SAMIR JACOB BECHARA
Projetos de Pesquisa
Unidades Organizacionais
LIM/33 - Laboratório de Oftalmologia, Hospital das Clínicas, Faculdade de Medicina
28 resultados
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article 39 Citação(ões) na Scopus Screening of Refractive Surgery Candidates for LASIK and PRK(2014) TORRICELLI, Andre A. M.; BECHARA, Samir J.; WILSON, Steven E.Purpose: The aim of this study was to evaluate exclusion criteria in screening patients for refractive surgery. Methods: Patients screened for initial refractive surgery by a single surgeon at the Cole Eye Institute (Cleveland Clinic) between 2007 and 2012 were reviewed. Exclusion criteria for patients who were not offered refractive surgery based on history and/or examination parameters were analyzed. Results: A total of 1067 refractive candidates were enrolled in the study. Five hundred nineteen (48.6%) were male and 548 (51.4%) were female with a mean age of 39 +/- 12 (range, 17-78) years. Refractive surgery was performed in 657 (61.6%) patients, and photorefractive keratectomy was considered the best option for 106 (9.9%) patients. Four hundred ten (38.4%) of all screened patients did not have refractive surgery, and 134 of these patients (12.6%) were considered to have contraindications for laser in situ keratomileusis and photorefractive keratectomy. Among the excluded patients, 69 (51.5%) were male and 65 (48.5%) were female with a mean age of 40 +/- 14 (range, 18-78) years. Abnormal corneal topography (34.3%) and low or insufficient corneal thickness (23.1%) were the most common reasons for exclusion. High myopia (10.5%) and (insipient or definite) cataract (9.7%) were also common reasons for exclusion. Other common factors for exclusion were high hyperopia (3.7%), need to wear reading glasses after surgery (3.7%), and severe dry eye unresponsive to treatment (3.7%). Conclusions: Abnormal corneal topography and low, or insufficient, corneal thickness remain the most common exclusion factors for corneal refractive surgery. Factors such as cataract, too high of correction, and severe dry eye are also common reasons for exclusion of patients.- Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C(2016) TORRICELLI, Andre Augusto Miranda; PAREDE, Tais Renata Ribeiro; NETTO, Marcelo Vieira; CRESTANA, Francisco Penteado; BECHARA, Samir JacobPurpose: To evaluate ocular straylight before and after photorefractive keratectomy (PRK) for low myopia with and without topical mitomycin (MMC) treatment. Methods: Patients who underwent PRK for low myopia were enrolled into the study. PRK without MMC was performed in 21 eyes (12 patients), whereas PRK with topical 0.02% MMC was performed in 25 eyes (14 patients). Both groups were treated using the NIDEK EC5000 excimer laser. Measurements were performed using the C-Quant straylight meter preoperatively and at two and four months postoperatively. Results: The mean patient age was 30 +/- 4 years, and the mean spherical equivalent refractive error was -2.2 +/- 0.75 D. The mean preoperative intraocular straylight values were 1.07 +/- 0.10 in the PRK without MMC group and 1.07 +/- 0.11 log(s) in the PRK with topical MMC group. At two months after surgery, there was a decrease in mean intraocular straylight values in both groups. However, a significant difference was only reached in the PRK with MMC group [0.98 +/- 0.09 log(s), p=0.002] compared with preoperative values, which was likely due to a greater scatter of measurements in the PRK without MMC group [1.03 +/- 0.13 log(s), p=0.082]. At four months postoperatively, ocular straylight values were not significantly different compared with those at baseline in either the PRK without MMC group [1.02 +/- 0.14 log(s), p=0.26] or in the PRK with topical MMC group [1.02 +/- 0.11 log(s), p=0.13]. Conclusion: PRK for low myopia decreases ocular straylight, and MMC application further reduces straylight in the early postoperative period. However, ocular straylight values do not significantly differ at four months after surgery compared with those at baseline.
