Management of the lens capsule during pars plana lensectomy.
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Cataract Extraction↗
Biomedical subjects
G W Abrams
Publications and source records attributed to G W Abrams.
Laser photocoagulation in the acute retinal necrosis syndrome.
Acute retinal necrosis (ARN) is a syndrome of fulminant necrotizing vaso-occlusive retinitis associated with a high incidence of retinal detachment due to retinal breaks and vitreous traction. We performed argon or krypton laser photo-coagulation to demarcate areas of active retinitis as prophylaxis against retinal detachment in five patients with ARN. Patients were concomitantly treated with antiviral agents, systemic steroids, and antiplatelet therapy. One patient required multiple additional treatments as retinal necrosis progressed. The retinas remained attached in all five patients over a mean follow-up period of 15 months. By creating a chorioretinal adhesion in areas of potential retinal break formation, laser photocoagulation may be an effective prophylaxis against retinal detachment in ARN.
Acute Disease↗
The management of subretinal gas following attempted pneumatic retinal reattachment.
Pneumatic retinopexy is a recently described procedure for treating retinal detachments with cryotherapy and intraocular gas injection, rather than scleral buckling. Prospective studies are underway to assess its safety and efficacy. One potential complication of this technique is persistent detachment due to subretinal gas. We report seven cases of subretinal gas following attempted pneumatic retinal reattachment. In all cases, multiple fish-egg gas bubbles were present following injection; some of these bubbles gained access to the subretinal space during the early postoperative period. The subretinal gas gave the detached retina a pearly, dome-shaped, refractive sheen. Three cases were managed by positioning the patients' heads to allow the subretinal gas to pass through the retinal break back into the vitreous cavity. One case underwent successful scleral buckling that closed the retinal break despite the presence of a small subretinal gas bubble. Three cases required vitrectomy, air-fluid exchange, and cryotherapy or endolaser treatment. In five of the seven eyes the retina was eventually reattached successfully.
Adult↗
Changing indications and techniques for vitrectomy in management of complications of diabetic retinopathy.
During the past two decades, the number of diabetic patients requiring vitrectomy for nonresolving vitreous hemorrhage has decreased four-fold, whereas there has been a substantial increase in diabetic patients with traction and combined traction/rhegmatogenous retinal detachment (RD) requiring surgery. Additional contemporary surgical indications are progressive fulminant neovascular proliferation, massive preretinal hemorrhage, massive fibrin response, and progressive retrolental fibrovascular proliferation. Surgical techniques for management of tractional detachments have evolved from circumscription of tractional epicenters to en bloc removal of all proliferative tissue.
Diabetic Retinopathy↗
Clinical results of titanium retinal tacks with pneumatic insertion.
We used titanium retinal tacks inserted with a pneumatic instrument for retinal fixation in 11 operative procedures in ten eyes with complicated retinal detachments. Titanium was selected for permanent implantation because of its documented biologic tolerance. No intraoperative or postoperative complications related to the tacks were encountered. Three tacks, one 0.7 mm in length and two 1.6 mm in length, became dislodged postoperatively; 50 permanently implanted tacks, each 1.6 mm in length, remained in place after a mean follow-up of five months. Retinal reattachment at the end of the follow-up period was achieved in eight eyes and useful visual function was obtained in three eyes. Titanium retinal tacks are useful when immediate retinal fixation is required either temporarily or permanently to prevent retraction and detachment of the retina until adjunctive diathermy, cryopexy, or photocoagulation becomes effective.
Adult↗
Penetrating keratoplasty after placement of a temporary keratoprosthesis during pars plana vitrectomy.
Five eyes of five patients with opaque corneas underwent penetrating keratoplasty after pars plana vitrectomy. In each case, the Landers-Foulks temporary keratoprosthesis provided visualization of the vitreous cavity and retina, allowed successful removal of hemorrhagic vitreous, and permitted retinal reattachment. Corneal grafts remained clear in two eyes; three grafts developed stromal edema. Useful postoperative vision was achieved in two eyes. However, proliferative vitreoretinopathy, postoperative hypotony, atrophia bulbi, and corneal edema resulted in poor vision in three eyes.
Adolescent↗
Management of postoperative suprachoroidal hemorrhage with continuous-infusion air pump.
