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J F Korobelnik

Publications and source records attributed to J F Korobelnik.

At least 19 recordsLinked to original sources
PubMed1999

e-PTFE as scleral buckling episcleral implants: an experimental and histopathologic study.

To investigate the effects of focal implantation of expanded polytetrafluoroethylene (e-PTFE) episcleral implants (i.e., explants or exoplants) on surrounding ocular tissues, an experimental and histopathological study was performed. Twenty-seven Fauve de Bourgogne rabbits eyes were implanted for a period of 3-11 months with oval-shaped e-PTFE episcleral implants. A newly formed capsule constantly encased the implants. Affected by the only two severe complications observed, 2 eyes had an endocapsular acute inflammation and could not be included in the study. Finally, 25 eyes were studied histopathologically. Neither intrusion nor extrusion of episcleral implants was observed. Other changes were related to implant characteristics. The inner surface of the capsule was often covered with numerous giant cells attesting to a foreign-body granuloma developed against the irregular outline of the episcleral implants. The porosity of the material was closely related to its surface irregularity, and also allowed its colonization by a fibrovascular and inflammatory tissue mainly in its peripheral layers. Under episcleral implants, sclera was both thinned and invaginated. Expanded PTFE hydrophobia was the other factor that might have suscitated granuloma. These microscopic changes are in contrast with an overall good apparent experimental tolerance to the material. However, additional studies on the long term behavior of this material would be helpful.

Animals↗
PubMed1999

Effect of autologous platelet concentrate in surgery for idiopathic macular hole: results of a multicenter, double-masked, randomized trial. Platelets in Macular Hole Surgery Group.

OBJECTIVE: To evaluate prospectively the efficacy and safety of autologous platelet concentrate (APC) as an adjuvant in surgery for idiopathic macular hole. DESIGN: Multicenter, double-masked, randomized clinical trial. SETTING: Four university-based ophthalmology clinics. PARTICIPANTS: One hundred ten patients with stage 3 or 4 idiopathic full-thickness macular holes of less than 3 years' duration were randomized (53 eyes to the platelet group and 57 eyes to the control group). INTERVENTIONS: Standardized macular hole surgery versus surgery combined with injection of an APC. In all cases, the procedure consisted of three-port pars plana vitrectomy, posterior hyaloid separation, and nonexpansile fluid-gas exchange. After the fluid-gas exchange, patients were randomized to receive either injection of an APC or no adjunctive treatment. After surgery, patients were positioned face down for 12 days. Platelet counts showed that the concentrates contained a mean of 96.106 platelets (range, 82-102). MAIN OUTCOME MEASURES: Anatomic and functional evaluations were performed at 1, 3, and 6 months after surgery in a double-masked fashion by an independent observer. The main outcome was reapposition of the edge of the macular hole 1 month after surgery. Secondary outcomes were anatomic status at 3 and 6 months, changes in Early Treatment Diabetic Retinopathy Study score, and complications. RESULTS: One month after surgery, the anatomic success rate in the platelet group was 52 of 53 (98%; 95% confidence interval, 0.90-1.00) versus 47 of 57 (82%; 95% confidence interval, 0.70-0.91) in the control group (P = 0.009, Fisher's exact test; relative risk, 0.11; 95% confidence interval, 0.01-0.81). Visual acuity was not significantly different between the two groups at any timepoint. There were no complications specifically attributable to the platelet injection. CONCLUSION: Injection of APC improved significantly the anatomic success rate of surgery for idiopathic macular holes of less than 3 years' duration, but postoperative visual acuity of the platelet group was not statistically different from the control group.

Aged↗
PubMed1999

Scleral and episcleral histological changes related to encircling explants in 20 eyes.

