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Visualizing the posterior segment during vitreoretinal surgery can be difficult in eyes with concurrent corneal opacity. Temporary keratoprostheses have emerged as devices that ensure visibility of the posterior vitreous cavity while simultaneously preserving the donor corneal graft. Several models of these devices are described in the current literature, and new design models and surgical techniques surrounding their use continue to be developed. We summarize the different temporary keratoprosthesis models with their associated surgical techniques, advantages, and shortcomings; discuss the clinical results of studies utilizing these devices; and examine alternative tools and techniques for approaching combined anterior and posterior segment operations., (Published by Elsevier Inc.)

Purpose: Keratoplasty patients require regular and timely follow-ups. During this COVID-19 pandemic which restricted global travel, we developed a novel real-time, hybrid teleophthalmology approach to comanage international keratoplasty patients between Singapore and Indonesia., Methods: A retrospective consecutive observational study of 72 corneal patients (63 were postkeratoplasty) who attended a virtual corneal clinic (VCC) between June 2020 and April 2021 at JEC Eye Hospitals (JEC) in Jakarta, Indonesia. ZOOM Meeting software (Zoom Video Communication Inc, San Jose, CA) was used to simultaneously connect the Singapore corneal specialist at Eye & Cornea Surgeons (ECS), Singapore, using a real-time approach. Clinical examinations included full panels of video-linked corneal, glaucoma, and retinal imaging and investigations performed before real-time video-linked slit-lamp examination, with immediate clinical decision making between corneal specialists and patients., Results: VCC enabled effective real-time clinical evaluation and collaborative clinical decisions, with full patient interaction, with the aim of maintenance of graft clarity, visual function, and management of comorbidities-a) topical and systemic medications were adjusted in 79.2% of patients; b) further referrals to glaucoma, retinal, and oculoplastic subspecialists were made in 16.6% of cases; c) additional adjunctive surgical procedures were performed at JEC in 6.9% cases; and d) government permission was obtained for 4 patients (5.6%) to fly to Singapore for urgent corneal surgery., Conclusions: The virtual corneal clinic is a novel real-time hybrid teleophthalmology approach which is effective in the comanagement of international keratoplasty patients and represents the advances in ophthalmic telemedicine., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Competing Interests: None

Objective: To describe the clinical profile and microbiology trends in patients undergoing therapeutic keratoplasty at a multi-tier ophthalmology hospital network in India., Methods: This cross-sectional hospital-based study included 3147 eyes undergoing therapeutic keratoplasty between Jan 2016 and Dec 2020 (5 years period) as cases. The demographic data, clinical profile and microbiological analysis were collected using an electronic medical record system., Results: Of a total of 13,625 eyes with microbial keratitis(non-viral), 3147 (23.1%) underwent therapeutic keratoplasty during the study duration. Majority of patients were males (68.35%), from a rural geography (49.89%) and in 51-60 years age bracket (23.74%). The mean age of the patients was 50.54 ± 15.83 years. Two-thirds of patients were from lower socio-economic strata (66.63%) with an agrarian background (36.51%). Of the 3,147 eyes, fungus (51.8%) was the most common indication of therapeutic keratoplasty followed by bacteria (16.87%) and parasite (1.27%). No organisms could be identified in about a third (29.33%) of the cases. Between 2016 and 2020, the trend of therapeutic keratoplasties for fungal infections steadily grew (39.9% vs 45.49%) while the bacterial infections showed a steady decline (23.15% vs 11.81%)., Conclusions: Medical cure rate was seen in majority of those with microbial keratitis, and 23.1% eventually required management with therapeutic keratoplasty. Fungal keratitis was the most common indication for therapeutic keratoplasty. Male gender, rural setting, low socio-economic background and agricultural occupation are common risk factors for patients undergoing therapeutic keratoplasty in India., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective: Herpetic keratitis, either due to herpes simplex keratitis (HSK) or herpes zoster ophthalmicus (HZO), can recur after eye surgery.º Prophylaxis is postulated as necessary to avoid it. The objective of this study was to review the scientific evidence on the preventive methods used in the perioperative period in patients previously affected by HSK/HZO., Methods: An exhaustive search was carried out in the PubMed and Web of Science databases to identify relevant articles on prophylaxis and risk of recurrence of HSK/HZO in patients undergoing eye surgery up to 31 December 2019., Results: There is strong evidence that oral prophylaxis should be recommended after penetrating keratoplasty in patients who have previously had HSK/HZO. For other types of surgery, the evidence is less compelling. However, a latent period of inactivity should be considered between disease and oral prophylaxis., Conclusions: Penetrating and lamellar keratoplasty, corneal crosslinking, cataract surgery, and photorefractive and phototherapeutic surgery cause an alteration of the subbasal nerve plexus of the cornea. Due to surgical trauma, as well as the modulation of the ocular immune response caused by steroids applied in the postoperative period, it is possible to induce the reactivation of HSK/HZO, which is common in some cases. Within this article, we discuss the available evidence for HSK/HZO prophylaxis in eye surgery. Further studies are necessary to define the real risk of HSK/HZO recurrence after ocular surgeries, particularly in cataract surgery, and to confirm the efficacy of perioperative prophylaxis with anti-HSK/HZO antivirals., (Copyright © 2022. Published by Elsevier España, S.L.U.)

