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Dive into the research topics where George W. Blankenship is active.

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Featured researches published by George W. Blankenship.


Ophthalmology | 1978

Photocoagulation Treatment of Proliferative Diabetic Retinopathy: The Second Report of Diabetic Retinopathy Study Findings

Arnall Patz; Stuart L. Fine; Daniel Finkelstein; Thaddeus E. Prout; Lloyd Paul Aiello; Robert Bradley; Jose C. Briones; Frank L. Myers; George H. Bresnick; Guillermo de Venecia; Thomas S. Stevens; Ingolf H. L. Wallow; Suresh R. Chandra; Edward W.D. Norton; George W. Blankenship; John E. Harris; William H. Knobloch; Frederick C. Goetz; Robert C. Ramsay; J. Wallace McMeel; Donald Martin; Morton F. Goldberg; Felipe U. Huamonte; Gholam A. Peyman; Bradley R. Straatsma; Stanley M. Kopelow; W.A.J. van Heuven; Aaron Kassoff; Stephen S. Feman; Robert C. Watzke

Data from the Diabetic Retinopathy Study (DRS) show that photocoagulad inhibited the progression of retinopathy. These beneficial effects were noted to some degree in all those stages of diabetic retinopathy which were included in the Study. Some deleterious effects of treatment were also found, including losses of visual acuity and constriction of peripheral visual field. The risk of these harmful effects was considered acceptable in eyes with retinopathy in the moderate or severe retinopathy in the moderate or severe proliferative stage when the risk of severe visual loss without treatment was great. In early proliferative or severe nonproliferative retinopathy, when the risk of severe visual loss without treatment was less, the risks of harmful treatment effects assumed greater importance. In these earlier stages, DRS findings have not led to a clear choice between prompt treatment and deferral of treatment unless and until progression to a more severe stage occurs.


Ophthalmology | 1985

Long-term Diabetic Vitrectomy Results: Report of 10 Year Follow-up

George W. Blankenship; Robert Machemer

Ten year follow-up examinations were obtained on 72 cases having pars plana vitrectomies for diabetic retinopathy complications from 1970 to 1973. Forty-two percent of the cases maintained 6/60 or better visual acuities through the tenth year. The visual results were quite stable, with 53% of the cases having the same or better visual acuities at ten years compared with six months. Neovascular glaucoma developed in 11 eyes, usually during the first six months, and open-angle glaucoma developed in 16 eyes, usually after the five-year follow-up examination. Both types of glaucoma occurred almost exclusively in aphakic eyes. Cataracts developed in 75% of retained clear lenses. The vitreous cavities remained clear in 67% of the eyes, and the maculas were attached in 65% of the eyes 10 years following vitrectomy. Fundus neovascularization did not recur.


Ophthalmology | 1997

Vision-threatening Complications of Surgery for Full-thickness Macular Holes

Alay S. Banker; William R. Freeman; Jung V. Kim; David Munguia; Stanley P. Azen; Jung W. Kim; Mei-Ying Lai; Gary W. Abrams; Rabbi Wayne Dosick; Sandy T. Feldman; Renata Ochabski; Stuart L. Fine; Ian L. Bailey; Thomas M. Aaberg; Brian B. Berger; George W. Blankenship; Alexander J. Brucker; Serge de Bustros; Akitoshi Yoshida; Howard D. Gilbert; Dennis P. Han; Gregg T. Kokame; Brooks W. McCuen; Donald A. Frambach; Joseph Olk; Jack O. Sipperley; Van W. Teeters; William J. Wood