PURPOSE: To investigate scleral and episcleral histological alterations induced by encircling explants used in scleral buckling procedures. METHODS: We performed a histopathological study of 20 enucleated eyes after failure of retinal detachment surgery including encircling scleral buckle. RESULTS: Nonabsorbable materials were encapsulated and often gave rise to a limited scleral invagination. The inner capsular surface was regular in 10 silicone explants, it was partially covered with hydrogel fragments and a granulomatous foreign body giant cell reaction in 8 hydrogel explants. One Arruga thread was encased in fibrosis and a catgut circle showed no encapsulation. Other changes were mostly related to the long-standing retinal detachment: peripheral anterior synechiae, anterior uveal effusion, persistent retinal detachment, retinal gliosis, retinal atrophy, retinal breaks, and silicone oil droplets. CONCLUSION: All nonabsorbable explants underwent encapsulation and prompted scleral invagination. A granulomatous reaction accompanied hydrogel fragmentation. The long term fragmentation impact on implanted eyes remains unknown.

Adult↗
PubMed1999

Experimental encircling scleral buckle with silicone and hydrogel: histopathologic and comparative study of 26 rabbit eyes.

PURPOSE: To analyze histologic changes induced by encircling elements, rabbit eyes were implanted with two different biomaterials. MATERIALS AND METHODS: Thirty-seven rabbit eyes (37 rabbits) were implanted with encircling oval episcleral elements. Two materials were used: silicone sponge and hydrogel. The animals were killed and their eyes collected for histopathology. Of 37 eyes, 26 that were implanted for 111 to 455 days were selected for the study. RESULTS: In 26 eyes, scleral buckling was visible. Scleral examination showed a regular erosion under the buckle, mainly with silicone. All explants were surrounded by a fibrous capsule, which was smooth and regular with silicone. With hydrogel, fragmentation was observed with a giant cell reaction. Capsule thickness increased, mainly with hydrogel. CONCLUSION: Fragmentation affected segmental or circumferential hydrogel explants. As in silicone explants, the capsule surface was normal when the hydrogel surface was respected. The fragmentation mechanism remains unclear.

Animals↗
PubMed1999

TPA-assisted vitrectomy for proliferative diabetic retinopathy: results of a double-masked, multicenter trial.

OBJECTIVE: Some complications of vitrectomy are related to adherence of the vitreous body to the retina. We studied whether these complications could be decreased by injecting a proteolytic enzyme, tissue plasminogen activator (TPA), at the beginning of surgery to aid separation of the vitreous from the retina. METHODS: Fifty-six patients receiving surgery for complications of proliferative diabetic retinopathy were divided into two groups in this prospective, randomized, double-blind study. Group I patients received 25 microg of intravitreal TPA in buffered salt solution (BSS) 15 minutes before vitrectomy. Group II received BSS alone. Postoperative follow-up lasted up to 3 months. The major criteria for comparison were the number of perioperative iatrogenic tears, the gain in visual acuity, and the reattachment rate of tractional retinal detachments. RESULTS: No difference was found between the two groups for the principal indicators or for complications. CONCLUSION: In proliferative diabetic retinopathy, the use of 25 microg of TPA by intravitreal injection 15 minutes before vitrectomy does not improve the results. No specific complications of the method were noted. The failure can be attributed to a too-short delay between TPA injection and beginning of surgery, an insufficient dose, or an insufficient quantity of plasminogen in the vitreous at the beginning of the intervention.

Diabetic Retinopathy↗
PubMed1999

[Histological changes related to scleral buckling for treatment of retinal detachment].

Treatment of retinal detachment frequently uses biocompatible materials to obtain scleral buckling. These materials are not devoid of consequences on surrounding tissues. In 3 eyes enucleated for failure of surgical treatment using scleral buckling materials, the changes prompted by episcleral implants could be observed. The sclera underwent both an inversion of its curvature and a reduction of its thickness under the material, as well as an encapsulation of the material was observed. While a silicone sponge was used in part to encircle one of these eyes, its capsular inner surface was regular and smooth. In contrast, hydrogel implants used in the three eyes showed a peripheral fragmentation prompting in two of them a typical foreign body giant cell granulomatous reaction. Changes in scleral curvature and scleral thinning were observed reflecting the consequences of the buckling procedure. The capsule formation occurred as it does for any nonabsorbable matérial implanted in tissues. Degradation and fragmentation of the hydrogel material suscitated a granuloma in response to fragments. These hydrogel specific changes should be recognized on microscopic examination of slides of either capsule or eyes previously in contact with this implanted material. They attested of the instability of hydrogel after implantation.

