SARS-COV-2 and Ocular Surface: From Physiology to Pathology, a Route to Understand Transmission and Disease.

Coronaviruses gained public attention during the severe acute respiratory syndrome (SARS) outbreak in East Asia in 2003 and spread of Middle Eastern respiratory syndrome (MERS) in 2012. Direct human-to-human contact and droplet are the main methods of transmission. Viral stability in aerosols on different surfaces supports evidence on indirect viral acquisition from fomites through the mucous membranes of the mouth, nose, and eyes. Given the pandemic circumstances, the level of evidence in COVID-19 and ophthalmology regarding eye infection, conjunctival transmission, and viral shedding through tears is insufficient. Presently, conjunctival transmission of coronaviruses has not been confirmed and remains controversial. Considering the physiology of the lacrimal system and ocular surface, the eyes are considered an immunoprotective site, with several antiviral molecules and anti-inflammatory proteins. Nevertheless, they represent an interface with the exterior world and face daily putative aggressors. Understanding the host's ocular surface immunological and protective environment is crucial to clarify the potential of the conjunctiva as an entry route for SARS-CoV-2 and as part of this viral infection. We will discuss hypothetical ocular surface transmission mechanisms and related counterarguments addressed to both angiotensin-converting enzyme 2 receptors found on the conjunctival and corneal epithelia and lactoferrin, lysozyme, lipocalin and secretory IgA levels in the tear film. Hopefully, we will promote better understanding of this organ in COVID-19 infection and the potential transmission route that can be helpful in setting recommendations on best practices and protective guidelines to mitigate the disease spread.

Necrotizing Streptococcus pyogenes Infiltrating Conjunctiva and Tenon's Capsule: A Case Report.

We report a case of a patient with necrotizing infection of the conjunctiva and Tenon's capsule caused by Streptococcus pyogenes, a rare and atypical ophthalmologic condition. A 50-years-old male patient with acute red-eye, purulent discharge, and pain diagnosed with post-septal cellulitis presented with a yellowish and dense membrane covering the ocular surface with necrotic Tenon's capsule. Patient was hospitalized, and intravenous antibiotics were initiated (ceftriaxone and clindamycin). Topical antibiotics and corticosteroids were also administered, and the infection was eradicated in 2 weeks. Ancillary exams excluded rheumatologic involvement. Conjunctival culture confirmed Streptococcus pyogenes growth. Tenon's biopsy revealed unspecific acute inflammatory necrosis. This is an uncommon condition in daily ophthalmological clinic. Literature review reported 3 cases associated with previous ocular surgery.

Standardized pachymetry-assisted manual lamellar dissection for Descemet stripping endothelial keratoplasty.

PURPOSE: To present an alternative technique (Pachy-DSEK) for the manual preparation of thin endothelial lamellae in Descemet stripping endothelial keratoplasty (DSEK), as well as to evaluate its visual and anatomic outcomes. METHODS: A retrospective chart review was conducted in 15 cases who underwent DSEK at a private eye clinic in Brazil (INOB, Brasília) from June 2017 to December 2019. All patients had ocular comorbidities and relative contraindications to Descemet membrane endothelial keratoplasty (DMEK). All endothelial lamellae were manually prepared by using a standardized technique. Best corrected visual acuity (BCVA), tomographic parameters and graft's thickness were evaluated preoperatively and at 6 months. Endothelial cell counts were evaluated preoperatively and at 12 to 24 months. RESULTS: During preparation there was one case (6%) of peripheral tear and no tissue was lost. At 6 months, the median BCVA improved from 1.60 to 0.40 logMAR (p = 0.0009). There was no significant change in anterior (p = 0.507) and posterior astigmatism (p = 0.483), anterior (p = 0.683) and posterior mean keratometry (p = 0.767), and total corneal power (p = 0.952). The median central graft thickness at 6 months was 80 µm. Ultrathin grafts (<130 µm) were achieved in 80% of cases. At 12 to 24 months endothelial cell count decreased significantly. Graft's detachment occurred in two cases (13%) and endothelial rejection in one case (6%). CONCLUSION: By using ultrasonic pachymetry intra-operatively and standardizing graft preparation, most manually dissected endothelial lamellae were ultrathin. Pachy-DSEK was safe and effective for treating endothelial disfunction in eyes with ocular comorbidities. It may be a cost-effective alternative to automated dissection methods.

