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Biomedical subjects

G W Blankenship

Publications and source records attributed to G W Blankenship.

At least 19 recordsLinked to original sources
PubMed1998

Diabetic retinopathy.

Nonproliferative diabetic retinopathy may cause visual loss when associated with macular edema or macular ischemia (secondary to retinal capillary nonperfusion). Proliferative diabetic retinopathy may cause severe visual loss if complicated by vitreous hemorrhage or traction detachment of the macula. Patients with diabetes benefit from collaboration between the internist and ophthalmologist. Tighter control of blood glucose levels and lower blood pressure reduce the risk of progression of diabetic retinopathy. Regular dilated eye examinations and appropriate intervention with laser or vitrectomy surgery help to preserve vision in patients with established macular edema or proliferative diabetic retinopathy.

Blindness↗
PubMed1996

Central serous chorioretinopathy in women.

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.

Adrenal Cortex Hormones↗
PubMed1995

Vitrectomy for complications of proliferative diabetic retinopathy. Functional outcomes.

PURPOSE: To quantitate the effect of diabetic vitrectomy on each patient's visual system and function. METHODS: The anatomic and visual acuity outcomes of diabetic vitrectomy among three surgeons at one institution over a 4-year time interval were studied. Outcome parameters describing the visual system function were defined and applied to quantitate the effect on visual system disability. RESULTS: The anatomic and visual success rates and prognostic factors in the cohort of 213 patients by standard statistical analysis were similar to previous studies. The study eye was the eye with better vision in 68 (32%) patients at the conclusion of the study, and vision was equal to the fellow eye in 35 (16%) patients. The mean impairment of the visual system by the American Medical Association Guidelines for Disability was reduced from 61% preoperatively to 50% postoperatively. The factor associated with greatest degree of reduction of impairment of the visual system was a previtrectomy diagnosis of vitreous hemorrhage. There was at least a one-step improvement of visual system function in 65 (31%) patients. CONCLUSIONS: Vitrectomy for complications of severe proliferative diabetic retinopathy is especially valuable in improving the patient's overall visual function.

Diabetic Retinopathy↗
PubMed1993

Intraocular pressure fluctuations during scleral buckling surgery.

PURPOSE: The purposes of this study are to measure real-time intraocular pressure (IOP) during scleral buckling and to determine the effects of elevated IOPs on ocular perfusion. PATIENTS AND METHODS: A standard 4-mm, 20-gauge infusion cannula was inserted through the pars plana, connected to a standard hemodynamic monitoring unit with an electronic pressure transducer, and calibrated. The authors measured real-time IOP in 20 eyes undergoing scleral buckling surgery for primary rhegmatogenous retinal detachments and determined the IOP required to close the central retinal artery. Pressure measurements were read from the monitor videoscreen intraoperatively and from a continuous paper tracing postoperatively. RESULTS: The patients ranged in age from 24 to 88 years (mean, 59.7 years). The highest IOP elevations occurred during scleral depression and cryopexy, ranging up to 210 mmHg (mean, 116 mmHg). Pressures at which the central retinal artery closed ranged from 48 to 110 mmHg (mean, 79.2 mmHg). Manipulations of the globes caused IOPs greater than the central retinal artery perfusion pressures in 13 of the 20 patients. The duration of pressures in excess of the central retinal artery perfusion pressure ranged from 6 to 402 seconds (mean, 118.8 seconds). There were no intraoperative or postoperative complications from the infusion cannula. CONCLUSIONS: Conventional scleral buckling surgery causes wide fluctuations in IOP and may impair ocular perfusion. Additional studies are needed to determine the long-term consequences of these pressure elevations.

Adult↗
PubMed1991

Evaluation of a single intravitreal injection of dexamethasone phosphate in vitrectomy surgery for diabetic retinopathy complications.

For evaluation of the efficacy and toxicity of dexamethasone phosphate after pars plana vitrectomy, 27 randomly selected eyes received 0.8 mg intravitreal dexamethasone phosphate and 30 control eyes did not receive this injection. No signs of dexamethasone phosphate toxicity were observed during 6 months of follow-up evaluations. Visual acuities of 20/40 or better were obtained in 26% of the dexamethasone-treated group and 33% of the control group, and those of 20/200 or better were obtained in 74% of the dexamethasone-treated eyes and 73% of the control eyes. Moderate anterior chamber flare or fibrin formation occurred in only 15% of the dexamethasone-treated eyes but in 27% of the control eyes one day after surgery. Lens changes occurred equally in both groups. None of the eyes in either group developed substantial intraocular proliferation or membranes following surgery.

Adult↗
PubMed1991

Fifteen-year argon laser and xenon photocoagulation results of Bascom Palmer Eye Institute's patients participating in the diabetic retinopathy study.

Fifteen years after panretinal photocoagulation in the Diabetic Retinopathy Study, 86 (57%) patients had died, 14 (9%) could not be located, and 51 (34%) of 151 patients were examined to determine the long-term treatment effects. Of the eyes randomized to photocoagulation only 1 (5%) of 19 argon-treated and 1 (3%) of 32 xenon-treated eyes had received additional laser treatment, but 8 argon-treated and 7 xenon-treated eyes had had cataract removal. Eleven (58%) of the initially argon-treated and 13 (41%) of the initially xenon-treated eyes had 20/40 or better acuity, and 18 (95%) of the initially argon-treated and 26 (82%) of the initially xenon-treated eyes had 20/200 or better acuity. Of the control eyes 17 (33%) had 20/40 or better, and 30 (58%) had 20/200 or better acuity. Argon and xenon panretinal photocoagulation for diabetic retinopathy provide good results for at least 15 years.

Adult↗
PubMed1990

The effect of short versus long exposure times of argon laser panretinal photocoagulation on proliferative diabetic retinopathy.

We performed a randomized clinical trial comparing short-duration (0.1 s) with long-duration (0.5 s) blue-green argon laser burns to deliver panretinal photocoagulation (PRP) in eyes suffering from proliferative diabetic retinopathy with high risk characteristics. We studied 19 eyes in the 0.1-s group and 24 eyes in the 0.5-s group for 6 months. Two or more lines of acuity were lost by 20% of the 0.1-s PRP eyes, but by only 8% of the 0.5-s PRP eyes; New or increased vitreous hemorrhages occurred in 30% of the 0.1-s PRP eyes, but in only 16% of the 0.5-s PRP eyes; New or increased traction retinal detachments did not occur in the 0.1-s PRP eyes, but occurred in 16% of the 0.5-s PRP eyes. There was complete disc neovascular regression in 85% of the 0.1-s PRP eyes and 81% of the 0.5-s PRP eyes. These trends were not statistically significant.

Adolescent↗
PubMed1990

Management options for retinal detachment in the presence of a posteriorly dislocated intraocular lens.

Six consecutive cases of retinal detachment occurring in the presence of a posteriorly dislocated intraocular lens were managed between 1978 and 1988. In three cases, a standard scleral buckling procedure was performed with successful retinal reattachment, leaving the dislocated implant in the inferior formed vitreous. In two cases, the implant was removed through the pars plana at the time of pars plana vitrectomy, fluid/gas exchange, and scleral buckling procedure. In the remaining case, the intraocular lens was repositioned with scleral fixation sutures after pars plana vitrectomy, fluid/gas exchange, and scleral buckling. All cases achieved and maintained retinal reattachment with visual improvement. Recommendations for management are discussed.

Adult↗
PubMed1989

The surgical management of giant retinal tears with the cannulated extrusion needle.

In 18 eyes of 17 patients, we treated retinal detachment caused by a giant retinal tear by unfolding and repositioning the retina with a cannulated extrusion needle. After pars plana vitrectomy, a fluid-gas exchange was performed with the patient in the supine position. Using the cannulated extrusion needle to drain subretinal fluid posterior to the giant retinal tear, the retinal flap was manipulated into the correct anatomic position. With this technique, 18 of 18 eyes with retinal detachment caused by a giant retinal tear were successfully reattached intraoperatively. Although eight of these eyes subsequently redetached and required additional surgical procedures, 16 of 18 eyes remain attached with a mean follow-up of 11 months.

Adult↗
PubMed1989

Posterior chamber intraocular lens insertion during pars plana lensectomy and vitrectomy for complications of proliferative diabetic retinopathy.

We inserted posterior chamber lenses into 21 eyes with complications of diabetic retinopathy upon completion of pars plana lensectomy and vitrectomy in a single session. After the original surgery, two eyes developed retinal detachments and underwent vitrectomy revisions with scleral buckling, one eye had a fluid-gas exchange for residual vitreous cavity blood, one eye had supplemental laser treatment, and one eye had intraocular antibiotics for endophthalmitis. Six months later, postoperative vision was better in 16 of the 21 eyes (76%), the same in four eyes (19%), and worse in one eye (5%). In 16 eyes visual acuity was 20/200 or better, and in six eyes it was 20/40 or better postoperatively. Decreased vision was caused by preexisting macular disease; two eyes had corneal edema with iris neovascularization associated with residual retinal detachment. The procedure and lenses were well tolerated and provided good pseudophakic vision.

Adult↗