Aged↗
PubMed1998

Encapsulation of scleral buckling materials. A study of sixty specimens.

OBJECTIVE: The purpose of the study was to obtain information on the encapsulation of two nonabsorbable biomaterials (silicone and hydrogel) used as explants in scleral buckling in retinal detachment surgery. DESIGN: The study design was a histopathologic study on a cohort of capsule fractions and complete eyes. PARTICIPANTS: Fifty-nine patients participated in this study, in which 60 specimens, including 37 hydrogel and 21 silicone capsule specimens as well as 2 whole eyes, were gathered. There were no control subjects. INTERVENTION: The capsule specimens were obtained from eyes operated on previously for scleral buckling for retinal detachment. The two whole eyes were enucleated. All specimens were studied with routine optic microscopy. MAIN OUTCOME MEASURES: Patient characteristics, type of scleral buckling, and number of operations performed were analyzed. Histologically, the capsular structure, its interface with the explant, and its different components also were studied. Remnants of the buckling material also were investigated. RESULTS: There were 45 male and 14 female patients, with a mean age of 49 years. Histologically, capsule specimens had a fibrous matrix with fibroblasts and few inflammatory cells. Eighteen (48.6%) of 37 hydrogel capsule specimens displayed hydrogel fragments surrounded by a foreign body giant cell granuloma in 16 cases. CONCLUSION: Nonabsorbable materials undergo encapsulation after implantation on the eye surface. Giant cell granuloma was observed in some hydrogel capsule specimens in relation to hydrogel fragmentation. The exact origin of this fragmentation remains unknown.

Adolescent↗
PubMed1998

Silicone oil removal combined with macular pucker dissection: a retrospective review of 14 cases.

PURPOSE: Silicone oil must be removed from the eye to avoid late complications after the surgical management of proliferative vitreoretinopathy (PVR). Macular pucker, frequently observed after retinal detachment surgery, is responsible for visual impairment. The safety of a procedure combining epimacular membrane peeling and silicone oil removal was retrospectively evaluated. METHODS: Fourteen eyes that had previously undergone vitrectomy and silicone oil tamponade for rhegmatogenous retinal detachment with severe PVR, penetrating or blunt trauma, and intraocular foreign bodies were included. Silicone oil tamponade was maintained for a mean period of 30 weeks (range, 12-108 weeks). The removal of silicone oil was combined with the peeling of an epimacular membrane. RESULTS: Mean follow-up after silicone oil removal was 86 weeks (range, 13-234 weeks). The final retinal reattachment rate was 78%. Macular pucker recurred in one eye after a 24-month period. Best-corrected visual acuity improved two lines or more in eight eyes (57%) and reached 20/200 or better in eight eyes (57%) at last follow-up. CONCLUSION: Macular pucker dissection and silicone oil removal can be safely combined. This single procedure can obviate the need for further surgery in eyes that have already undergone multiple operations and allows good visual recovery.

Adolescent↗
PubMed1998

[Surgical treatment of retrofoveal choroid neovascularization in multifocal choroiditis].

BACKGROUND: Surgical removal of subfoveal choroidal neovascularization allows visual improvement, especially in young patients. METHODS: Three eyes of 3 patients were prospectively studied. Subfoveal choroidal neovascularization was related to presumed ocular histoplasmosis syndrome. The surgical procedure included vitrectomy, surgical excision of the neovascular membrane, and air tamponnade. RESULTS: Follow-up was 6, 12 and 20 months. Vision improved in 2 eyes. In one case, recurrent extrafoveal neovascularization was treated with laser photocoagulation. DISCUSSION: Surgery seems to be an alternative to photocoagulation in subfoveal choroidal neovascularization in presumed ocular histoplasmosis.