- Mechanisms of Corneal Pain and Implications for Postoperative Pain After Laser Correction of Refractive Errors(2016) GARCIA, Renato; ANDRADE, Daniel C. de; TEIXEIRA, Manoel J.; NOZAKI, Siro S.; BECHARA, Samir J.Objective:The cornea is the target of most surgeries for refractive disorders, as myopia. It is estimated that almost 1 million patients undergo corneal refractive surgery each year in the United States. Refractive surgery includes photorefractive keratectomy (PRK) that produces intense postoperative pain. This review presents the main pain mechanisms behind PRK-related pain and the available therapeutic options for its management.Methods:Data sources included literature of cornea anatomy, treatment of PRK postoperative pain, mechanisms of corneal pain, in 3 electronic databases: Pubmed, Scopus, and Web of Science. Only double-blinded controlled trials on pain control after PRK were selected to show the endpoints, treatment, and control strategies.Results:A total of 18 double-blind, controlled trials were identified. These studies have shown the use of topical nonsteroidal anti-inflammatory drugs, topical steroidal anti-inflammatory drugs, systemic analgesics, cold balanced saline solution, topical anesthetic, gabapentin, and morphine to treat postoperative pain in PRK.Discussion:The percentage of responders has seldom been reported, and few studies allow for the formal calculation of the number necessary to treat. Postoperative intense pain after PRK laser surgery remains the main challenge to its widespread use for the correction of refractive errors.
article 9 Citação(ões) na Scopus Predictors of Early Postoperative Pain After Photorefractive Keratectomy(2016) GARCIA, Renato; TORRICELLI, Andre Augusto Miranda; MUKAI, Adriana; PEREIRA, Vinicius Borges Porfirio; BECHARA, Samir JacobPurpose: To compare the profiles of postoperative photorefractive keratectomy (PRK) pain between both eyes under the same conditions and to verify the preoperative predictors of pain such as gender, anxiety, knowledge of the procedure, and spherical equivalent refractive error (SERE). Methods: This prospective study included 86 eyes of 43 patients with myopia who underwent PRK in both eyes at an interval of 14 days between the procedures. Before surgery, subjects answered the State Anxiety Inventory. After surgery, usual PRK pain treatment was given. Subjects answered the Visual Analog Scale, the Brief Pain Inventory (BPI), and the McGill Pain Questionnaire at 1, 24, 48, 72, and 96 hours after surgery. Pain scores and anxiety were compared between each eye using the Wald test and paired Student t test, respectively. The Wald test was performed for gender and SERE for each eye separately. Results: There were no statistically significant differences between both eyes for all time points regarding the Visual Analog Scale, BPI, and McGill Pain Questionnaire Pain Rating Index pain scores. Subjects were less anxious on average before the second surgery compared with before the first surgery (P < 0.001); however, it was not related to pain ratings after surgery. Gender did not significantly affect any scale of pain, and the SERE between 3 diopters (D) and 5 D (P = 0.035) revealed effects on the BPI. Conclusions: The profiles of postoperative pain after PRK were similar between both eyes under the same conditions. In this study, a high SERE was the only predictor for increased pain after PRK.- Femtosecond Laser-Assisted LASIK Flap Complications(2016) SANTOS, Allisson Mario dos; TORRICELLI, Andre A. M.; MARINO, Gustavo K.; GARCIA, Renato; NETTO, Marcelo V.; BECHARA, Samir J.; WILSON, Steven E.PURPOSE: To discuss intraoperative and postoperative femtosecond laser-assisted LASIK flap complications and their management. METHODS: Review of published literature. RESULTS: Flap creation is a critical step in LASIK. The femtosecond laser has improved the overall predictability and safety of the lamellar incision, but complications can still occur during or after flap creation. Although many complications (eg, epithelial ingrowth and flap striae) were reduced with the femtosecond laser application, other specific complications have emerged, such as vertical gas breakthrough, opaque bubble layer, and transient light-sensitivity syndrome. CONCLUSIONS: The application of femtosecond laser technology to LASIK flap creation has increased greatly since its introduction. These lasers have improved the safety and predictability of the lamellar incision step. The majority of the femtosecond laser-assisted flap complications can be well managed without significant effects on refractive outcomes.
- Advances in femtosecond laser technology(2016) CALLOU, Thais Pinheiro; GARCIA, Renato; MUKAI, Adriana; GIACOMIN, Natalia T.; SOUZA, Rodrigo Guimaraes de; BECHARA, Samir J.Femtosecond laser technology has become widely adopted by ophthalmic surgeons. The purpose of this study is to discuss applications and advantages of femtosecond lasers over traditional manual techniques, and related unique complications in cataract surgery and corneal refractive surgical procedures, including: LASIK flap creation, intracorneal ring segment implantation, presbyopic treatments, keratoplasty, astigmatic keratotomy, and intrastromal lenticule procedures.