Coronavirus disease 2019 (COVID-19) is caused by a highly contagious RNA virus termed as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Ophthalmologists are at high-risk due to their proximity and short working distance at the time of slit-lamp examination. Eye care professionals can be caught unaware because conjunctivitis may be one of the first signs of COVID-19 at presentation, even precluding the emergence of additional symptoms such as dry cough and anosmia. Breath and eye shields as well as N95 masks, should be worn while examining patients with fever, breathlessness, or any history of international travel or travel from any hotspot besides maintaining hand hygiene. All elective surgeries need to be deferred. Adults or children with sudden-onset painful or painless visual loss, or sudden-onset squint, or sudden-onset floaters or severe lid oedema need a referral for urgent care. Patients should be told to discontinue contact lens wear if they have any symptoms of COVID-19. Cornea retrieval should be avoided in confirmed cases and suspects, and long-term preservation medium for storage of corneas should be encouraged. Retinal screening is unnecessary for coronavirus patients taking chloroquine or hydroxychloroquine as the probability of toxic damage to the retina is less due to short-duration of drug therapy. Tele-ophthalmology and artificial intelligence should be preferred for increasing doctor-patient interaction., Competing Interests: None

Purpose: To evaluate the cost-effectiveness of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) versus standard DSAEK., Methods: A cost-effectiveness analysis using data from a multicentre randomized clinical trial was performed. The time horizon was 12 months postoperatively. Sixty-four eyes of 64 patients with Fuchs' endothelial dystrophy were included and randomized to UT-DSAEK (n = 33) or DSAEK (n = 31). Relevant resources from healthcare and societal perspectives were included in the cost analysis. Quality-adjusted life years (QALYs) were determined using the Health Utilities Index Mark 3 questionnaire. The main outcome was the incremental cost-effectiveness ratio (ICER; incremental societal costs per QALY)., Results: Societal costs were €9431 (US$11 586) for UT-DSAEK and €9110 (US$11 192) for DSAEK. Quality-adjusted life years (QALYs) were 0.74 in both groups. The ICER indicated inferiority of UT-DSAEK. The cost-effectiveness probability ranged from 37% to 42%, assuming the maximum acceptable ICER ranged from €2500-€80 000 (US$3071-US$98 280) per QALY. Additional analyses were performed omitting one UT-DSAEK patient who required a regraft [ICER €9057 (US$11 127) per QALY, cost-effectiveness probability: 44-62%] and correcting QALYs for an imbalance in baseline utilities [ICER €23 827 (US$29 271) per QALY, cost-effectiveness probability: 36-59%]. Furthermore, the ICER was €2101 (US$2581) per patient with clinical improvement in best spectacle-corrected visual acuity (≥0.2 logMAR) and €3274 (US$4022) per patient with clinical improvement in National Eye Institute Visual Functioning Questionnaire-25 composite score (≥10 points)., Conclusion: The base case analysis favoured DSAEK, since costs of UT-DSAEK were higher while QALYs were comparable. However, additional analyses revealed no preference for UT-DSAEK or DSAEK. Further cost-effectiveness studies are required to reduce uncertainty., (© 2019 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Chemokines are chemotactically active cytokines, which coordinate the distribution of immune cells within the body and also regulate the migration of leukocytes in malignant and inflammatory processes. Chemokines are a heterogeneous group of short-chain proteins that are divided into different subgroups on the basis of their structure. In addition to the chemokines (ligands) various chemokine receptors also exist. The chemokine system is given its complexity by the high redundancy of ligand-receptor interactions: one single ligand can bind to different receptors and a single receptor can interact with different ligands. In terms of receptors, distinct immune cell types have characteristic receptor expression patterns, which can be used for the immunological characterization of leukocytes. Important basic research is currently leading to a better understanding of the chemokine system. The essential importance of the chemokine system in various diseases of the anterior and posterior eye segments is becoming increasingly apparent. The following synopsis explains the individual clinical aspects as well as the underlying scientific work in the context of "chemokines in ophthalmology".

