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Biomedical subjects

G A Byrnes

Publications and source records attributed to G A Byrnes.

10 recordsLinked to original sources
PubMed1998

Long-term follow-up of iatrogenic phototoxicity.

OBJECTIVE: To evaluate the outcomes of a group of patients who suffered iatrogenic phototoxic injury. METHODS: The medical records of 24 patients (24 eyes) with iatrogenic phototoxicity from 3 medical centers were reviewed. We report the findings from long-term follow-up of these patients with particular attention to visual outcome, type and duration of procedure, and location of the phototoxic lesion. RESULTS: Phototoxic injury occurred after anterior segment surgery in 20 eyes and after vitrectomy in 4 eyes. The mean duration of surgery was 109 minutes; there was no statistically significant difference in duration between the anterior segment procedures and the vitrectomies. Mean final visual acuity was 20/40 for all cases (range, 20/15 to counting fingers) and 20/25 for all anterior segment cases. In vitrectomized eyes, the mean final visual acuity was 20/900. Phototoxic lesions tended to spare the fovea after anterior segment surgery and involve the foveal center after vitrectomy. CONCLUSIONS: In general, patients who suffer phototoxicity do well, and the prognosis is good for extrafoveal lesions. Foveal injury, which often occurs with vitrectomy, usually leads to a worse visual outcome. The development of choroidal neovascularization may have an effect on the ultimate visual outcome as well.

Aged↗
PubMed1996

Fluorescein angiography in the progressive outer retinal necrosis syndrome.

PURPOSE: Progressive outer retinal necrosis syndrome is a devastating retinopathy seen primarily in patients with acquired immune deficiency syndrome. To provide additional details of the pathogenesis of this disease, the authors describe the evolution of clinical and fluorescein angiographic changes during the course of progressive outer retinal necrosis syndrome. METHODS: The authors performed serial clinical examinations, fundus photography, and fluorescein angiography in a patient with acquired immune deficiency syndrome with progressive outer retinal necrosis syndrome. Clinical and fluorescein angiographic findings were correlated to provide detailed sequential analysis of the pathologic changes occurring during the course of this disorder. RESULTS: The angiographic changes seen during the various stages of the disease consisted of zonal microvascular alterations, retinal pigment epithelium (RPE) destruction, and choroidal leakage. Retinal damage was correlated closely with regions of choroidal leakage and was clinically evident as outer retinal whitening. Disease reactivation occurred as a prominent brush-fire border of intense leakage involving the retina, RPE, and choroid. Extensive damage to the retinal vasculature and RPE was noted in the wake of clinical infection. CONCLUSIONS: The angiographic findings in our patient demonstrate that the progressive outer retinal necrosis syndrome is a retinochoroiditis that involves the full thickness of retina as well as the RPE and choroid. The inflammatory changes seen throughout the course of this disease correlate with the histopathologic patterns reported to date.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Diabetic papillopathy. Patient characteristics and fundus findings.

OBJECTIVE: To better define the spectrum of patient characteristics and fundus findings in patients with a presumably unique clinical entity referred to as diabetic papillopathy. DESIGN: Retrospective series. SETTING: A university-based referral practice. METHODS: We retrospectively reviewed the medical records of all diabetic patients with benign, transient disc swelling who were evaluated at our institution from 1986 to 1992. Data pertaining to patient demographics, visual acuity and symptoms, disc and retinal findings, ancillary test results, and clinical course were collected. RESULTS: Twenty-seven eyes of 19 patients met the study definition of diabetic papillopathy. Patients were generally older (mean age, 50 years) and of a broader age range (19 to 79 years) compared with those in prior reports. Two thirds of patients had type II diabetes. Disc swelling was consistently hyperemic and, on average, resolved within 3.7 months. Macular edema was a frequent associated finding (70% of eyes) as was significant capillary nonperfusion (52% of tested eyes). Only four eyes (15%) had final visual acuities of less than 20/50 and each had prominent macular edema. Cup-disc ratio analysis of uninvolved eyes revealed a significantly small physiologic cup. CONCLUSIONS: The clinical profile of diabetic papillopathy can be expanded to include people who are older or have type II diabetes and that affected eyes commonly have macular edema or retinal vascular changes that can adversely affect the visual outcome. Last, a small physiologic cup may represent an anatomic predisposition to the condition.

Adult↗
PubMed1995

Prospective incidence of photic maculopathy after cataract surgery.

PURPOSE/METHODS: To determine the incidence of photic retinal injury during cataract surgery, we studied 37 consecutive patients with intravenous fluorescein angiography within ten days after cataract surgery. The microscope irradiance was standardized for all cases. RESULTS/CONCLUSIONS: Fluorescein evidence of photic retinal injury did not develop in any of the 37 cataract patients. Incidence rates for photic retinal injury induced by the surgical microscope vary considerably among ophthalmologists and most likely reflect differences in microscope brightness, surgical duration, and surgical technique.

Cataract Extraction↗
PubMed1995

Vitrectomy for ciliary block (malignant) glaucoma.

BACKGROUND: Ciliary block (malignant) glaucoma is a rare surgical complication occurring in patients with pre-existing glaucoma. Misdirected aqueous fluid causes forward movement of the lens/iris diaphragm, shallowing the central and peripheral anterior chamber. Although most patients with ciliary block respond to medical or laser therapy, those with refractory glaucoma often require pars plana vitrectomy to normalize aqueous flow. METHODS: The medical records of 21 consecutive patients with refractory ciliary block glaucoma treated by pars plana vitrectomy were reviewed retrospectively to determine the efficacy of this procedure in alleviating ciliary block. Data were collected regarding anatomic characteristics of the eye, history of glaucoma, prior ocular surgery, and outcome after vitrectomy. RESULTS: Pre-existing glaucoma and recent intraocular surgery were noted in all patients with ciliary block glaucoma. Of 21 eyes, 8 (38%) had undergone multiple prior intraocular surgeries. The initial pars plana vitrectomy was successful in alleviating ciliary block in 14 (70%) of 20 eyes. Of those six eyes that failed to improve after initial vitrectomy, five (83%) were phakic. Additional vitrectomy surgery to relieve ciliary block was required in three (60%) of five phakic patients who failed initial vitrectomy. Complications during the treatment of ciliary block included cataract formation, retinal detachment, bleb failure, and serous choroidal detachment. CONCLUSIONS: Pars plana vitrectomy is a useful adjunct to therapy for ciliary block glaucoma when medical and laser treatment fail to alleviate the process. Surgically removing the anterior hyaloid to re-establish normal aqueous flow constitutes the primary goal of surgery. In some cases, surgery is compromised by poor visualization of the anterior hyaloid, avoiding glaucoma filtration sites, and guarding against damage to the crystalline lens.

Anterior Chamber↗
PubMed1992

Photic maculopathy after extracapsular cataract surgery. A prospective study.

Photic retinal injuries have been described after surgical exposure to the intense illumination systems of operating microscopes. The overall incidence of such injuries has been postulated at less than 10%. The authors prospectively studied 43 consecutive patients to determine the incidence of photic macular injuries during cataract surgery. Patients underwent complete ophthalmic examinations, fundus photography, and oral fluorography before and after surgery. Photic macular injuries developed in 12 of 43 eyes (28%) as a result of intraocular surgery. This incidence is much higher than previous estimates. The association with possible risk factors, cystoid macular edema, and the effect of these injuries on final visual acuity are discussed.

Cataract Extraction↗