Adult↗
PubMed1998

[Value of posterior capsulorrhexis during combined phacoemulsification and silicone oil removal].

Combined surgery with silicone oil removal, phacoemulsification and intraocular lens implantation was retrospectively evaluated in 9 eyes of 9 patients. Visual acuity was better after surgery in 7 eyes, and 8 eyes did not required further posterior capsulotomy during follow-up (10 months). In 2 eyes post-op intraocular inflammation was observed. Redetachment of the retina occurred in one eye. Posterior capsulorrhexis can be done during cataract surgery and silicone oil removal in a vitrectomised eye, without inducing direct complications.

Adult↗
PubMed1997

Management of viral retinitis-associated retinal detachment in AIDS.

We retrospectively reviewed the results of surgery in 27 cases of retinal detachment related to viral necrotising retinitis in acquired immune deficiency syndrome (AIDS). Vitrectomy and silicone oil tamponade were performed in all cases. Scleral buckling was applied to 9 eyes. Silicone oil was left in the eye in all cases. Mean follow-up period was 13 weeks. Post-operative flattening of the retina at the posterior pole was achieved in 89% of the eyes. Anatomical results were not related to the intraoperative use of an encircling procedure. Visual acuity improved by 2 Snellen lines or more in 40% of cases and 67% of the eyes retained a post-operative ambulatory vision. Phacosclerosis and optic atrophy developed in 29% and 22% of cases, respectively. Vitrectomy and silicone oil tamponade without scleral buckling are effective in the management of retinitis-associated retinal detachments. This procedure is short and can be performed under local anaesthesia.

AIDS-Related Opportunistic Infections↗
PubMed1997

Choroidal neovascularization complicating epiretinal membrane removal.

PURPOSE: Surgical removal of epiretinal membranes generally leads to anatomic and functional improvement. Main complications include cataract, retinal breaks and detachment. We describe the onset of a juxtafoveal choroidal neovascularization 2 years after surgery of an epiretinal membrane. METHODS: The neovascular membrane was treated by argon laser photocoagulation. RESULTS: Complete obliteration of the neovascularization was obtained resulting in functional improvement. CONCLUSIONS: Although rare, choroidal neovascularization as a complication of epiretinal membrane surgery must be suspected in case of poor visual outcome or relapse of symptoms.

Adult↗
PubMed1997

Management of silicone-induced cataract in AIDS patients treated for viral retinitis-associated retinal detachment.

BACKGROUND AND OBJECTIVE: To evaluate the outcome of cataract surgery for patients with acquired immunodeficiency syndrome (AIDS) who underwent vitrectomy and silicone tamponade for viral retinitis-associated retinal detachment. PATIENTS AND METHODS: The authors retrospectively reviewed the data of five AIDS patients (five eyes) who had cataract within a mean period of 4 months following vitrectomy and silicone oil tamponade for viral retinitis-associated retinal detachment. Phacoemulsification and implantation of a poly-methylmethacrylate posterior chamber intraocular lens were performed. The mean postoperative follow-up was 3 months. RESULTS: Neither silicone oil loss nor retinal redetachment were reported postoperatively. Visual acuity improved in two eyes and remained unchanged in one eye. Total blindness occurred in two eyes. CONCLUSION: Although cataract surgery in these eyes is a relative easy procedure and does not interfere with the retinal status, visual outcome remains poor because of possible postoperative optic atrophy.

AIDS-Related Opportunistic Infections↗
PubMed1997

[Ring recurrence of ciliary body melanoma after proton-beam therapy].

A malignant ciliary body melanoma was treated by proton-beam irradiation. Ring-shaped recurrence with extraocular extension appeared thirty-six months later and required enucleation. Histologic study revealed a predominant epithelioid cell type tumor, flattened in previously treated area. Proton-beam irradiation efficiency depends on clinical evaluation, which remains questioned in ciliary body locations where circumferential extension could be misevaluated.

Aged↗