Background The importance of evaluating real-life data is constantly increasing. Currently available computer systems better allow for analyses of data, as more and more data is available in a digital form. Before a project for real-life data analyses is started, technical considerations and staff, legal, and data protection procedures need to be addressed. In this manuscript, experiences made at the University Eye Hospital in Munich will be shared. Materials and Methods Legal requirements, as found in laws and guidelines governing documentation and data privacy, are highlighted. Technical requirements for information technology infrastructure and software are defined. A survey conducted by the German Ophthalmological Society, among German eye hospitals investigating the current state of digitalization, was conducted. Also, staff requirements are outlined. Results A database comprising results of 330,801 patients was set up. It includes all diagnoses, procedures, clinical findings and results from diagnostic devices. This database was approved by the local data protection officer. In less than half of German eye hospitals (n = 21) that participated in the survey (n = 54), a complete electronic documentation is done. Fourteen institutions are completely paper-based, and the remainder of the hospitals used a mixed system. Conclusion In this work, we examined the framework that is required to develop a comprehensive database containing real-life data from clinics. In future, these databases will become increasingly important as more and more innovation are made in decision support systems. The base for this is comprehensive and well-curated databases., Competing Interests: Interessenkonflikt: Die Autoren geben an, dass kein Interessenkonflikt besteht., (Georg Thieme Verlag KG Stuttgart · New York.)

Objective: To investigate changes in the patterns of cumulative surgical experience for ophthalmologists in the UK following the introduction of a new national training scheme., Design: Retrospective review of all surgical training records submitted to the UK Royal College of Ophthalmologists by trainees for the award of Certificate of Completion of Training (CCT) for the period 2009-2015., Setting: Secondary level care, UK., Participants: 539 trainees achieving CCT over the 7-year study period., Interventions: Higher specialist training or ophthalmology specialist training., Outcome Measures: Number of CCT awards by years and procedures performed for cataract surgery, strabismus, corneal grafts, vitreoretinal (VR) procedures, oculoplastics and glaucoma., Results: Cataract surgical experience showed little change with median number performed/performed supervised (P/PS) 592, IQR: 472-738; mean: 631. Similarly, the median number of strabismus (P/PS 34), corneal grafts (assisted, 9) and VR procedures (assisted, 34) appeared constant. There was a trend towards increasing surgical numbers for oculoplastics (median 116) and glaucoma (57). Overall case numbers for ophthalmic specialist training (OST) trainees (7-year training programme) were higher than higher surgical training (HST) trainees (4.5-year programme) with the exception of squint (P/PS), corneal grafts (P/PS) and VR cases (P/PS)., Conclusions: Overall case numbers reported at time of CCT application appear stable or with a marginal trend towards increasing case numbers. HST (4.5-year programme) case numbers do not include those performed before entry to HST, and although case numbers tended to be higher for OST trainees (7-year programme) compared with HST trainees, they were not proportionately so., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Western medicine was first introduced to Taiwan by medical missionaries in the mid-19 th century. Modernization of medicine was systematically transplanted to Taiwan in the Japanese colonial period, and ophthalmology was established third among hospital departments, following internal medicine and surgery. Dr Hidetaka Yamaguchi, an ophthalmologist, was the first head of the Taihoku Hospital, later known as National Taiwan University Hospital (NTUH; Taipei, Taiwan). Ophthalmologists during the colonial period conducted studies on tropical and infectious eye diseases. After World War II, ophthalmologists at NTUH played an important role in medical education, residency training, studies, and teaching. Dr Yan-Fei Yang established the Taiwan Ophthalmological Society in 1960 and instituted its official journal in 1962. Dr Ho-Ming Lin established the Department of Ophthalmology at the Tri-Service General Hospital in the 1950s and the Veterans General Hospital in the 1960s. Taiwan ophthalmologists eradicated trachoma by 1971. Cataract surgery and penetrating keratoplasty were initially performed in the 1960s. Currently, there are about 1600 ophthalmologists in Taiwan conducting an estimated 120,000 cataract surgeries and 600 corneal transplantations annually. Many subspecialty societies have been established recently that serve to educate Taiwanese ophthalmologists and to connect with international ophthalmic societies. Taiwan ophthalmologists continue to contribute to the advancement of ophthalmic knowledge globally., (Copyright © 2016. Published by Elsevier B.V.)

