft instead of penetrating keratoplasty.