Seven patients suffered delayed nonexpulsive suprachoroidal hemorrhages following filtration procedures. Six of seven eyes were aphakic, while the seventh had a subluxated lens associated with aniridia. In six of the seven cases, the hemorrhagic choroidal detachments completely filled the posterior segment, and visual acuity was reduced to light perception only. Surgical drainage of the hemorrhages was accomplished through one or two sclerotomies with simultaneous air insufflation of the eye through a limbal needle attached to a continuous-infusion air pump. With this technique, visual acuity was restored to a level equal to or better than the prefiltration acuity in five of seven patients. One patient suffered a slight decline in acuity from 20/60 to 20/100, and another patient's visual acuity declined from finger counting at 5 cm to hand motions.
Adult↗
Development of traction retinal detachments following intravitreal injections of retinal Muller and pigment epithelial cells.
We injected varying numbers of retinal Muller glia into the rabbit vitreous in an established model of traction retinal detachment. We used indirect ophthalmoscopy to observe the changes elicited during the following 1 month. Although the severity of the tractional changes increased with increasing numbers of the glial cells, the pathology produced stabilized within the 1st week of injury. Muller glia were less effective at eliciting retinal detachments than retinal pigment epithelial cells (RPE) or mixtures of glia and RPE. Intravitreal tissue membranes derived from the glia differed morphologically from those derived from RPE. The glial membranes had fewer fibroblast-like cells, synthesized less extracellular matrix, and showed lower intravitreal cell proliferation, as determined by 3H-thymidine radioautography. Our findings indicate that membranes composed only of Muller glial cells promote less severe retinal pathology than those membranes composed of RPE or mixed cell types.
Animals↗
Clinicopathologic results of vitreous surgery for epiretinal membranes in patients with combined retinal and retinal pigment epithelial hamartomas.
Two patients (a 44-year-old woman and a 26-year-old man) with progressive visual loss associated with macular combined retinal-retinal pigment epithelial hamartomas underwent pars plana vitrectomies with peeling of macular epiretinal membranes. Histopathologic findings for one of the membranes were similar to those in idiopathic or other secondary epiretinal membranes. Although the epiretinal membranes were satisfactorily removed, visual acuity improved in neither eye. Fluorescein angiography showed persistence of vascular tortuosity and leakage and cystoid macular edema after surgery in both cases. One eye developed a late postoperative operculated retinal tear which was successfully treated with cryopexy. The role of vitrectomy and membrane removal in cases of macular combined retinal-retinal pigment epithelial hamartomas appears to be limited.
Adult↗
The nonexpansile, equilibrated concentration of perfluoropropane gas in the eye.
Bubbles of 100% perfluoropropane (0.4 ml) were injected into the vitreous cavities of 31 New Zealand White rabbits. Gas bubbles were aspirated from eyes at six and 12 hours and at one, two, three, four, five, seven, nine, and 14 days, and were analyzed by gas chromatography. The nonexpansile concentration of perfluoropropane (found at maximum expansion of the gas bubble at four days) was approximately 12%. The gas bubble concentration equilibrated at seven days with a perfluoropropane concentration of approximately 10% with little change through 14 days. Using a similar protocol, we injected 0.56-ml bubbles of 100% perfluoropropane into the vitreous cavities of three owl monkeys. When sampled on day 4 for analysis by gas chromatography, results were comparable to the rabbit data. A 12% concentration of perfluoropropane should approximate the ideal composition of a gas mixture for a total fluid-gas exchange. This would achieve complete retinal tamponade without later compromise of intraocular pressure by further expansion.
Animals↗
Clearance of triamcinolone from vitreous.
The clearance of intravitreally injected triamcinolone acetonide was monitored by both indirect ophthalmoscopy and high-performance liquid chromatography (HPLC) and found to be more rapid than previously reported by others. Twenty-four rabbits were intravitreally injected in each eye with 0.4 mg of triamcinolone acetonide. Three rabbits each were sacrificed at intervals ranging from one hour to 46 days. The vitreous was then harvested and processed for HPLC analysis. Triamcinolone and the internal standard prednisolone were identified and quantitated by the use of HPLC, which was found to be both sensitive and specific for the steroids. The half-life as determined by HPLC was 1.6 days, the level at 13 days postinjection was 66 +/- 19 micrograms, and no drug was detectable by HPLC analysis at 21 days in five of six eyes. The intravitreal masses thought to be triamcinolone were clinically observable to an average of 23.3 days. The chromatographically determined clearance rate did not correlate well with clinical impressions based on indirect ophthalmoscopy.
Animals↗
Posttraumatic endophthalmitis.