Visual outcomes in advanced keratoconus using different strategies: Scleral lens, intracorneal ring segment and lamellar keratoplasty.

PURPOSE: To compare VA outcomes in patients with advanced keratoconus wearing SCL or after ICRS or DALK. In addition, determine the percentage of complimentary treatments after ICRS and DALK, and which of these was fitting a SCL, and final visual acuity (f-VA) results. METHODS: Retrospective case series analyzed 55 eyes with advanced keratoconus fitted with SCL, or after ICRS or a DALK between 2010 and 2018. The variables analyzed were sex, age, UDVA, CDVA, SEQ, K-readings, and f-VA after complimentary treatments. RESULTS: Twenty-eight eyes underwent a DALK, 14 were fitted with a SCL, and other 13 underwent ICRS insertion. Patients after DALK and after ICRS showed statistically significant improvement in UDVA and CDVA after surgery, with no difference between these groups. Patients fitted with SCL showed statistically higher CDVA improvement when compared to ICRS. After DALK and ICRS, respectively, nine eyes (32.14%) and seven eyes (53.85%) were fitted with SCL. Comparison between f-VA with SCL in three groups showed that the best result was achieved in DALK + SCL, with statistically significant difference to only SCL. CONCLUSION: We showed that the CDVA of eyes fitted with SCL without any surgical treatment was statistically better than CDVA of eyes after ICRS insertion. After DALK and ICRS insertion, many patients needed a complimentary treatment to improve CDVA. The most chosen treatment was fitting a SCL. After this, all eyes showed statistically significant improvement in f-VA, with statistically better results for DALK + SCL when compared to SCL fitted in advanced keratoconus without any surgical treatment.

Intracorneal Ring Segments Implantation Outcomes Using Two Different Manufacturers' Nomograms for Keratoconus Surgery.

PURPOSE: To compare the outcomes of intracorneal ring segments (ICRS) implantation in keratoconic eyes with a similar tomographic pattern, using two different manufacturers' nomograms for surgical planning. METHODS: ICRS were implanted alternately in patients with the same tomographic pattern of keratoconus divided into two groups according to the surgical planning proposed by the ICRS manufacturers (Keraring, Mediphacos, Belo Horizonte, Brazil, and Ferrara Ring, AJL Ophthalmics, Vitoria, Spain). Visual, refractive, keratometric, corneal aberrometry, and optical quality changes were evaluated during a 6-month follow-up. Corneal and manifest refractive astigmatic changes were also analyzed using the double-angle polar plot and the Alpins vectorial method through the following components: target induced astigmatism, surgically induced astigmatism, difference vector, correction index, angle of error, index of success, flattening effect, and torque. RESULTS: After ICRS implantation, both groups showed significant improvement (P < .05) in visual and keratometric data. Corneal aberrometric changes and optical quality improvement were also statistically significant in both groups, except for trefoil (P > .05 in all intervals). The Alpins method analysis showed a better performance in the Keraring group, but with no statistically significant difference between groups (P > .05). Comparison between groups showed a statistically significant difference only in tomographic astigmatism in double-angle polar plot analysis (P = .03), with more significant improvement in the Keraring group. CONCLUSIONS: Both manufacturers' nomograms resulted in statistically significant improvement in most of the parameters analyzed, with greater correction of corneal tomographic astigmatism in the group operated on according to the spherical equivalent/tomographic astigmatism nomogram. [J Refract Surg. 2019;35(10):673-683.].

The Use of Digital Microscopy to Compare the Thicknesses of Normal Corneas and Ex Vivo Rejected Corneal Grafts with a Focus on the Descemet's Membrane.

