SAMIR JACOB BECHARA
Projetos de Pesquisa
Unidades Organizacionais
LIM/33 - Laboratório de Oftalmologia, Hospital das Clínicas, Faculdade de Medicina
8 resultados
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- 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.
- Corneal Collagen Cross-linking in Advanced Keratoconus: A 4-Year Follow-up Study(2016) GIACOMIN, Natalia T.; NETTO, Marcelo V.; TORRICELLI, Andre A. M.; MARINO, Gustavo K.; BECHARA, Samir J.; ESPINDOLA, Rodrigo F.; SANTHIAGO, Marcony R.PURPOSE: To analyze the safety and efficacy of standard corneal collagen cross-linking (CXL) in advanced cases of progressive keratoconus after 4 years of follow-up. METHODS: A retrospective case series of patients with advanced progressive keratoconus (stages 3 and 4 of Amsler-Krumeich classification) underwent standard CXL treatment. The parameters examined were changes in uncorrected visual acuity (UDVA), corrected visual acuity (CDVA), keratometry values (mean, flat, steep, and apical), pachymetry, and endothelial cell count at the baseline and at 12, 24, and 48 months postoperatively. RESULTS: Forty eyes of 40 patients were enrolled in the study. The mean patient age was 22.5 years (range: 15 to 37 years). Both mean UDVA and CDVA remained stable during the time points; no statistically significant change was noted. Although a slight reduction was observed in all keratometric readings, a statistically significant reduction was only reached in the apical keratometry (P = .037) at 4 years after CXL. A significant reduction in the corneal thickness was also found (ultrasonic: 388 +/- 49 to 379 +/- 48 mu m; slit-scanning: 362 +/- 48 to 353 +/- 51 mu m); however, this change was likely not clinically meaningful. Endothelial cell count was not significantly different at the end of the study. Treatment failure or progression was noted in two patients (5%) over the follow-up period. CONCLUSIONS: Standard CXL treatment was safe and able to stabilize both visual acuity and topographic parameters at 4 years of follow-up in eyes with advanced keratoconus.
- LASIK hipermetrópico pós-DSAEK (Descement Stripping Automated Endotelial Keratoplasty)(2016) MEIRELES, Antonio Carlos Manhas; BECHARA, Samir Jacob; MARTINES, EduardoABSTRACT DSAEK (Descemet stripping automated endothelial keratoplasty) is one of the options for corneal endothelium disease, which in some patients can result in a residual hyperopia after the procedure. Usually 6 to 12 months after corneal transplantation refraction is already stable. This report describes a therapeutic option used in a 54 years old patient with Fuchs' endothelial dystrophy submitted to cataract and corneal transplant that resulted in residual hyperopia, three years after the procedure the best corrected vision was 20/20 with a refraction of +3.25 -1.00 (5 º) treated with Hyperopic - LASIK (Laser-assisted In Situ Keratomileusis) with satisfactory visual result.
- Improved Evaluation of Postoperative Pain After Photorefractive Keratectomy(2016) GARCIA, Renato; HOROVITZ, Roberto Novaes Campello; TORRICELLI, Andre Augusto Miranda; MUKAI, Adriana; BECHARA, Samir JacobPurpose:Postoperative pain remains an important limiting factor to the selection of photorefractive keratectomy (PRK). There is a consensus in neurology pain research that pain should be evaluated as a multidimensional concept, which differs from current practice in ophthalmology. The purpose of this paper was to validate the use of multidimensional questionnaires, such as the Brief Pain Inventory (BPI) and the McGill Pain Questionnaire (MPQ), to provide an improved analysis of pain after PRK and to better describe its temporal profile.Methods:This prospective study included 43 eyes of 43 myopic patients who underwent unilateral PRK. After surgery, usual pain treatment was administered. All of the participants responded to the Visual Analogue Scale (VAS), the BPI and the MPQ 1, 24, 48, 72, and 96 hours after surgery. The internal consistency was evaluated, different postoperative periods were compared, and convergent validity was assessed using correlation testing.Results:The Cronbach alpha test showed high internal consistency for each of the questionnaire subscales. Patients reported higher postoperative pain values at the first measurement of the VAS (4.93 2.38), MPQ-pain rating index (26.95 +/- 10.58), BPI-pain severity index (14.53 +/- 7.36), and BPI-pain interference index (22.30 +/- 15.13). Almost all of the scales and subscales showed a statistically significant direct correlation with the VAS at all of the evaluation periods.Conclusions:This study validated the utility of multidimensional questionnaires to expand the assessment of the PRK postoperative pain profile, including intensity and other qualitative aspects.