Retinal detachment in Marfan's syndrome.
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Adult↗
Biomedical subjects
F I Tolentino
Publications and source records attributed to F I Tolentino.
Complications of surgery for subfoveal choroidal neovascularization.
Advancing surgical techniques have made the surgical excision of subfoveal CNV possible in all cases. However, serious surgical complications lead to a limited visual outcome in many cases. The major complications that cause poor visual outcome are related to poor case selection and include injury to the RPE, with secondary atrophy of the choriocapillaris and damage to the neurosensory retina, and a high rate of persistent or recurrent CNV. Patients with POHS have localized disease of the RPE-Bruch's membrane complex and typically have CNV growing between the RPE and neurosensory retina (type 2 CNV). These patients have the best visual prognosis postoperatively because of the potential for maintaining native RPE beneath the fovea. Patients with AMD typically have CNV growing beneath the RPE (type I CNV). These patients are poor surgical candidates because the surgical excision of type I CNV is almost always associated with débridement of native subfoveal RPE and a poor visual outcome. Presently, all surgical studies have been retrospective and are characterized by limited follow-up. Therefore, whether surgical excision of subfoveal CNV is beneficial as compared to mere observation is uncertain. A large, randomized, prospective study currently is being performed. These Submacular Surgery Trials will attempt to determine whether these surgical procedures are more efficacious than observation and whether the benefits outweight the risks of surgery in these patients.
Choroidal Neovascularization↗
Surgical management of subretinal hemorrhage.
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Animals↗
Surgical management of choroidal neovascular membranes.
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Choroid↗
13-cis-retinoic acid in silicone-fluorosilicone copolymer oil in a rabbit model of proliferative vitreoretinopathy.
The purpose of this study was to evaluate the effect of 13-cis-Retinoic Acid (RA) in Silicone-Fluorosilicone Copolymer Oil (SiFO) in a rabbit model of proliferative vitreoretinopathy (PVR). Rabbits underwent gas-compression vitrectomy. During gas-SiFO exchange, group 1 was injected with 1 ml (10 microg ml-1) 13-cis-RA in SiFO, group 2 with 1.5 ml (9 microg 1.5 ml-1) all-trans-RA in SiFO, group 3 with 1 ml SiFO alone, and group 4 with balanced salt solution (BSS). Groups 1-4 were also injected with 0.1 ml suspension of fibroblasts (75,000 0.1 ml-1) and 0.05 ml platelet rich plasma (70,000 0.1 ml-1), and were observed for 4 weeks. Group 5 was injected with SiFO alone, group 6 with 1 ml (10 microg ml-1) 13-cis-RA in SiFO, group 7 with 1.5 ml (9 microg 1.5 ml-1) all-trans-RA in SiFO, and group 8 with BSS. After 4 weeks, groups 5-7 underwent SiFO-BSS exchange. ERG and histopathology were performed to test for retinal toxicity in groups 5-8. The incidence of traction retinal detachment at 4 weeks was: group 1, 42.9%; group 2, 36.4%; group 3, 87.5%; and group 4, 88.9%. A significant difference in the incidence of PVR was noted between treated eyes (groups 1 and 2) and control eyes (groups 3 and 4) at 2, 3, and 4 weeks (P<0.05). No significant difference in the incidence of PVR was found between groups 1 and 2 during the same observation periods. ERG and histopathological studies showed no differences between the treated and the control fellow eyes (group 5-7) after 4 weeks. 13-cis-RA in SiFO (10 microg ml-1) is as effective as all-trans-RA in SiFO (9 microg 1.5 ml-1) in controlling the incidence of PVR when used for short term retinal tamponade and does not appear to be associated with retinal toxicity.
Animals↗
The complications of perfluoropropane gas use in complex retinal detachments.
BACKGROUND: Perfluoropropane (C3F8) is a valuable adjunct in the management of complex rhegmatogenous retinal detachments, and it has become the most commonly used perfluorocarbon gas. However, there have been few large reports about its complications. This retrospective study was undertaken to evaluate the complications of the use of perfluoropropane gas. METHODS: Perfluoropropane gas was used in the repair of a complex retinal detachment in 157 consecutive eyes. Only eyes that had a follow-up of 6 months or greater were included. Any eyes that had undergone previous vitrectomy and vitreous substitution with gas or silicone oil were excluded. RESULTS: Gas-induced lens opacities developed in 26 (67%) phakic eyes; transient increased intraocular pressure developed postoperatively in 50 (32%) eyes; a transient fibrinous, pupillary membrane developed in 20 (13%) eyes; and a flat anterior chamber developed in 10 (6%) eyes. CONCLUSIONS: Scleral buckle placement and increased gas concentration were found to be risk factors for the development of increased intraocular pressure. Proliferative diabetic retinopathy was associated with a higher development of lens opacities and pupillary membranes. No major complications were associated with the use of C3F8.
Adolescent↗
Retinoic acid in silicone and silicone-fluorosilicone copolymer oils in a rabbit model of proliferative vitreoretinopathy.
