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Biomedical subjects

Anat Loewenstein

Publications and source records attributed to Anat Loewenstein.

27 records · Page 2Linked to original sources

Excision of pterygium and conjunctival autograft.

BACKGROUND: Pterygium is a common disease in Israel. Different surgical techniques are used to manage it with varying degrees of success. OBJECTIVES: To evaluate the efficacy and safety of a conjunctival autograft after excision of pterygium. METHODS: Excision followed by conjunctival autograft was used to treat 40 eyes of 40 patients with pterygium. The surgical results were evaluated retrospectively. Follow-up continued for a median of 296 days (range 6-1,056); 26 cases were followed for more than 100 days (average 418 days) and comprised the study cohort. All reported procedures were performed consequentially and by one surgeon in the Tel Aviv Sourasky Medical Center, Israel between 1 June 1997 and 31 March 2000. RESULTS: There were two recurrences of pterygium (2/26, 7.7%) 2 months postoperatively. There were no major complications. Superficial comeal vessels (without concurrent fibrosis) appeared in 10 of 17 cases sutured with nylon, but none occurred in any of the seven grafts sutured with vicryl (P = 0.068). The average LogMAR-corrected visual acuity of the study group improved slightly, from 6/16.5 to 6/11 (P = 0.003). CONCLUSIONS: Excision of pterygium with a conjunctival autograft is a safe and effective operation, with no procedure-specific added surgical risks. The relatively long surgical time and microsurgical methods required to perform the procedure properly have hindered its acceptance as the mainstream approach to pterygium management. Long-term follow-up is needed for better discernment of the surgical results in Israel.

Adult↗

Retinal pathology occurring after excimer laser surgery or phakic intraocular lens implantation: evaluation of possible relationship.

The increasing number of patients undergoing refractive surgery has led to an awareness of the potential retinal complications of these procedures. The purpose of this review is to summarize the reports of retinal pathology and myopic maculopathy that have occurred after excimer refractive surgery or implantation of phakic intraocular lenses, and to evaluate theoretical pathogenetic mechanisms. We found it reasonable to conclude that retinal detachments and macular hemorrhages are not caused by laser surgery, but are rather characteristic of the natural history in the myopic eye. However, although there is no clear-cut evidence for a cause-and-effect relationship between excimer laser surgery and retinal pathology, it is very important to inform patients that refractive surgery only corrects the refractive aspect of myopia, and that the myopia itself still has the potential for serious complications.

Cornea↗

Results of a multicenter clinical trial to evaluate the preferential hyperacuity perimeter for detection of age-related macular degeneration.

PURPOSE: To compare the preferential hyperacuity perimeter (PHP) with an Amsler grid in detection of age-related macular degeneration (AMD). METHODS: Patients underwent refraction, visual acuity examination, PHP, Amsler grid examination, and macular photography. RESULTS: One hundred fifty patients participated in the trial. Of 19 eyes with neovascular AMD, 19 (100%) were positive on the PHP, and 10 (53%), on the Amsler grid. Of 27 eyes with geographic atrophy, 26 (96%) were positive on the PHP, and 12 (44%), on the Amsler grid. Of 20 eyes with intermediate AMD, 14 (70%) were positive on the PHP, and 4 (20%), on the Amsler grid. Of 51 eyes with early AMD, 21 (41%) were positive on the PHP, and 4 (8%), on the Amsler grid. Of 33 eyes with no AMD, 6 (18%) were positive on the PHP, and none, on the Amsler grid. Thus, 80 (68%) of 117 patients with AMD had a positive PHP, while 30 (26%) had positive results of Amsler grid examination (P < 0.001, McNemar test). CONCLUSION: The PHP had greater sensitivity, although with a relatively high rate of false-positive results for healthy individuals, than the Amsler grid in detecting AMD-related lesions.

Aged↗

Visual field defects after radial optic neurotomy for central retinal vein occlusion.

PURPOSE: Surgical decompression of the vein in central retinal vein occlusion (CRVO) by radial optic neurotomy (RON) was recently proposed as being surgically feasible, safe, and beneficial. The effect of RON on the visual field has not been systematically reported, although possible visual field defects are expected due to iatrogenic cutting of the optic nerve fibers. The authors report the results of visual field testing in patients who underwent RON at the Tel Aviv Medical Center. METHODS: Twelve consecutive patients (8 men, mean age of all patients 68 years) with nonperfused or indeterminate CRVO whose initial visual acuity (VA) was < or =20/400 underwent RON. Nine of these patients were able to perform visual field tests at 6 months post-RON and their visual field results are presented. RESULTS: : VA improved by > or =3 lines in 5 patients (42%). Three (25%) patients had a final VA of > or =20/200 and another had a final VA > or =20/50. Fundus and VA improvement were relatively slow. Two patients had clearing of the intraretinal blood, resolution of the venous dilation, and improved VA at the 2-month follow-up visit. Temporal visual field defects consisting of temporal ones that could be correlated to the site of the RON incision were detected in five out of the nine patients who were able to perform visual field tests. No temporal visual field defects were found in the remaining four patients, and three other patients were unable to perform visual field tests due to inability to identify the largest target size. CONCLUSION: VA improvement in 5 of 12 patients with ischemic or indeterminate CRVO following RON may be better than the natural history of CRVO. The risk of visual field defects may, however, be heightened by possibly cutting off blood supply to the optic nerve head and possible damage to nerve fibers in the optic nerve head, both inherent to the surgical procedure and both likely to produce visual loss.