OBJECTIVE To study complications of vitrectomy surgery for full-thickness macular holes. DESIGN A multicentered, randomized, controlled clinical trial. PARTICIPANTS Community and university-based ophthalmology clinics. INTERVENTION Standardized macular hole surgery versus observation. MAIN OUTCOME MEASURES Assessment of anatomic and visual outcomes and determination of postoperative complications at 12 months after randomization. RESULTS Posterior segment complications were noted in 39 eyes (41%). The incidence of retinal pigment epithelium (RPE) alteration and retinal detachment (RD) were 33% and 11%, respectively. One RD due to a giant retinal tear resulted in a visual acuity of light perception. Other complications included a reopening of the macular hole in 2 eyes (2%), cystoid macular edema in 1 eye (1%), a choroidal neovascular membrane in 1 eye (1%) and endophthalmitis in 1 eye (1%). Eyes with complications had significantly worse visual acuity outcomes as determined by the Early Treatment Diabetic Retinopathy Study, Word Reading, and Potential Acuity Meter charts (P < 0.01 for all comparisons). Eyes with macular holes greater than 475 microns were more than twice as likely to have complications than eyes with holes less than 475 microns (odds ratio [OR] = 2.2, P = 0.07). Before surgery, the stage of the hole was related to postoperative RPE changes (P < 0.0001) and the occurrence of postoperative RD (P = 0.0002). Intraoperative trauma was related to the occurrence of these complications (P < 0.0001 for RPE changes, P = 0.02 for RDs). Epiretinal membrane removal was related to RPE changes (P = 0.02) but not RDs. CONCLUSIONS The RPE alterations and RDs are common after macular hole surgery and result in significantly reduced postoperative visual acuity. The RPE changes may be related to surgical trauma or light toxicity. Further efforts to reduce complications associated with macular hole surgery are indicated.


American Journal of Ophthalmology | 1976

Pars Plana Vitrectomy for the Management of Severe Diabetic Retinopathy

Mark S. Mandelcorn; George W. Blankenship; Robert Machemer

In 100 severely diseased diabetic eyes we performed pars plana vitrectomy. After a median follow-up time of seven months, major visual improvement was achieved in 49% of the eyes. An additional four eyes maintained a preoperatively good visual acuity resulting in an overall success rate of 53%. Eyes with only vitreous hemorrhages did better (71%) than eyes with posterior retinal detachments (31%). We did not observe new tissue proliferation in any of the operated eyes.


Ophthalmology | 1979

Diabetic Macular Edema and Argon Laser Photocoagulation: A Prospective Randomized Study

George W. Blankenship

Loss of vision from diabetic retinopathy can result from complications of neovascular proliferation, or frequently, from macular edema secondary to background diabetic retinopathy. Although the benefits of photocoagulation for proliferative diabetic retinopathy have been clarified by the National Eye Institutes collaborative diabetic retinopathy study, those for background diabetic retinopathy with macular edema remain unclear. Several articles have described the visual benefits and reduction of edema following photocoagulation of eyes with background diabetic retinopathy and macular edema, but only Patzs study was prospectively designed utilizing a random assignment of laser treatment for one eye with the other eye remaining untreated. This article reports the two-year results of a similar prospective study in which one eye in each of 39 patients with symmetrical macular edema secondary to background diabetic retinopathy was randomly selected to receive argon laser photocoagulation, while the fellow eye remained untreated.


Ophthalmology | 1982

Single versus Multiple Treatment Sessions of Argon Laser Panretinal Photocoagulation for Proliferative Diabetic Retinopathy

Bernard H. Doft; George W. Blankenship

A prospective, randomized study was performed to demonstrate whether there was a difference in the beneficial or adverse effects of argon laser photocoagulation for proliferative diabetic retinopathy depending on whether treatment was administered in a single session as compared with multiple sessions spaced over time. Results show no major differences between groups in the effect of treatment on visual acuity, visual field scores, or retinopathy risk factors. Exudative retinal detachment, choroidal detachment, and angle closure occurred more commonly in single session treatment group eyes, but these effects were transient, and no long-term difference between treatment groups was found.


Ophthalmology | 1996

Central serous chorioretinopathy in women

David A. Quillen; J. Donald M. Gass; Roy D. Brod; Thomas W. Gardner; George W. Blankenship; Justin L. Gottlieb

BACKGROUND Central serous chorioretinopathy is a disorder that typically affects young and middle-aged men. Although extensive information is available pertaining to the clinical features of central serous chorioretinopathy in men, little is known about this condition in women. MATERIALS AND METHODS The authors reviewed the medical records and photographic files of women who received a diagnosis of central serous chorioretinopathy. The women were divided into three groups for data analysis: idiopathic, exogenous corticosteroid use, and pregnancy. RESULTS Fifty-one women with active central serous chorioretinopathy were evaluated. These findings in women with idiopathic serous chorioretinopathy were similar to those described in men, with the exception that women tend to be older at the time of onset. Central serous chorioretinopathy in women taking exogenous corticosteroids more likely was characterized by bilateral involvement and subretinal fibrin. Central serous chorioretinopathy in pregnant women typically developed in the third trimester and resolved spontaneously within 1-2 months after delivery. CONCLUSION Idiopathic central serous chorioretinopathy is similar in women and men, with the exception that women tend to be more older at the time of onset. The finding of exogenous corticosteroid use in a significant number of women in our study provides further support that cortisol may play a role in the development of central serous chorioretinopathy. The mechanism by which cortisol influences the development of central serous chorioretinopathy is unclear.


