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Biomedical subjects

W E Benson

Publications and source records attributed to W E Benson.

At least 19 recordsLinked to original sources

Reoperation following diabetic vitrectomy.

A review of 484 consecutive eyes that were undergoing an initial pars plana vitrectomy for the sequelae of proliferative diabetic retinopathy disclosed that 41 eyes (8.5%) required one or more additional vitrectomy operations. The primary causes for reoperation included rhegmatogenous retinal detachment in 18 (44%) of the 41 eyes, recurrent vitreous hemorrhage in 21 eyes (51%), and glaucoma in two eyes (5%). The visual prognosis was worse in the group with rhegmatogenous retinal detachment, with 10 (56%) of 18 eyes progressing to no light perception (P = .003). Severe preretinal and subretinal fibrous proliferation, as demonstrated histopathologically, accounted in large part for the poor result. The preretinal membrane formation appeared to occur secondary to a combination of diabetic extraretinal vascular growth and proliferative vitreoretinopathy. Among the total group of 41 eyes that required subsequent surgery, the retina eventually remained detached in 18 eyes (44%), and phthisis bulbi occurred in 13 eyes (32%). Rubeosis iridis developed in 17 (94%) of 18 eyes in which the retina remained detached.

Adult

Long-term stability and visual outcome after favorable initial response of proliferative diabetic retinopathy to panretinal photocoagulation.

The authors assessed the relationship between early objective response to panretinal photocoagulation (PRP) and the subsequent long-term visual outcome in 59 eyes of 59 consecutive patients who developed proliferative diabetic retinopathy while under the care of a retinal specialist. Thirty five eyes (59%) had regression of high-risk retinopathy characteristics within 3 months of treatment. Eighteen of these eyes (52%) had a final visual acuity of 20/20 or better with a mean follow-up of more than 4 years. Only 2 of the 24 nonresponder eyes (8%) had visual acuity of 20/20 or better. Thirteen of the responder eyes (37%) sustained a delayed vitreous hemorrhage, which was usually self-limited. Three responders underwent vitrectomy with excellent visual results. The authors conclude that the beneficial effect of PRP on visual outcome is directly related to the regression of retinopathy risk factors and that the long-term visual prognosis in high-risk eyes manifesting a favorable initial response to PRP is excellent.

Adult

Inadvertent globe perforation during retrobulbar and peribulbar anesthesia. Patient characteristics, surgical management, and visual outcome.

The authors report a series of 20 eyes from 20 patients in whom inadvertent perforation of the globe occurred during local anesthesia for ocular surgery. Perforation resulted from retrobulbar anesthesia in 18 eyes and from peribulbar anesthesia in 2 eyes. Nine (45%) of 20 eyes had an axial length greater than or equal to 26.00 mm. Combining this figure with axial length data for the general population and estimates for the risk of globe perforation during local anesthesia yields an approximate incidence of perforation in eyes with axial length greater than or equal to 26.00 mm of 1 in 140 injections. Proliferative vitreoretinopathy (PVR) developed in 8 of the 20 eyes (40%) in this series. Overall, 15 (75%) of the 20 eyes were successfully repaired, and, in five eyes (25%), the final visual acuity was 20/70 or better.

Adult

Retrobulbar bupivacaine irrigation for postoperative pain after scleral buckling surgery. A prospective study.

The authors conducted a prospective, randomized, double-masked clinical trial to determine if retrobulbar irrigation with bupivacaine hydrochloride 0.75% (Marcaine) has an effect on postoperative pain after scleral buckling surgery. Fifty consecutive patients undergoing scleral buckling under general anesthesia were randomized to receive either bupivacaine or balanced salt solution as a retrobulbar irrigation at the end of their retinal detachment procedure. Of the 25 patients who received bupivacaine, only three (12%) required parenteral pain relief in the first 24 hours after surgery. This was statistically significant when compared with the 18 (72%) of 25 patients requiring parenteral pain relief in the placebo group (P less than 0.0001). In addition, when questioned about their perception of the degree of postoperative pain, patients in the control group rated their level of pain as significantly more severe than did patients in the bupivacaine group. The authors conclude that retrobulbar irrigation with bupivacaine is a safe and effective way to achieve postoperative pain relief after surgery for scleral buckling.

Adolescent

Treatment of foveal pigment epithelial detachments with contiguous extrafoveal choroidal neovascular membranes.

Fourteen eyes of 14 patients who had subfoveal retinal pigment epithelial detachments and extrafoveal contiguous choroidal neovascular membranes associated with age-related macular degeneration underwent laser photo-coagulation treatment directed solely to their choroidal neovascular membrane. In eight of 14 eyes (57%), photocoagulation treatment resulted in closure of the choroidal neovascular membrane with subsequent collapse of the pigment epithelial detachment. Six of the eight eyes also had visual improvement. In six of 14 eyes (43%), the neovascular membrane eventually progressed into the fovea with resultant visual loss. The results of our study suggest that photocoagulation of extrafoveal choroidal neovascular membranes associated with foveal detachments of the retinal pigment epithelium may preserve and even improve visual function in affected patients.

Aged

Iris neovascularization after central retinal artery obstruction despite previous panretinal photocoagulation for diabetic retinopathy.

Five consecutive patients with proliferative diabetic retinopathy who were treated successfully with panretinal photocoagulation subsequently developed a central retinal artery obstruction. Iris neovascularization developed in the affected eye within one to three months after the obstruction in four of the five patients despite the previous laser treatment. Additional retinal ischemia, as occurs in central retinal artery obstruction, appears to promote marked iris neovascularization in a large percentage of patients, even when successful photocoagulation for proliferative retinopathy has been previously administered.

Adult

Basic fibroblast growth factor levels in the vitreous of patients with proliferative diabetic retinopathy.

A two-site enzyme-linked immunosorbent assay was used to quantitate levels of basic fibroblast growth factor in the vitreous from 36 patients undergoing vitrectomy for a variety of retinal conditions, including proliferative diabetic retinopathy, macular pucker, and retinal detachment with and without proliferative vitreoretinopathy. Basic fibroblast growth factor levels ranged from undetectable to 52 ng/mL. In patients with proliferative diabetic retinopathy, basic fibroblast growth factor levels were greater than or equal to 30 ng/mL in 8 of 17 specimens. Of the 8 patients with elevated basic fibroblast growth factor levels, 6 had evidence of active proliferative disease (ie, neovascularization of the disc or iris), whereas in the patients who had undetectable levels only 2 of 9 had evidence of neovascularization of disc and none had neovascularization of the iris. In the rhegmatogenous retinal detachment group, 2 of 10 eyes had elevated basic fibroblast growth factor levels, while none in the macular pucker group had elevated levels. Our study documents increased levels of basic fibroblast growth factor in vitreous specimens from patients with proliferative diabetic retinopathy, particularly those with active proliferative retinopathy. The role of basic fibroblast growth factor in the pathogenesis of various retinal disease entities is discussed.

Diabetic Retinopathy

Rapidly progressive acute retinal necrosis secondary to herpes simplex virus, type 1.

A systemically healthy 22-year-old man presented with unilateral acute retinal necrosis (ARN) that featured diffuse retinal whitening throughout the posterior retina, exudative retinal detachment, and a visual acuity of no light perception. Diagnostic vitrectomy revealed necrotic retinal cells containing intranuclear inclusions visible with light microscopy. On electron microscopy, viral particles consistent with a herpes family virus were detected. Culture of the vitrectomy specimen showed herpes simplex, type 1 (HSV 1) and rising convalescent serum ELISA titers to HSV 1 confirmed a recent infection. This case of ARN is unusual for its severity, early macular involvement, and development of exudative retinal detachment. In addition, it represents one of the few reported cases in which HSV 1 has been confirmed by both vitreous culture and serum titers as the etiologic agent. A review of the literature suggests that posterior segment inflammatory conditions secondary to HSV 1 can be associated with exudative retinal detachment, a clinical finding that may help differentiate such conditions from other infectious causes of chorioretinitis.

Adult

Visual prognosis correlated with the presence of internal-limiting membrane in histopathologic specimens obtained from epiretinal membrane surgery.

Forty-one patients with a unilateral, macular epiretinal membrane (ERM) underwent pars plana vitrectomy and membrane peeling to improve the visual acuity. The authors retrospectively reviewed the histopathology of the vitrectomy specimen in each instance to determine whether the presence of internal-limiting membrane (ILM) had an adverse effect on visual acuity. Eleven specimens contained long segment of ILM, as determined by light microscopy. With a minimum of 6 months of follow-up, none of these 11 eyes achieved a visual acuity of better than 20/60. Of 30 eyes that did not have ILM present, 41% achieved a visual acuity of 20/60 or better. Overall, 29% of the eyes in the entire series achieved 20/60 or better visual acuity. The difference between the group with ILM versus that without ILM was statistically significant (P = 0.01). The presence of long segments of ILM within the histopathologic specimen after vitreous surgery for removal of a macular ERM appears to indicate a less favorable visual outcome.

Follow-Up Studies

Extracapsular cataract extraction, posterior chamber lens insertion, and pars plana vitrectomy in one operation.

Extracapsular cataract extraction (ECCE), placement of a posterior chamber intraocular lens (PC IOL), and pars plana vitrectomy were combined in a single operation in 24 patients. Sixteen of these, 11 of whom are diabetic, have had 6 months or more of follow-up. In all cases, excellent visualization of the posterior segment was obtained, and the surgical objectives were achieved. No diabetic patient without preoperative neovascularization of the iris had this complication later. The advantages and disadvantages of alternative techniques are discussed.

Adult

Re-operation following pars plana vitrectomy for the sequelae of proliferative diabetic retinopathy.

A review of 306 eyes undergoing pars plana vitrectomy for the complications of proliferative diabetic retinopathy revealed that 26 (8.5%) required a second vitrectomy operation. Among the eyes that required repeat vitrectomy, the eventual visual acuity ranged from 20/20 to 20/400 in 35% and was no light perception in 31%. Reasons for subsequent surgery included recurrent vitreous hemorrhage in 54% of eyes, retinal detachment in 42% and neovascular glaucoma in 4%. Twelve eyes (46%) remained with a permanent retinal detachment despite attempts at surgical repair, and eleven of these twelve eyes subsequently developed rubeosis iridis.

Adult

Use of sodium hyaluronate for the repair of giant retinal tears.

Sodium hyaluronate (Healon) was used in conjunction with pars plana vitrectomy and scleral buckling to manage unilateral giant retinal tears of 180 degrees or more with severe folding in six consecutive cases. In each instance the retina was successfully flattened, and five of the six have remained so for at least one year. The technique enables the surgeon to unroll a retinal flap that is markedly inverted on itself and oppose it to the underlying retinal pigment epithelium.

Adolescent

Combined extracapsular cataract extraction, posterior chamber lens implantation and pars plana vitrectomy.

The authors describe the technique of extracapsular cataract extraction and posterior chamber lens implantation in conjunction with pars plana vitrectomy. In persons with the sequelae of proliferative diabetic retinopathy and retinal branch vein obstruction, as well as those with rhegmatogenous retinal detachment, the procedure enables visual rehabilitation with one operation and seemingly no increase in morbidity.

Adult

Massive suprachoroidal hemorrhage. Follow-up and outcome of 30 cases.

The authors studied the records of 30 patients who suffered a massive suprachoroidal hemorrhage during cataract surgery. Immediate development of a retinal detachment (RD) is a very bad prognostic sign. In none of 12 such cases could the retina be reattached. Retinal complications developed in five of six patients who had vitreous incarceration and who did not have vitrectomy as opposed to only one of seven who underwent vitrectomy along with drainage of the hemorrhage. If vitreous is incarcerated in the cataract incision, drainage of the hemorrhage without vitrectomy is a dangerous procedure.

Adult

Complications of vitrectomy for non-clearing vitreous hemorrhage in diabetic patients.

One hundred consecutive patients with proliferative diabetic retinopathy underwent vitrectomy for nonclearing vitreous hemorrhage. Eighty-two had significantly improved vision; nine had no improvement in vision; and nine had complications which resulted in permanent loss of vision. Only three eyes lost vision because of neovascular glaucoma. Our results indicate that with improved surgical techniques, the incidence of vitrectomy complications is decreasing.

Diabetic Retinopathy

Retinal injury and detachment in boxers.

From March 1983 to October 1985, the members of the Retina Service of the Wills Eye Hospital treated nine boxers with traumatic retinal injuries. Eight of these had retinal detachments requiring scleral buckling procedures. The ninth had a large tear without subretinal fluid that was treated with cryotherapy alone. In this article the authors describe the type and location of retinal injury, initial and follow-up treatment, and associated ocular findings and the mechanism of injury.

Adult