Objective: To assess the impact of a skills course on microsurgical skills acquisition and to investigate the validity of a video-based modified Objective Structured Assessment of Technical Skill (OSATS) assessment tool that has not previously been applied to ophthalmic surgery., Design: Prospective longitudinal cohort study., Participants: Fourteen residents were recruited from 20 attendees at the Moorfields Eye Hospital microsurgical skills course for residents., Methods: Each resident performed a standardized microsurgical task consisting of the placement of a 10-0 nylon corneal suture into a model eye using an operating microscope with standardized equipment in a standardized environment. Objective measurements were made using the Imperial College Surgical Assessment Device (ICSAD). This is a motion-tracking device returning 3 parameters for economy of movement: total path length, time, and number of individual hand movements. A concurrent video recording was made of each task by 2 independent observers who were masked to the time of the recording relative to the course and the identity of the resident. Video footage was marked in accordance with the OSATS video scoring template., Main Outcome Measures: Each resident had motion-tracking analysis performed during corneal suturing before and after the course (total path length, time, and number of individual hand movements), along with concurrent OSATS video scores., Results: Skills improvement after the course was found to be statistically significant for all 3 ICSAD economy of movement parameters: path length, P = 0.001; hand movements, P = 0.012; and time, P = 0.009. Differences in the combined OSATS scores of the 2 raters before and after the course were found to be significant (P = 0.039). Interrater reliability of OSATS scorers was 0.78 (alpha Cronbach). Correlations between the OSATS scores and each of the ICSAD parameters were found to be significant (P<0.001)., Conclusions: A video-based OSATS scoring system has significant correlation with the ICSAD motion-tracking parameters, demonstrating concurrent validity between the 2 assessment tools. These data also demonstrate that surgical skill, as measured by a validated motion-tracking system, is significantly improved after a 1-day microsurgical skills course., Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Objective: To evaluate motion tracking as an aid to a more objective assessment of ophthalmic microsurgical skill., Methods: In a cohort study, 3 groups of differing levels of surgical experience were assessed. The groups included novice surgeons (n = 10) with fewer than 5 previously performed corneal sutures, trainee surgeons (n = 10) with 5 to 100 previously performed corneal sutures, and expert surgeons (n = 10) with more than 100 previously performed corneal sutures. The Imperial College Surgical Assessment Device was used for the objective assessment of surgical dexterity during corneal suturing. Each of the subjects used a 10-0 nylon suture in a 3-1-1 pattern on an artificial eye (Royal College of Ophthalmologists, London, England). The Imperial College Surgical Assessment Device measures 3-dimensional spatial vectors via electromagnetic sensors attached to the surgeon's fingers. The number of movements, path length for the respective movements, and time taken to complete the given task were recorded., Results: Highly statistically significant differences were found between the 3 grades of surgeon experience for time taken (P<.001), number of hand movements (P<.001), and path length of the hand movements (P = .002) to complete the given task., Conclusions: Motion analysis measured by this technology may be useful in the formal surgical training of residents and as an objective quantitative measure of dexterity.

Purpose: To determine the opinions regarding risk factors and practice preferences for corneal graft rejection by members of the Bowman Club (UK) and to compare them with those of members of the Castroviejo Society (USA)., Methods: A questionnaire was sent in 1999 to members of the Bowman Club (UK), who were responsible for two thirds of all corneal grafts undertaken annually. The survey included 8 questions identical to those given to members of the Castroviejo Society (USA) in a survey carried out in 1989., Results: Thirty-six out of 40 surgeons replied. Factors considered by respondents to be high risk for corneal graft rejection were previous corneal graft rejection in the operated eye (97%), significant corneal vessels (97%), and previous herpetic eye disease (94%). The preferred routine preoperative treatment in "high-risk" patients included no treatment (47%), topical corticosteroids (33%), and oral prednisolone (22%). In postoperative "high-risk" patients, 100% of surgeons used topical and 42% used oral corticosteroids. Immune suppression agents were used by 44% of respondents, the majority (92%) using cyclosporine A. In previous herpes simplex patients, 47% of surgeons used oral and 14% used topical antivirals preoperatively, whereas 75% used oral and 47% used topical postoperatively., Conclusion: This study documents the perceived risk factors and management of corneal graft rejection by corneal surgeons in the UK. It showed wide variation in practice preferences, allowing individual surgeons a comparison with peer practice. It highlights the need for greater use of postoperative antiviral prophylaxis in the presence of previous herpetic corneal pathology.