Nineteen consecutive cases of culture-proved posttraumatic endophthalmitis occurred. Over an eight-year period, 19 (7.4%) of 257 patients with penetrating trauma had endophthalmitis develop, and 19 (31.1%) of 61 cases of endophthalmitis were due to trauma. Eleven (10.7%) of 103 patients with intraocular foreign bodies had endophthalmitis develop. Final visual acuity was 20/200 or better in eight (42.1%) of 19 and 20/30 or better in five (26.3%) of 19 cases of posttraumatic endophthalmitis. Organisms cultured were similar to those in the other types of endophthalmitis, except that Bacillus species were seen only in posttraumatic endophthalmitis (five [26.3%] of 19). Virulent organisms or retinal breaks or detachments seen at the time of primary repair indicated poor prognoses.
Adolescent↗
Prevention of lens opacification during diabetic vitrectomy.
Lensectomy at the time of vitrectomy on diabetic patients markedly increases the risk of postoperative neovascular glaucoma, and is to be avoided when possible. We conducted a randomized prospective double-blind trial to determine if the addition of supplemental glucose to BSS Plus intraocular irrigating solution would lessen or prevent intraoperative lens opacification. Ten subjects received BSS Plus (glucose = 100 mg/dl); five (50%) developed intraoperative lens changes which interfered with the surgeon's view (three to an extent necessitating lensectomy). Ten subjects received glucose fortified BSS Plus (glucose = 400 mg/dl); none developed intraoperative lens changes (P less than 0.03, Mann-Whitney Rank). There was no statistically significant difference between the two study groups with respect to preoperative lens changes, infusion fluid volume, operative time, patient age, duration of diabetes, fasting blood glucose level, hemoglobin A1 level or lens clarity 5 months after surgery. We conclude that glucose fortification of BSS Plus significantly reduces intraoperative lens opacification during diabetic vitrectomy.
Acetates↗
Reactive lymphoid hyperplasia of the uvea. A case with ultrasonographic and computed tomographic studies.
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Aged↗
Unilateral systemic lupus erythematosus retinopathy.
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Adult↗
Retinal periphlebitis as an early sign of bacterial endophthalmitis.
Retinal periphlebitis appeared as an early sign of bacterial endophthalmitis in three patients, a 36-year-old man with bilateral Terson's syndrome who underwent vitrectomy for dense vitreous hemorrhage, a 78-year-old woman who had had intracapsular cataract extraction and penetrating keratoplasty after repair of a wound leak and pars plana anterior membranectomy, and an 18-year-old man who suffered an accidental penetrating ocular injury. Staphylococcus organisms were recovered from vitreous samples in all three cases. Although recovery of useful vision is rare after postvitrectomy endophthalmitis, the first patient attained a final visual acuity of 20/50. The visual acuities of the second and third patients returned to 20/25 and 20/20 respectively. In an experimental primate (cynomolgus monkey) model of bacterial endophthalmitis, retinal periphlebitis developed early and closely resembled the clinical findings in humans. Histopathologic studies confirmed the presence of inflammatory cells that infiltrated the retinal venules.
Adolescent↗
Falsely extinguished bright-flash electroretinogram. Its association with dense vitreous hemorrhage.
Three patients with dense vitreous hemorrhages and nonrecordable bright-flash electroretinograms prior to vitrectomy all experienced great improvement in visual function and had recordable, though reduced-amplitude, electroretinograms soon after vitrectomy. None of the eyes had a major retinal detachment. The postoperative reduction in the electroretinogram in each case could be explained by the abnormality present. In common, the eyes required greater light than normal to elicit the electroretinograms post-operatively with clear media. While a damaged retina may have a nonrecordable electroretinogram in the presence of a preoperative dense vitreous hemorrhage, this may not preclude recovery of useful visual function following vitrectomy.
Adult↗
The effect of intraocular irrigating solutions on lens clarity in normal and diabetic rabbits.
We conducted a series of experiments on normal and diabetic rabbits to evaluate the effect of intraocular irrigating solutions on the lens. Lenticular clarity was studied in vivo in eyes undergoing vitreous cavity perfusions with various irrigating solutions. The clarity of isolated lenses incubated in these same solutions was also evaluated. In order to quantitate the cataractous changes observed, we measured the uptake of inulin (tagged with radioactive carbon) by isolated lenses. We found that balanced salt solution (BSS) and BSS Plus maintain excellent lens clarity in normal rabbits; that diabetic lenses are more likely to develop opacification than normal lenses, becoming cataractous when exposed to BSS Plus; and that adding supplemental glucose to BSS Plus allows this solution to maintain excellent lens clarity in diabetic rabbits.
Animals↗