OBJECTIVE: To compare the thickness of corneal layers, specifically the Descemet's membrane (DM), in normal corneas and in failed grafts due to rejection (FGRs) using the digital histopathology and to propose a model for the measurement of corneal layers using this method. METHODS: This is a prospective, cross-sectional study performed at the MUHC-McGill University Ocular Pathology & Translational Research Laboratory (McGill University, Montreal, Canada). Histopathological sections of 25 normal human corneas and 40 FGRs were fully digitalized and examined. Inclusion criteria: samples diagnosed as normal corneas or FGRs, from patients older than 18 years of age. Exclusion criteria: histopathological sections without adequate tissue or missing epidemiological information. For each sample, the thicknesses of the epithelium, stroma, and DM were acquired. From a perpendicular plane of reference, two central measurements and two nasal and two temporal peripheral measurements were obtained. RESULTS: There were differences between the normal and FGR groups in the mean central thickness of the epithelium (p < 0.001), the nasal and temporal stromal regions (p < 0.001), and of the DM in the nasal and temporal regions (p < 0.001). Compared with the extremities of the sample (nasal and temporal), the mean thickness of the DM in normal corneas was lower in the central region (p < 0.001), and this difference was not found in the FGR group. CONCLUSIONS: Normal corneas have a thinner epithelium in the central region than the FGR group. In addition, the stroma and DM thicknesses of the nasal and temporal periphery were significantly higher in normal corneas than in those from the FGR group. The digital microscopy protocol applied in this study may be useful for further research studies regarding cornea and other tissues.

Femtosecond laser-assisted deep anterior lamellar keratoplasty in phototherapeutic keratectomy versus the big-bubble technique in keratoconus.

AIM: To compare the functional and anatomic results of femtosecond laser (FSL)-assisted deep anterior lamellar keratoplasty (DALK) associated with phototherapeutic keratectomy (PTK) and FSL-assisted DALK performed using the big-bubble technique in keratoconus. METHODS: During the first phase of the study, an electron microscopy histopathology pilot study was conducted that included four unsuitable donor corneas divided into two groups: in FSL group, FSL lamellar cuts were performed on two corneas and in FSL+PTK group, PTK was performed at the stromal beds of two corneas after FSL lamellar cuts were made. During the second phase of the study, a randomized clinical trial was conducted that included two treatment groups of patients with keratoconus: group 1 (n=14 eyes) underwent FSL-assisted DALK associated with PTK and group 2 (n=12 eyes) underwent FSL-assisted DALK associated with the big-bubble technique. The main outcome measures were the postoperative visual acuity (VA) and optical coherence tomography (OCT) measurements, confocal microscopic findings, and contrast sensitivity. RESULTS: In the pilot study, histopathology showed a more regular stromal bed in the FSL+PTK group. In the clinical trial, group 1 had significantly worse best spectacle-corrected VA and contrast sensitivity (P<0.05 for both comparisons). The residual stromal bed measured by OCT was significantly (P<0.05) thicker in group 1. Confocal microscopy detected opacities only at the donor-receptor interface in group 1. CONCLUSION: Patients with keratoconus treated with FSL-assisted DALK performed using the big-bubble technique fare better than treated with FSL-assisted DALK associated with PTK.

[Corneal transplantation in keratoconus: evaluation of results and complications obtained by skillful and surgeons in training]. / Transplante de córnea em ceratocone: avaliação dos resultados e complicações obtidos por cirurgiões experientes e em treinamento.

PURPOSE: Refractive and visual analysis in corneal transplantations performed for keratoconus by two groups of surgeons. METHODS: Seventy eyes of seventy patients, which had been submitted to penetrating keratoplasty (PK) for keratoconus, were examined and their charts were reviewed retrospectively for long-term results after all sutures had been removed. The patients were divided into two groups, Group I had surgery performed by skillful surgeons and Group II by surgeons in training. The results of best correct visual acuity, refractive error, postoperative complications and computerized videokeratoscopy were compared. RESULTS: The mean follow-up was 7.9 years with a range of 1.6 - 20 years. Each group consisted of 35 eyes. There were 35 females and 35 males. The donor age was different between the two groups. The surgical technique was the same in both groups, but the number of sutures was different. Preoperative mean logMAR visual acuity was low in the two groups, but statistically different and no relationship was found between the results. All the refractive, topographic and visual acuity results were similar between both groups. Endothelial rejection was more frequent in Group II. Only three grafts lost graft clarity. These patients belonged to Group II. CONCLUSION: In a corneal referral practice, the visual results after PK were similar to those related to the PK performed by either expert surgeons or in training.