Adult↗

Long-term results of superior oblique tendon elongation for Brown's syndrome.

PURPOSE: To evaluate superior oblique tendon lengthening technique in the treatment of congenital Brown's Syndrome. METHODS: Retrospective evaluation of 8 patients with Brown's syndrome (ages 2.5 to 8 years) who underwent superior oblique split tendon elongation as the primary procedure. RESULTS: The mean follow-up period was 35 months (range 18 to 72 months). Seven of 8 patients had complete resolution of the compensatory head posturing and downshoot in adduction, and achieved some ability to elevate the eye in adduction. One of the operated eyes required reoperation because head posture persisted and a tenectomy of the superior oblique tendon was performed with satisfactory results. CONCLUSIONS: The superior oblique split tendon lengthening technique is proposed as a possible procedure of choice for the treatment of Brown's syndrome.

Child↗

Macular hole secondary to branch retinal vein occlusion diagnosed by Retinal Thickness Analyzer.

The Retinal Thickness Analyzer is a laser slit biomicroscopy imaging device that produces accurate measurements of retinal thickness and displays the images in a two-dimensional pattern, superimposed on a fundus image. This article reports a patient with decreased vision following branch retinal vein occlusion in whom the Retinal Thickness Analyzer was used to establish the diagnosis of a macular lamellar hole that was not apparent clinically.

Diagnostic Techniques, Ophthalmological↗

Interferon alpha-2a for proliferative diabetic retinopathy after complete laser panretinal photocoagulation treatment.

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the effect of interferon alpha-2a, an angiogenesis inhibitor, on eyes with active neovascularization after complete laser panretinal photocoagulation treatment. PATIENTS AND METHODS: Eight patients with active neovascularization persisting for 6 months or more after completion of full panretinal photocoagulation were included in the study. All patients were treated with subcutaneous injections of 6 million international units of interferon alpha-2a, 3 times a week, for an average period of 10 months. Visual acuity, contrast sensitivity, blood tests, fundus photographs, fluorescein angiography, and physical examination were performed periodically. The main outcome measures were visual acuity and extent of neovascularization as assessed by fundus photography and fluorescein angiography. RESULTS: The 5 men and 3 women (mean age, 60 years) had a mean duration of diabetes of 19 years. The average study follow-up was 42.2 +/- 8.7 weeks. Visual acuity and extent of neovascularization improved or remained stable in 7 patients. In none of the patients was there progression of neovascularization, but in 1 patient it could not be assessed due to vitreous hemorrhage. Most patients had malaise during the first weeks of treatment, but none of the patients suffered from nonreversible side effects associated with interferon alpha-2a. CONCLUSION: This pilot study provides evidence that interferon alpha-2a might have a role in the regression of proliferative diabetic retinopathy and that further investigation is warranted.

Adult↗

A novel high-resolution kinetic method for visual field mapping of scotoma in age-related macular degeneration.

BACKGROUND AND OBJECTIVE: To examine a new high-resolution kinetic mapping method for scotoma in age-related macular degeneration. PATIENTS AND METHODS: A computer-based program for kinetic visual field mapping was tested in 10 healthy subjects and 14 patients with age-related macular degeneration and fixed preferred retinal locus. The stimulus was presented using a back projector on a screen located 40 cm from the subject. The findings were then compared with static results. RESULTS: Control group mapping revealed good congruency with the anatomic blind spot. Mapping of the 14 patients with age-related macular degeneration was rapid and revealed good accuracy. The average deviation of the mapping border from the anatomic scotoma border was no more than 3.1% of the scotoma radius. Static mapping of 7 of the patients with age-related macular degeneration was longer and revealed lower accuracy. CONCLUSIONS: The proposed method is more rapid, accurate, and consistent than static mapping. It allows accurate mapping of central scotoma with suprathreshold stimulus, and may be used in the future for detecting the early stages of age-related macular degeneration using subthreshold stimulus.

Adult↗