PURPOSE: The authors evaluated the effect of retinoic acid (RA) in silicone oil (SiO) and in silicone-fluorosilicone (SiFO) copolymer oil in a new rabbit model of proliferative vitreoretinopathy (PVR). METHODS: To create the PVR model, three groups of rabbits were administered vitreous injections of approximately 100,000 homologous fibroblasts, 75,000 platelet-rich plasma (PRP), and fibroblasts + PRP, respectively. These rabbits were followed up ophthalmoscopically and histopathologically for as long as 2 months. Five additional groups of rabbits underwent gas-compression vitrectomy in one eye. Four days later, group 1 was administered intravitreous RA in SiFO (9 micrograms/ml) with approximately 150,000 fibroblasts and 70,000 PRP. Group 3 was administered the same amount of fibroblasts and PRP as group 1 with RA in SiO (9 micrograms/ml). Groups 2, 4, and 5 were administered the same amount of fibroblasts and PRP as groups 1 and 3 with 1 ml of SiFO, SiO, or balanced salt solution only, respectively. To evaluate RA toxicity, RA was injected in SiO (15 and 20 micrograms/ml) and RA in SiFO (10 micrograms/ml). RESULTS: All eyes that were administered fibroblasts or PRP developed vitreous membranes, but those with PRP alone did not develop proliferative changes or retinal detachment; fibroblasts alone produced proliferative changes and retinal detachment after 2 to 3 weeks; fibroblasts + PRP produced similar changes within 3 days of injection. Retinoic acid (15 micrograms/ml) in SiO and RA (10 micrograms/ml) in SiFO was well tolerated. Retinal atrophic changes were found in eyes with 20 micrograms/ml RA in SiO. The retinal detachment rate was lower (P < 0.05) in the eyes that were administered fibroblasts + PRP and RA than in the controls. Significant differences were found in the degrees of PVR among the groups. CONCLUSIONS: RA could be useful in PVR treated with SiO or for eyes treated intraoperatively with heavier-than-water SiFO when it is used as a short-term retinal tamponade.
Animals↗
Silicone oil as a delivery vehicle for BCNU in rabbit proliferative vitreoretinopathy.
The antiproliferative properties of a single intravitreous injection of BCNU [carmustine; 1,3-bis(2 chloroethyl)-1-nitrosourea] dissolved in 1 ml of medical grade, 1,000-centistoke silicone oil were evaluated in a rabbit model of proliferative vitreoretinopathy (PVR). 10 micrograms and 15 micrograms of BCNU in 1 ml silicone oil resulted in a 46% and 27% reduction in the incidence of retinal detachments, respectively. Chi-square tests showed a significant statistical difference (P < 0.05) between the control and treated groups. However, histopathologic examination of the eyes injected with BCNU and silicone oil indicated some retinal disorganization even at the lower therapeutic levels. With a therapeutic index of < 1.0, BCNU in silicone oil has a low margin of safety for treatment of PVR. Nevertheless, this study demonstrates that silicone oil when used for retinal tamponade in PVR may be the vehicle for delivery of a lipophilic antiproliferative agent.
Animals↗
Antiproliferative effect of retinoic acid in intravitreous silicone oil in an animal model of proliferative vitreoretinopathy.
PURPOSE: To evaluate, in vitro, the solubility and stability of all-trans RA in silicone oil (SiO) and, in vivo, the stability and the antiproliferative effect of all-trans RA in SiO on an experimental model of PVR. METHODS: The solubility and stability of RA in SiO, in vitro and in vivo, were evaluated by HPLC. Rabbits underwent unilateral gas-compression vitrectomy and gas-SiO exchange. Rabbits received 10 micrograms (n = 17), 5 micrograms (n = 11), and 2 micrograms (n = 9) of all-trans RA in SiO, and SiO only (n = 12). All rabbits received an intravitreous injection of 150,000 fibroblasts. RESULTS: RA is stable in SiO in vitro, but some isomerization from all-trans to 13-cis was observed under light exposure. In vivo, after 1 week, trace amounts of RA in SiO were observed in the controls and in the experimental animals, suggesting a steady state between the release of RA from the SiO and from the retina to the SiO. The rate of fractional retinal detachment was significantly lower in the animals that received 10 and 5 micrograms of RA than in the controls (P < 0.05). No statistical differences were found between the eyes treated with 10 and 5 micrograms of RA. Eyes that received 2 micrograms of RA showed no difference from the control group. CONCLUSIONS: The in vivo data suggest that retinoic acid might be useful as an antiproliferative agent in human eyes.
Animals↗
Long-term complications of the MAI hydrogel intrascleral buckling implant.
Seven cases in which long-term complications developed from swelling of the MAI hydrogel intrascleral buckling implant are reported herein. Micro-Fourier transform infrared spectroscopic analysis of two recovered implants demonstrated the occurrence of chemical changes leading to increased swelling. Clinical problems with the implants appeared 7 to 11 years after surgery, suggesting the need for periodic, long-term follow-up. It is possible that the present-day MIRAgel implant, which has the same chemical composition as the MAI implant, may require similar precautions.
Adolescent↗
The refractive index of Vitreon.
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Animals↗
Best's macular dystrophy with a macular hole.
The occurrence of a macular hole with Best's dystrophy is an extremely rare finding with only one reported case in the literature. We wish to report two cases with typical Best's dystrophy in one eye and a macular hole in the contralateral eye. In one case the Pattern Reversal VER (PVER) was also recorded and graphed as an amplitude-check size function curve. The PVER changes in this case were grossly subnormal in both the eyes, suggesting a significant degree of bilateral macular impairment. This implies that a significant amount of functional impairment occurs at the vitelliform stage itself, though how this stage progresses to a macular hole is unclear.
Adult↗
Vitreous hemorrhage after closed vitrectomy for proliferative diabetic retinopathy.
The authors reviewed the medical records of 191 patients (232 eyes) who underwent closed vitrectomy for complications of diabetic retinopathy to evaluate the clinical picture of postvitrectomy hemorrhage (PVH). One hundred thirty-nine eyes (59.9%) had at least one episode of PVH (average, 1.5 per eye) that was variable in onset, not associated with a known cause in four fifths, with no noted source in two thirds, and severe in three fourths of the cases. Using logistic regression statistical analyses, the factors significantly associated with decreased incidence of PVH include older age of patient (P = 0.0004), long duration of surgery (P = 0.0002), and poor preoperative vision (P = 0.05). