Biomedical subjects
G Blankenship
Publications and source records attributed to G Blankenship.
Disciform choroidal melanoma.
BACKGROUND: The clinical and histopathologic findings in a hemorrhagic lesion involving the right macula of a 77-year-old man are presented. Clinical and fluorescein angiographic evaluation of the lesion led to a diagnosis of subretinal neovascular membrane secondary to age-related macular degeneration (AMD). The membrane was judged to be amenable to surgical excision and was excised. METHODS: Histopathologic and immunohistochemical studies were performed on the excised tissue. RESULTS: The lesion was a small, epithelioid cell choroidal melanoma. CONCLUSIONS: Newer surgical techniques for AMD may tend to preclude watchful waiting in the diagnosis of unusual hemorrhagic lesions in the macula, thereby increasing the importance of histopathologic examination of any tissue removed during such procedures.
Hypodermic stainless steel tacks and companion inserter designed for peripheral fixation of retina.
Mechanical fixation of the torn or cut edge of retina with 30-gauge hypodermic stainless steel tacks has been performed in 15 patients at the Bascom Palmer Eye Institute, Miami, and Miami Veterans Administration Medical Center with six to 18 months of follow-up. The companion tack inserter allows the surgeon to select an angle for the shaft of the tack in relation to the inserter to allow the tack to be driven perpendicularly into sclera even when the insertion is anterior to the equator. If residual detachment remains following fluid-gas exchange after preliminary placement of the retinal tacks, a given tack may be removed and reinserted to facilitate complete retinal reattachment. This utilitarian feature allows the surgeon to eliminate residual anteroposterior traction following complete membrane peeling by extending relaxing retinotomies and tacking the posterior cut edge of the retina securely between the ora serrata and the equator.
A prospective, randomized, clinical trial of heparin therapy for postoperative intraocular fibrin.
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.
Fluid-gas exchange and photocoagulation after vitrectomy. Indications, technique, and results.
We describe the indications, complications, and results of postvitrectomy fluid-gas exchange and laser photocoagulation for management of complicated vitreoretinal disease. Indications include proliferative vitreoretinopathy, vitreous opacities associated with proliferative diabetic retinopathy, giant retinal tear, recurrent rhegmatogenous retinal detachment, and trauma. Eyes treated with 50% sulfur hexafluoride gas rather than sterile air demonstrated a higher intraocular pressure on the first postexchange day, which was not a significant source of disease. There was no statistically significant difference in retinal reattachment between eyes treated with gas and those treated with air. Fluid-gas exchange in eyes with partial or total retinal detachment resulted in total or partial retinal reattachment, with the macula attached in 82% of cases within the first 48 hours following exchange. Final reattachment rate, with a mean follow-up of 8.9 months (range, six to 36 months), was 55%. In eyes with proliferative vitreoretinopathy, the combination of postoperative argon or krypton laser photocoagulation with fluid-gas exchange was associated with a final reattachment rate of 75%. Postoperative fluid-gas exchange and photocoagulation appear to be safe and effective advances in the treatment of complicated vitreoretinal diseases requiring vitrectomy.
Retinopathy risk factor regression after laser panretinal photocoagulation for proliferative diabetic retinopathy.
Fifty eyes of patients with proliferative diabetic retinopathy were followed at frequent intervals to determine the rapidity and stability of retinopathy risk factor regression after argon laser panretinal photocoagulation. Retinopathy risk factors regress rapidly after laser photocoagulation. The incidence of eyes at high risk for severe visual loss (eyes with 3 or more retinopathy risk factors) decreased from 100% prior to treatment to 28% three weeks after treatment. The early response to treatment was a good prognostic indicator of longer term results. Seventy-two percent of eyes which improved from a high- to a low-risk category by three weeks continued to remain at low risk at six months. Sixty-four percent of eyes which failed to improve to a low-risk category by three weeks continued to remain at high risk at six months. The early response to laser panretinal ablation may be used to predict longer-term results.
Surgical techniques for selected giant retinal tears.
Based on clinical experience, improved methods for treating giant retinal tears with an inverted retinal flap are described. In all cases a broad encircling scleral buckle is used in conjunction with a broad zone of peripheral chorioretinal adhesion produced by cryotherapy and, often, supplemented by postoperative photocoagulation. This virtually eliminates recurrent retinal detachment from an anterior location, if the retinal flap can be properly unfolded and the retina is initially reattached. Vitrectomy is done in all these cases, and an intraocular bubble is used to unfold and reposition the retinal flap during or after surgery. If the retinal flap is especially stiff or foreshortened, special techniques are used to incarcerate the edge of the retinal flap in the pars plana or the peripheral choroid, or transvitreal suturing techniques are used to secure the edge of the retinal flap to the eyewall before fluid-gas exchange is performed. This insures proper unfolding of the flap by the intraocular bubble. Applying retinal cryotherapy before performing the vitrectomy seems to reduce the occurrence of postoperative proliferative vitreoretinopathy (PVR), perhaps because retinal pigment epithelial cells in the vitreous cavity are removed during vitrectomy. Frequent, detailed examination during the first three weeks after surgery and use of postoperative photocoagulation to supplement the cryotherapy seem to prevent recurrent detachment from anterior leakage of subretinal fluid beneath the retinal flap or through other anterior retinal breaks.
Regression of diabetic rubeosis iridis following successful surgical reattachment of the retina by vitrectomy.
The relationship between successful surgical reattachment of the retina following diabetic vitrectomy and regression of preoperative rubeosis iridis was investigated. Seventy-nine (9.2%) of 850 diabetic cases undergoing vitrectomy had both preoperative iris rubeosis and retinal detachment. The iris could be adequately evaluated and the retina could be visualized after surgery in 36 cases. Regression of the rubeosis iridis occurred after surgery in 16 (76%) of 21 eyes in which the retina was reattached successfully. Only four (27%) of 15 eyes had regression of rubeosis iridis when the retina was not reattached completely. Retention of the lens also correlated with regression of rubeosis iridis. Regression occurred in 10 (55%) of 18 cases in which the lens was not removed, 13 (28.2%) of 46 eyes in which lensectomy was combined with vitrectomy, and none of eight previously aphakic eyes. Although the combination of preoperative retinal detachment and rubeosis iridis is associated with a worsened prognosis, successful reattachment of the retina and retention of the lens favorably influence later regression of preoperative rubeosis iridis.
Complications of retrobulbar marcaine injection.
Respiratory arrest following retrobulbar marcaine injection has been described with increasing frequency. The following case reports document the occurrence and provide some insight to its management. A possible solution to the problem is suggested.
Vitrectomy for proliferative diabetic retinopathy associated with vitreous hemorrhage.
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.
Acute disc swelling in juvenile diabetes. Clinical profile and natural history of 12 cases.
Acute disc swelling was documented in 21 eyes of 12 patients with long-standing juvenile diabetes. All but one patient were in the second or third decade of life, with a 13-year average duration of diabetes. Seventeen eyes had initial acuity of 20/50 or better, including nine eyes with 20/25 or better; disc swelling was asymptomatic in six eyes. Simultaneous bilateral disc swelling occurred in seven patients. With no specific therapy, vision generally recovered to normal levels within a few weeks, but a few patients retained arcuate, nerve fiber bundle, field defects and optic atrophy. There was no positive correlation with the degree of diabetic retinopathy, and disc swelling did not seem to be a harbinger of progressive retinopathy or proliferation at the nerve head. Disc swelling in juvenile diabetics represents a distinct clinical entity that must be distinguished from other causes of acquired nerve head elevation, especially papilledema of increased intracranial pressure.
Panretinal photocoagulation influence on virectomy results for complications of diabetic retinopathy.
Despite panretinal photocoagulation (PRP), some diabetic eyes develop complications that are correctable with vitrectomy. The results of vitrectomy performed on 80 eyes having pre-vitrectomy PRP are compared with 402 eyes without photocoagulation. The preoperative findings and operative procedures were almost identical, except the PRP cases had a slightly higher incidence of preoperative iris rubeosis and traction macular detachments, and more surgical membrane peeling. Six months after vitrectomy, the PRP eyes had slightly better visual acuities and fewer detached maculas, but were otherwise almost identical to the non-photocoagulated eyes. There was no evidence that pre-vitrectomy PRP prevents postoperative iris rubeosis.
Preoperative iris rubeosis and diabetic vitrectomy results.
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The lens and pars plana vitrectomy for diabetic retinopathy complications.
Major cataracts developed in 28 of 168 eyes during the six months after pars plana vitrectomy for complications of diabetic retinopathy. In only ten of these cases did the cataract influence the visual results. The visual acuities of the phakic and aphakic eyes six months after vitrectomy were almost identical. Rubeosis iridis occurred in 23% of the phakic eyes and 45% of the aphakic eyes, with the difference being related to the loss in the aphakic eyes of a protective barrier lens quality. However, this same barrier quality increased the incidence of postoperative opaque vitreous hemorrhage from 8% of the aphakic eyes to 21% of the phakic eyes. Corneal epithelial edema at surgery occurred in 55% of those eyes that had lens removal combined with vitrectomy, but in only 36% of those that retained their lenses, and the difference was caused by the increase in operative time and procedure.
Pars plana vitrectomy for diabetic retinopathy. A report of 8 years' experience.
Vitrectomies have been performed on 299 cases of dense diabetic vitreous hemorrhages and been followed for 6 months. A successful visual result was obtained in 61% of the cases. The vitreous remained clear in 71% of the cases, and the maculas were attached in 66% of the cases 6 months following surgery. 168 cases of traction macular detachments underwent vitrectomy, and had 6-month follow-up examinations. Significant visual improvement was obtained in 26% of the cases, with stabilization of the preoparative vision in an additional 37% of the cases. The vitreous cavity was clear in at least 64% of the cases, and the macula attached in at least 52% of the cases. 86 cases had both dense vitreous hemorrhages and traction macular detachments, and had 6-month postoperative examinations, with significant visual improvement having been obtained in 31% of the cases, and stabilization of the preoperative vision in an additional 33% of the cases. The postoperative vitreous cavities were clear in 59% of the cases, and the maculas attached in at least 45% of the cases.
Pars plana vitrectomy for the management of sever diabetic retinopathy.
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.