Background: The assessment of patient's quality of life is not only of vital importance for clinical trials of new therapies but also becomes more and more implemented into daily clinical therapeutical decisions., Methods: Different methods for evaluating quality of life are available. A well-known questionnaire for measuring global quality of life is the Short Form 36 (SF 36). However, in ophthalmology more specific instruments for measuring visual quality of life are needed. We review the usefulness of specific questionnaires such as the Visual Function 14 (VF-14) or the National Eye Institute Visual Function Questionnaire (NEI-VFQ) in their application to common ophthalmologic diseases such as cataract, age-related macular degeneration and glaucoma. Studies applying these methods were identified by a search in the Medline database., Results: Several instruments to measure visual life quality in ophthalmologic patients are available. Internal consistency and validity are shown., Conclusions: Evaluating visual quality of life is an important parameter for assessing ophthalmologic diseases and the value of different therapies. It is an important outcome variable in clinical studies. Furthermore, individual visual quality of life should be considered in individual therapeutic decisions and helps to assess the economic effect of current and new therapies.

Shortages in transplantable corneas are common, yet little appears in the medical literature about patterns of tissue donation and factors affecting procurement. We have analyzed data on eye donations and taken measures to improve procurement rates based on our findings. Fifty consecutive Cardiovascular Intensive Care Unit (CVICU) deaths were reviewed to compare the number of transplant-eligible donors to the amount of tissue received. An anonymous survey of 250 house staff and nurses was undertaken to identify obstacles to donor eye procurement. Although 12 of 50 potential donors in the CVICU met transplant eligibility criteria, only 1 became a donor. A required request policy notwithstanding, the most common reason for nonprocurement was failure to make a request. According to the survey, the most significant impediments to making the request were (a) not thinking to ask, (b) unfamiliarity with eligibility criteria, (c) unfamiliarity with enucleation procedures, (d) feeling that someone else should make the request, and (e) reluctance to impose on a grieving family. Very few cited religious reasons or being too busy. Education based on the specific concerns listed in the survey was undertaken. During the 12 months after this initiative, the number of transplantable corneas donated from our facility doubled, as compared with the same period in 1992. Despite required request laws and regulations, failure to request tissue donation is common in our facility and may be common elsewhere. Systematic analysis of obstacles to donor eye procurement and their solutions may help to improve our country's performance in this area.

Keratometry provides useful information about the cornea's image-forming properties, such as corneal astigmatism, but is inaccurate on irregular corneas. Quantitative corneal topographic information is now obtainable on irregular corneas, but is difficult for the clinician to interpret. We developed a method to determine the spherical power, astigmatism, and topographic irregularity of a cornea by finding the best-fit spherocylinder that was closest to its measured topography. Keratometric measurements and two videokeratographs were gathered prospectively on 262 normal and abnormal corneas. The best-fit measurements of spherical power, astigmatism, and topographic irregularity were reproducible with one standard deviation of 0.75 diopter or better; agreement with keratometric measurements in normal eyes was good (0.60 diopter or better). Topographic irregularity averaged 0.1 diopter on precision spheres, 0.4 diopter on 146 normal eyes, 0.8 diopter on 29 eyes after radial keratotomy, 2.0 diopters on 58 eyes after penetrating keratoplasty, and 3.0 diopters on 29 eyes with advanced keratoconus. We conclude the following: basic corneal image-forming properties can be measured from videokeratographs; the properties can be determined, by our methods, on irregular corneas in which keratometry is unreliable; and topographic irregularity provides a measure of irregular astigmatism.