- Quality of vision in refractive and cataract surgery, indirect measurers: review article(2013) PAREDE, Tais Renata Ribeira; TORRICELLI, Andre Augusto Miranda; MUKAI, Adriana; NETTO, Marcelo Vieira; BECHARA, Samir JacobVisual acuity is the measurement of an individual's ability to recognize details of an object in a space. Visual function measurements in clinical ophthalmology are limited by factors such as maximum contrast and so it might not adequately reflect the real vision conditions at that moment as well as the subjective aspects of the world perception by the patient. The objective of a successful vision-restoring surgery lies not only in gaining visual acuity lines, but also in vision quality. Therefore, refractive and cataract surgeries have the responsibility of achieving quality results. It is difficult to define quality of vision by a single parameter, and the main functional-vision tests are: contrast sensitivity, disability glare, intraocular stray light and aberrometry. In the current review the different components of the visual function are explained and the several available methods to assess the vision quality are described.
- Codeine Plus Acetaminophen for Pain After Photorefractive Keratectomy: A Randomized, Double-Blind, Placebo-Controlled Add-On Trial(2017) PEREIRA, Vinicius B. P.; GARCIA, Renato; TORRICELLI, Andre A. M.; MUKAI, Adriana; BECHARA, Samir J.Background: Pain after photorefractive keratectomy (PRK) is significant, and the analgesic efficacy and safety of oral opioids in combination with acetaminophen has not been fully investigated in PRK trials. Purpose: To assess the efficacy and safety of the combination of codeine plus acetaminophen (paracetamol) versus placebo as an addon therapy for pain control after PRK. Study design: Randomized, double-blind, placebo-controlled trial. Setting: Single tertiary center. Methods: One eye was randomly allocated to the intervention, whereas the fellow eye was treated with a placebo. Eyes were operated 2 weeks apart. The participants were adults older than 20 years with refractive stability for >= 1 year, who underwent PRK for correction of myopia or myopic astigmatism. Codeine (30 mg) plus acetaminophen (500 mg) was given orally 4 times per day for 4 days after PRK. The follow-up duration was 4 months. The study outcomes included pain scores at 1 to 72 hours, as measured by the visual analog scale, McGill Pain Questionnaire, and Brief Pain Inventory, as well as adverse events and corneal wound healing. Results: Of the initial 82 eyes, 80 completed the trial (40 intervention, 40 placebo). Median (interquartile range) pain scores as measured by the visual analog scale were statistically and clinically lower during treatment with codeine/acetaminophen compared with the placebo: 1 hour: 4 (2-4) versus 6 (3-6), P, 0.001; 24 hours: 4 (3-6) versus 7 (6-9), P < 0.001; 48 hours: 1 (02) versus 3 (2-5), P < 0.001; and 72 hours: 0 (0-0) versus 0 (0-2), P = 0.001. Virtually identical results were obtained by the McGill Pain Questionnaire and Brief Pain Inventory scales. The most common adverse events with codeine/acetaminophen were drowsiness (42%), nausea (18%), and constipation (5%). No case of delayed epithelial healing was observed in both treatment arms. Conclusions: When added to the usual care therapy, the oral combination of codeine/acetaminophen was safe and significantly superior to the placebo for pain control after PRK.
bookPart Seleção do paciente, perfil psicológico e aspectos legais em cirurgia refrativa(2022) BECHARA, Samir Jacob- Longitudinal measurements of luminance and chromatic contrast sensitivity: comparison between wavefront-guided LASIK and contralateral PRK for myopia(2013) BARBONI, Mirella Telles Salgueiro; FEITOSA-SANTANA, Claudia; BARRETO JUNIOR, Jackson; LAGO, Marcos; BECHARA, Samir Jacob; ALVES, Milton Ruiz; VENTURA, Dora FixPURPOSE: The present study aimed to compare the postoperative contrast sensitivity functions between wavefront-guided LASIK eyes and their contralateral wavefront-guided PRK eyes. METHODS: The participants were 11 healthy subjects (mean age=32.4 ± 6.2 years) who had myopic astigmatism. The spatial contrast sensitivity functions were measured before and three times after the surgery. Psycho and a Cambridge graphic board (VSG 2/4) were used to measure luminance, red-green, and blue-yellow spatial contrast sensitivity functions (from 0.85 to 13.1 cycles/degree). Longitudinal analysis and comparison between surgeries were performed. RESULTS: There was no significant contrast sensitivity change during the one-year follow-up measurements neither for LASIK nor for PRK eyes. The comparison between procedures showed no differences at 12 months postoperative. CONCLUSIONS: The present data showed similar contrast sensitivities during one-year follow-up of wave-front guided refractive surgeries. Moreover, one year postoperative data showed no differences in the effects of either wavefront-guided LASIK or wavefront-guided PRK on the luminance and chromatic spatial contrast sensitivity functions.
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