Laboratory detection methods for methicillin resistance in coagulase negative Staphylococcus isolated from ophthalmic infections.

PURPOSE: To evaluate different methods of oxacillin susceptibility testing of ocular isolates, considering polymerase chain reaction (PCR) as the 'gold standard', and to compare the in vitro susceptibility to oxacillin with that of other antimicrobials used in ophthalmologic practice. METHODS: The Vitek gram-positive identification card was used to identify ocular coagulase negative Staphylococcus species. The presence of the mecA gene was determined by the polymerase chain reaction assay with a combination of two primer sets (mecA and 16S rRNA) in a single region. Results were analyzed and compared with other oxacillin susceptibility methods: PBP2a detection by rapid slide latex agglutination test (SLA); oxacillin E-test; the Vitek automated gram-positive susceptibility card (GPS-105); the oxacillin salt agar screening test (OSAS) at a concentration of 6.0, 1.0 and 0.75 microg oxacillin per ml and the cefoxitin disk diffusion test (CDD). Automated susceptibility was also determined to other antimicrobial agents (fluoroquinolones, penicillin G, amoxicillin-ampicillin, cefazolin, ampicillin-sulbactam, erythromycin, clindamycin, gentamicin, tetracycline, trimethoprim-sulfamethoxazole, vancomycin and rifampin. RESULTS: Of the 69 CoNS isolates tested, 71% were mecA-positive and 29% mecA-negative. All methods tested had a statistically significant agreement with polymerase chain reaction. There was a tendency of positive polymerase chain reaction predomination among the S. epidermidis isolates in comparison to non-epidermidis isolates, although this was not statistically significant (78.3% vs. 56.5%; chi2= 2.54; P= 0.11). The oxacillin salt agar screening test (0.75 microg oxacillin/ml) showed the best performance, with 100% sensitivity and negative predictive value; 95% specificity and 98% positive predictive value. Using the E-test, the mecA-positive isolates were statistically significantly more resistant to ciprofloxacin, ofloxacin, gatifloxacin and moxifloxacin (P= 0.002; P= 0.008; P= 0.002 and P= 0.003, respectively). There was a statistically significant higher proportion of resistance of the coagulase negative Staphylococcus mecA-positives for: penicillin G, amoxicillin-ampicillin, cefazolin, ampicillin-sulbactam, erythromycin, clindamycin, gentamicin and tetracycline (P< or =0.05). All coagulase negative Staphylococcus species were susceptible to vancomycin and there was no statistically significant correlation between the mecA-positive isolates and resistance to trimethoprim-sulfamethoxazole or to rifampin. CONCLUSIONS: In the present study, we found that the E-test and the oxacillin salt agar screening test S (0.75 microg oxacillin per ml), when compared with polymerase chain reaction, were the most accurate currently available methods to phenotypically detect oxacillin resistance of coagulase negative Staphylococcus species. This study demonstrated that a good option for screening of ocular isolates for oxacillin resistance in the microbiology laboratory is the cefoxitin disk diffusion test and the automated Vitek system. We believe it is important to have available methods that accurately detect methicillin resistance of the less commonly encountered species, chiefly because of their increasing importance as opportunistic pathogens.

Results with the Boston Type I keratoprosthesis after Acanthamoeba keratitis.

PURPOSE: To report the outcomes of implantation of the Boston Type I keratoprosthesis in three patients with Acanthamoeba keratitis (AK), a severe infection that can lead to significant visual loss. OBSERVATIONS: Case series reporting three patients with difficult cases of AK that needed multiple corneal transplantations and glaucoma surgeries. All patients were implanted with the Boston Type I keratoprosthesis device. The main outcomes measure were the visual function and anatomical retention after implantation of the Boston Type I keratoprosthesis. All patients retained the device over the long-term and had good visual function. In one patient a retroprosthetic membrane developed and in another patient an epithelial lip developed over the anterior surface of the keratoprosthesis. The visual acuities range from 20/25 to 20/80 in the implanted eyes. CONCLUSIONS AND IMPORTANCE: The Boston Type I keratoprosthesis resulted in good anatomic and functional results after multiple graft failures after AK.

