Aqueous Shunt Exposure
Aqueous Shunt Exposure
A retrospective review of charts from the Hermann Eye Center/Robert Cizik Eye Clinic of the Richard S. Ruiz, MD, Department of Ophthalmology and Visual Science at the University of Texas Medical School in Houston (UTH) and the Bascom Palmer Eye Institute at the Miller School of Medicine, University of Miami (BPEI) was performed. The Institutional Review Boards at the University of Texas and the University of Miami approved the separate parts of this study independently. Cases were identified by conducting a computerized search of the current procedural terminology code for repair of glaucoma drainage device (66185). Charts were included from all patients (22) who underwent revision of a previously placed aqueous shunt because of conjunctival erosion over the tube or the reservoir from 1995 to 2007 at UTH. Using the same criteria, 21 patients were included from BPEI who had aqueous shunt revision between 2001 and 2005.
Patient information was collected from charts using Institutional Review Board-approved uniform data collection sheets in full compliance with the Health Insurance Portability and Accountability Act regulations and in an anonymous fashion. All research methods were in compliance with the Declaration of Helsinki. After data collection, both patient populations were combined into 1 unified data set. Preoperative data collected included age at time of initial implantation, sex, race, history of hypertension, history of diabetes, history of an autoimmune disorder, family history (ocular disease, diabetes, or hypertension), and type of glaucoma. Baseline values were recorded from the most recent office visit preceding initial implantation. Baseline values recorded included study eye, number of topical glaucoma medications used, history of previous ocular surgery on the study eye (cataract surgery, trabeculectomy, bleb needling, laser surgery, cyclophotocoagulation, argon laser trabeculectomy, retinal surgery, and vitrectomy), previous pertinent ocular history, preoperative visual acuity, and preoperative IOP. All types of glaucoma were included, and no patients were excluded based on the severity of disease.
Forty-three eyes that underwent aqueous shunt revisions after aqueous shunt implantation with either anterior chamber or pars plana placement were retrospectively reviewed. Thirty-nine eyes were implanted with the Baerveldt Glaucoma implant (Abbott Medical Optics, Santa Ana, CA), 3 eyes with the Ahmed Glaucoma Valve (New World Medical, Inc, Rancho Cucamonga, CA), and 1 with the Krupin Eye Valve (E. Benson Hood Lab, Inc, Pembroke, MA). Type of shunt used, date of surgery, location of entry site into the eye (anterior chamber or pars plana), any concurrent surgical procedures, type of patch graft material used to cover the tube, and types of suture used for attaching the plate to the sclera, securing the tube to the sclera, and closing the conjunctiva were collected regarding the initial shunt implantation. All intraoperative complications were recorded.
Date of diagnosis of initial exposure, location of exposure, prerevision visual acuity and IOP, date of repair, setting for repair (operating room or minor procedure suite), method for closing the defect, type of patch graft used to cover the tube (if necessary), and types of sutures used to reattach the plate (if necessary), to secure the tube to the sclera (if necessary), and to close conjunctiva were collected regarding the exposures and their repairs. All complications were noted.
Data were collected from the office visits that were closest to postoperative week 1, and months 1, 2, 3, 6, 12, and 24 after aqueous shunt revision. Date of follow-up, visual acuity, IOP, relevant comments by the examiner, number of topical glaucoma medications, additional interventions performed, and reasons for further surgical interventions were collected from follow-up visits. All postoperative complications were included regardless of the time of occurrence. Timing of postoperative complications was recorded as time from the initial revision in weeks rounded to within 3 days.
Descriptive statistics, mean and SD, were calculated for continuous variables, that is age, IOP, etc, and frequency and percentage were calculated for qualitative measurements, that is sex, race, primary diagnosis, etc. Probability of not requiring revision/removal of aqueous shunt was estimated by Kaplan-Meier survival method. A stepwise Cox regression model was used to identify the risk factors associated with subsequent revision after the first repair. Poisson regression with backward elimination procedure was used to identify variables associated with increased risk of additional intervention. The risk factors studied in both the Cox regression model and the Poisson regression were sex, race (black vs. Hispanic vs. others), history of diabetes mellitus, type of glaucoma (primary open-angle glaucoma vs. others), number of topical glaucoma medications used before shunt implantation, earlier glaucoma surgery, earlier glaucoma laser surgery, earlier bleb needling, earlier retinal surgery, earlier vitrectomy, shunt implantation combined with other surgery, exposure occurred over the tube, and revision with or without scleral patch.