Ophthalmology | 1989

Posterior Chamber Intraocular Lens Implantation during Diabetic Pars Plana Vitrectomy

Gregg T. Kokame; Harry W. Flynn; George W. Blankenship

Combined cataract removal, posterior chamber intraocular lens (PC IOL) implantation, and pars plana vitrectomy were performed in 15 diabetic patients who presented with coexisting cataract and vitreoretinal complications from proliferative diabetic retinopathy (PDR). Posterior chamber IOLs were placed anterior to the anterior lens capsule after pars plana lensectomy and vitrectomy in nine eyes, whereas extracapsular cataract extraction (ECCE) with PC IOL placement was performed before vitrectomy in six eyes. Panretinal laser endophotocoagulation was applied in 13 of the 15 eyes as an important part of the operative procedure. Because of inactive diabetic retinopathy or satisfactory preoperative panretinal photocoagulation, 2 of the 15 eyes did not receive laser endophotocoagulation. Visual acuity was improved in 12 eyes and was similar to preoperative vision in 3 eyes. After a minimum of 6 months and a maximum of 28 months of follow-up, the visual results are the following: 20/40 or better (4 eyes), 20/50 to 20/200 (5 eyes), 20/400 to 5/200 (5 eyes), and hand motions (1 eye). Although 5 of the 15 eyes required secondary vitreoretinal procedures, neovascular glaucoma and complications attributable to the IOL did not occur. A recurrent postoperative retinal detachment (RD) developed with subsequent hypotony and rubeosis iridis in 1 of the 15 eyes.


Ophthalmology | 1981

Vitrectomy for Proliferative Diabetic Retinopathy Associated with Vitreous Hemorrhage

Robert Machemer; George W. Blankenship

This paper describes experience gained with 663 eyes of patients with diabetic vitreous hemorrhage treated by closed vitrectomy with a follow-up period of six months. Hemorrhages were nearly always associated with proliferative retinopathy (97%) and were thought to be caused always by ruptured proliferative vessels. Membrane removal was performed in 42% of all cases but in 60% when the retina was detached. The most common surgical complication was creation of retinal holes; more common when the posterior retina was detached (32%) than when it was attached (18%). The lens was removed in 73% of the cases. Eighty-two percent of the retained clear lenses remained clear at the six months follow-up period. Therefore, clear lenses should not be removed. Visual improvement could be achieved in 59% of the cases where the posterior retina was attached but only in 25% where it was detached resulting in an overall major visual improvement in 46% of the cases. If one adds to this group the cases that retained reasonable vision of 20/200 or better, the overall success rate was 51%. Posterior retinal detachment and rubeosis of the iris were the main factors for a bad prognosis. Forty-two percent of all eyes had at least some degree of rubeosis iridis. Most of the preoperative rubeotic eyes had rubeosis postoperatively (71%). Twenty-three percent of all eyes ended up with neovascular glaucoma.


Ophthalmology | 1988

A Prospective, Randomized, Clinical Trial of Heparin Therapy for Postoperative Intraocular Fibrin

Robert N. Johnson; George W. Blankenship

The authors undertook a study to investigate the ability of systemic or heparin supplementation of the vitrectomy infusion solution to prevent formation of postoperative intraocular fibrin membranes. A total of 73 eyes were randomized; 26 served as the control group, 23 received 10,000 IU of intravenous bolus of heparin, and 12 eyes each underwent the vitrectomy with an infusion solution containing 10 or 5 IU/cc of heparin. Intraoperative bleeding, postoperative bleeding, and postoperative fibrin formation were graded. A 10-IU/cc heparin infusion resulted in a statistically significant reduction in postoperative fibrin formation (P = 0.04) but increased intraoperative bleeding (P = 0.02). A trend toward reduced postoperative fibrin formation was noted in the intravenous heparin and 5 IU/cc infusion groups.

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David A. Quillen

Penn State Milton S. Hershey Medical Center

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Stuart L. Fine

University of Colorado Denver

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Brian C. Joondeph

Bascom Palmer Eye Institute

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