Indications and visual outcomes of intrastromal corneal ring segment implantation in a large patient series.

OBJECTIVES:: To describe the indications for and visual outcomes of intrastromal corneal ring segment implantation. METHODS:: A large retrospective case-series chart-review study was conducted using Sorocaba Ophthalmological Hospital medical records. This study included 1222 eyes (1196 patients) that were surgically treated between November 2009 and December 2012. The following preoperative data were collected: age, gender, type of medical care and funding source, surgical technique, best-corrected visual acuity, manifest sphere and cylinder refractive error, maximum and minimum central keratometry, and pachymetry measurements of the cornea at the thinnest point and at the ring channel. The postoperative best-corrected visual acuity and patient satisfaction were also determined. The cases were classified into six groups: four keratoconus groups (severe, advanced, moderate and mild), a pellucid marginal degeneration group and a post-graft irregular astigmatism group. This study was approved by the Brazilian Registry of Clinical Trials (UTN number 1111-1182-6181, TRIAL RBR-6S72RF). RESULTS:: The age (mean±standard deviation) of the patients was 31.0±10.0 years. The most prevalent pathology was keratoconus (1147 eyes, 93.8%). A correlation was found between ectasia severity and medical assistance (p<0.001), and the most serious cases was treated by the Brazilian public health system. No complications were found in a total of 1155 surgeries, and after surgery, 959 patients were satisfied. Among the 164 dissatisfied patients, the majority failed to show improved best-corrected visual acuity. CONCLUSION:: Patients in the public health system underwent surgical intervention for keratoconus later than those with private sources of funding. In the vast majority of operated cases, the patients reported improvements in vision.

[Bilateral epibulbar rheumatoid nodulosis: case report]. / Nodulose reumatóide epibulbar bilateral: relato de caso.

A 64-year-old woman with a diagnosis of rheumatoid arthritis developed painless bilateral episcleral rheumatoid nodules without any flare-up of her associated disease. Biopsy of the lesions disclosed a lymphocytic and plasmacytic infiltration within the conjunctiva, overlying palisading granulomas with multinucleated giant cells, and central necrobiotic degeneration of the collagen of the episclera and superficial sclera. The rheumatologic designation for the development of groups of nodules in inactive rheumatoid arthritis is rheumatoid nodulosis.

Efficacy and safety of recurrent pterygium surgery using human processed pericardium.

PURPOSE: To investigate the safety and efficacy of human processed pericardium used as an onlay after pterygium excision. METHODS: Twenty-five eyes of 25 patients (11 female, 14 male) with recurrent pterygium were included in this study. The median age was 50 years (range 24-89 years). Twenty-eight percent of the eyes previously had been operated on two or more times. The mean follow-up was 9.4 months (+/- 2.1 months, range 8-15 months). Following bare-sclera surgical removal of recurrent pterygium, a patch of processed human pericardium was sutured to cover the area of excision. The pericardium was not covered with conjunctiva, nor were adjuvant radiation or antimetabolite administered. All patients were treated with a combination of dexamethasone 0.1% / chloramphenicol drops three times per day for 1 month. Ketorolac tromethamine 0.5% three times per day was added to this regimen after complete corneal reepithelialization. RESULTS: Recurrence (any growth >1 mm onto the cornea) was detected in 12 patients (48%). The mean time of recurrence was 4.1 +/- 1.7 months. Three patients (12.0%) presented a regrowth of fibrovascular tissue not reaching 1 mm of the cornea. Pyogenic granulomas occurred in three patients, and all of them required surgical excision. Corneal thinning was present in one patient and was treated with a therapeutic contact lens and artificial tears with complete resolution and vascularization of the thinned area. No decrease in visual acuity was observed in any patient. CONCLUSIONS: The use of processed pericardium in pterygium surgery is a safe procedure but is associated with a relatively high rate of recurrence. It should only be considered as an option in managing recurrent pterygium when conjunctival autografting is not an available alternative.