Background: Microkeratome designs for lamellar refractive surgery have changed significantly in recent years. Three microkeratome systems (Automatic Corneal Shaper (Steinway Instrument Company, Inc, San Diego, Calif), Draeger Lamellar Keratome (Storz Instrument GmbH, Heidelberg, Germany), and Microprecision test model (Microprecision Instrument Company, Inc, Phoenix, Ariz) were subjected to a concurrent and independent evaluation., Methods: Three types of keratectomies (primary superficial stromal, secondary intrastromal, and primary deep stromal) were performed under identical conditions in human cadaver eyes. The resected discs and the beds were observed for uniformity, accuracy, centering, and smoothness. Scanning electron microscopy of the corneal beds and cutting blades was done., Results: The three systems produced irregular surfaces with chatter lines that appeared least rough with the Draeger rotating machine. The average primary and secondary section diameters were undersized by 10% in all three systems. The average primary keratectomy thickness was more accurate with Steinway, but the variability was over 20 microns in all three systems. Regarding the average secondary keratectomy thickness, Steinway tended to cut thicker, whereas Draeger and Microprecision tended to cut thinner than attempted. The Draeger blade presented the smoothest edge., Conclusions: All three systems need substantial improvements to produce more accurate, reproducible, and smooth resections. More reliable methods to accurately measure the thickness of the resected cornea should be developed.

The Troutman microsurgical keratometer has been shown to be useful in monitoring intraoperative procedures, and it has been demonstrated in the case of cataract and keratoplasty to have a significant influence on the control of operatively induced astigmatism. It is applicable to any surgical procedure which has the potential of altering permanently and unpredictably the corneal curvatures. Intraoperative keratometry has clearly demonstrated some inadequacies of our current cataract and keratoplasty techniques. It is now being used to guide our efforts toward a more rational control of the vexing problem of astigmatism.

Following a brief summary of the optical principles and problems inherent in endothelial specular microscopy, the authors describe the two types of specular microscopes used in the Ophthalmological Department of the University Hospital of Besançon. Their advantages and draw-backs are discussed, and a few representative pictures taken with these two instruments presented.

A new corneal trephine has been described which allows the surgeon to see the circumference of the cutting edge, as well as most of the cornea, lens and iris, while looking through the operating microscope. The trephine has a 3-mm cutting ring supported by an open "branding iron" structure.

We performed a retrospective analysis of the clinical and pathologic diagnoses of 497 corneal buttons that had been submitted to the Estelle Doheny Eye Pathology Laboratory, Los Angeles, during the five-year period 1979 through 1983. The leading indications, in order of decreasing frequency, were pseudophakic bullous keratopathy (17.5%), regrafts (15.1%), aphakic bullous keratopathy (10.9%), corneal trauma (9.3%), and Fuchs' endothelial dystrophy (9.1%). The emergence of pseudophakic bullous keratopathy as the most common cause for penetrating keratoplasty correlates well with the dramatic increase in the number of cataract extractions with intraocular lens implantations performed since the mid-1970s. Less frequent indications for penetrating keratoplasty included the following: corneal scars (6%); active ulcerative keratitis (7%); keratoconus (6%); keratitis secondary to virus (5%); non-Fuchs' corneal dystrophies (3%); congenital corneal opacities (3%); interstitial keratitis (2%); and chemical burns (1%).

Replacement of the dysfunctional cornea was an idea originating in the 18th century. The 19th century was a period of intense experimentation with various forms of keratoplasty. This work bore fruits in the early 1900s when the successful penetrating homograft was realized. Since that time, advances in surgical techniques and method of tissue preservation, as well as a greater appreciation of corneal immunobiology, have made keratoplasty a readily available surgical alternative.

As a result of the widespread use of M-K (McCarey-Kaufman) medium preserved corneas, as well as other methods of preserving corneas in a viable state, I developed a corneal holder to facilitate the lamellar dissection of previously excised whole human corneas. Consisting of a moderately heavy base, cutting pedestal, scleral rim-sealing sleeve, and retaining ring, the corneal holder is economically manufactured, simple to use, and easily sterilized. Its weight and construction allow unassisted dissection of a lamellar graft of any size.

The evolutionary history of the modern day keratoplasty technique is filled with numerous attempts to implant all manner of material using very creative surgical techniques. Many different shapes of incisions were tried. Castroviejo introduced a square shaped keratoplasty technique which had considerable success. He also introduced new surgical instruments which made the procedure easier to perform. This technique remained popular until the 1950s when improved instrumentation along with the demand for the most cosmetically pleasing result displaced the square keratoplasty technique as the keratoplasty procedure of choice.