Patients and Methods
A retrospective review of charts from the Hermann Eye Center/Robert Cizik Eye Clinic of the Richard S. Ruiz, MD, Department of Ophthalmology and Visual Science at the University of Texas Medical School in Houston (UTH) and the Bascom Palmer Eye Institute at the Miller School of Medicine, University of Miami (BPEI) was performed. The Institutional Review Boards at the University of Texas and the University of Miami approved the separate parts of this study independently. Cases were identified by conducting a computerized search of the current procedural terminology code for repair of glaucoma drainage device (66185). Charts were included from all patients (22) who underwent revision of a previously placed aqueous shunt because of conjunctival erosion over the tube or the reservoir from 1995 to 2007 at UTH. Using the same criteria, 21 patients were included from BPEI who had aqueous shunt revision between 2001 and 2005.
Patient information was collected from charts using Institutional Review Board-approved uniform data collection sheets in full compliance with the Health Insurance Portability and Accountability Act regulations and in an anonymous fashion. All research methods were in compliance with the Declaration of Helsinki. After data collection, both patient populations were combined into 1 unified data set. Preoperative data collected included age at time of initial implantation, sex, race, history of hypertension, history of diabetes, history of an autoimmune disorder, family history (ocular disease, diabetes, or hypertension), and type of glaucoma. Baseline values were recorded from the most recent office visit preceding initial implantation. Baseline values recorded included study eye, number of topical glaucoma medications used, history of previous ocular surgery on the study eye (cataract surgery, trabeculectomy, bleb needling, laser surgery, cyclophotocoagulation, argon laser trabeculectomy, retinal surgery, and vitrectomy), previous pertinent ocular history, preoperative visual acuity, and preoperative IOP. All types of glaucoma were included, and no patients were excluded based on the severity of disease.
Forty-three eyes that underwent aqueous shunt revisions after aqueous shunt implantation with either anterior chamber or pars plana placement were retrospectively reviewed. Thirty-nine eyes were implanted with the Baerveldt Glaucoma implant (Abbott Medical Optics, Santa Ana, CA), 3 eyes with the Ahmed Glaucoma Valve (New World Medical, Inc, Rancho Cucamonga, CA), and 1 with the Krupin Eye Valve (E. Benson Hood Lab, Inc, Pembroke, MA). Type of shunt used, date of surgery, location of entry site into the eye (anterior chamber or pars plana), any concurrent surgical procedures, type of patch graft material used to cover the tube, and types of suture used for attaching the plate to the sclera, securing the tube to the sclera, and closing the conjunctiva were collected regarding the initial shunt implantation. All intraoperative complications were recorded.
Date of diagnosis of initial exposure, location of exposure, prerevision visual acuity and IOP, date of repair, setting for repair (operating room or minor procedure suite), method for closing the defect, type of patch graft used to cover the tube (if necessary), and types of sutures used to reattach the plate (if necessary), to secure the tube to the sclera (if necessary), and to close conjunctiva were collected regarding the exposures and their repairs. All complications were noted.
Data were collected from the office visits that were closest to postoperative week 1, and months 1, 2, 3, 6, 12, and 24 after aqueous shunt revision. Date of follow-up, visual acuity, IOP, relevant comments by the examiner, number of topical glaucoma medications, additional interventions performed, and reasons for further surgical interventions were collected from follow-up visits. All postoperative complications were included regardless of the time of occurrence. Timing of postoperative complications was recorded as time from the initial revision in weeks rounded to within 3 days.
Descriptive statistics, mean and SD, were calculated for continuous variables, that is age, IOP, etc, and frequency and percentage were calculated for qualitative measurements, that is sex, race, primary diagnosis, etc. Probability of not requiring revision/removal of aqueous shunt was estimated by Kaplan-Meier survival method. A stepwise Cox regression model was used to identify the risk factors associated with subsequent revision after the first repair. Poisson regression with backward elimination procedure was used to identify variables associated with increased risk of additional intervention. The risk factors studied in both the Cox regression model and the Poisson regression were sex, race (black vs. Hispanic vs. others), history of diabetes mellitus, type of glaucoma (primary open-angle glaucoma vs. others), number of topical glaucoma medications used before shunt implantation, earlier glaucoma surgery, earlier glaucoma laser surgery, earlier bleb needling, earlier retinal surgery, earlier vitrectomy, shunt implantation combined with other surgery, exposure occurred over the tube, and revision with or without scleral patch.
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