Experience with Boston keratoprosthesis type 1 in the developing world.

OBJECTIVE: To report the experience of the Federal University of São Paulo, Brazil, in performing Boston keratoprosthesis type 1 implantation in the developing world. METHODS: We analyzed 30 eyes of 30 patients who underwent Boston type 1 keratoprosthesis surgery between 2008 and 2012 in a prospective interventional study. Preoperative, perioperative, and postoperative parameters were analyzed, including visual acuity (VA), keratoprosthesis stability, and postoperative complications. RESULTS: Preoperative diagnoses were failed grafts in 16 eyes (53.33%), chemical injury in 10 eyes (33.33%) and Stevens-Johnson syndrome in 4 eyes (13.33%). Also, 16 eyes (53.33%) had preoperative glaucoma. Preoperative best corrected VA ranged from 20/400 to light perception. With an average follow-up of 32 months (range 1-55 months), postoperative vision improved to >20/200 in 24 eyes (80%). Postoperative VA was statistically improved compared with the preoperative measurement during all postoperative follow-ups (up to 36 months). During the follow-up period (32 months), retention of the initial keratoprosthesis was 93.3%. The incidence of retroprosthetic membrane was 26.66%. Progression of glaucoma occurred in 7 of 16 eyes (43%). Three patients experienced development of glaucoma after keratoprosthesis implantation. One eye experienced development of infectious keratitis, and 2 eyes had retinal detachment. CONCLUSIONS: Performing Boston type 1 keratoprosthesis in a developing country is a viable option after multiple keratoplasty failures and conditions with a poor prognosis for keratoplasty. Our experience appears similar to major reports in the field from investigators in developed countries. Adjustments to postoperative management must be considered according to the particular location.

Boston type 1 keratoprosthesis outcomes in ocular burns.

PURPOSE: To report the outcomes of Boston type I keratoprosthesis (BKPro) in the management of ocular burn injuries. METHODS: This was a prospective study including all cases of BKPro implantation for ocular burns at the External Diseases and Cornea Service of the Federal University of São Paulo, between February 2008 and February 2010. Ten patients (10 eyes) were enrolled. Procedures performed to manage ocular injury were identified, and data were collected regarding patients' ocular history, surgical procedure(s) performed, and postoperative outcomes, including visual acuity, retention, complications and required surgical procedures. RESULTS: A total of 11 Type 1 BKPro were implanted in 10 eyes of 10 patients. The mean follow-up period was 25.7 ± 10.8 months. Preoperative best-corrected visual acuity (BCVA) ranged from count fingers to light perception. Postoperative BCVA was better than 20/200 in 90% of the patients and better than 20/60 in 60% of the patients. The overall BKPro retention rate was 90%. The most common complications were retroprosthetic membrane formation (50%) and persistent corneal epithelial defect evolving to corneal melting (40%). Patients who underwent ocular surface procedures such as limbal transplantation prior to BKPRo implantation had a lower incidence of corneal melting/thinning (p = 0.07), although this was not statistically significant. CONCLUSION: The anatomical and functional results identified in this study support the use of BKPro in managing bilateral limbal stem cell deficiency secondary to ocular burns.

Microbiota evaluation of patients with a Boston type I keratoprosthesis treated with topical 0.5% moxifloxacin and 5% povidone-iodine.

PURPOSE: To evaluate the efficacy of a prophylactic regimen of daily topical 0.5% moxifloxacin and 5% povidone-iodine (PI) in patients with Boston type I keratoprosthesis (KPro) and to assess the applicability of a novel molecular diagnostic technique to analyze the ocular surface microbiota in these patients. METHODS: Ten patients had their inferior conjunctival fornix sampled for standard culture methods before the addition of topical 5% PI to the prophylactic regimen and were considered the control group (group 1). The inferior conjunctival fornix and the KPro-donor cornea interface of 10 patients treated with the mentioned prophylactic regimen were sampled and analyzed by standard culture methods and using a polymerase chain reaction/electrospray ionization mass spectrometry assay (group 2). RESULTS: Samples from the inferior conjunctival fornix were positive for coagulase-negative staphylococcus in 3 patients and for Aerobasidium pullulans in 1 patient in group 1. The inferior conjunctival fornix and the KPro-donor cornea interface scrapings were positive for coagulase-negative staphylococcus in 2 patients and 1 patient, respectively, in group 2. No bacteria and fungi growth were detected in any patient from group 2 with the molecular diagnostic approach. None of the patients with culture-positive results developed keratitis or endophthalmitis during the study. CONCLUSIONS: Topical 0.5% moxifloxacin associated with topical 5% PI is an effective prophylactic regimen in patients with Boston type I KPro. The molecular diagnostic approach using serial polymerase chain reaction and mass spectrometry was comparable with standard microbiologic techniques as a surveillance tool in these patients.

Indications and visual outcomes of intrastromal corneal ring segment implantation in a large patient series

OBJECTIVES: To describe the indications for and visual outcomes of intrastromal corneal ring segment implantation. METHODS: A large retrospective case-series chart-review study was conducted using Sorocaba Ophthalmological Hospital medical records. This study included 1222 eyes (1196 patients) that were surgically treated between November 2009 and December 2012. The following preoperative data were collected: age, gender, type of medical care and funding source, surgical technique, best-corrected visual acuity, manifest sphere and cylinder refractive error, maximum and minimum central keratometry, and pachymetry measurements of the cornea at the thinnest point and at the ring channel. The postoperative best-corrected visual acuity and patient satisfaction were also determined. The cases were classified into six groups: four keratoconus groups (severe, advanced, moderate and mild), a pellucid marginal degeneration group and a post-graft irregular astigmatism group. This study was approved by the Brazilian Registry of Clinical Trials (UTN number 1111-1182-6181, TRIAL RBR-6S72RF). RESULTS: The age (mean±standard deviation) of the patients was 31.0±10.0 years. The most prevalent pathology was keratoconus (1147 eyes, 93.8%). A correlation was found between ectasia severity and medical assistance (p<0.001), and the most serious cases was treated by the Brazilian public health system. No complications were found in a total of 1155 surgeries, and after surgery, 959 patients were satisfied. Among the 164 dissatisfied patients, the majority failed to show improved best-corrected visual acuity. CONCLUSION: Patients in the public health system underwent surgical intervention for keratoconus later than those with private sources of funding. In the vast majority of operated cases, the patients reported improvements in vision.

Amniotic membrane transplantation for partial and total limbal stem cell deficiency secondary to chemical burn.

PURPOSE: To evaluate the surgical outcome of preserved amniotic membrane transplantation (AMT) for ocular surface reconstruction in chemical burn with limbal stem cell deficiency. DESIGN: Prospective, noncomparative, interventional case series. PARTICIPANTS: Twenty eyes of 20 consecutive patients with limbal stem cell deficiency secondary to ocular chemical injury. INTERVENTION: AMT with or without adjunctive limbal transplantation using limbal tissue from either the healthy contralateral eye (CLAU) or a living related donor (lr-CLAL). MAIN OUTCOME MEASURES: Reconstruction of corneal epithelium (clear appearance without epithelial defect, normal fluorescein permeability and the absence of conjunctiva-derived goblet cells on impression cytology), decrease in corneal vascularization and improvement in visual acuity. RESULTS: With a mean follow-up time of 19 months (range, 8-27 months), satisfactory ocular surface reconstruction was obtained in 15 eyes (75%), with reduced inflammation and vascularization of the ocular surface and a mean epithelialization time of 3.3 weeks. Success was observed in all cases of partial limbal stem cell deficiency (PLD) and in 68.75% (11 eyes) of cases of total limbal stem cell deficiency (TLD). Surgical failure was observed in five severe cases (31.25%). A significant visual improvement was observed in all cases after surgery, except for 2 eyes that maintained preoperative visual acuity. CONCLUSIONS: AMT seems to be an efficient adjunct for ocular surface reconstruction in chemical burns with PLD. When performed in conjunction with limbal stem cell transplantation, it is also effective in most cases of TLD.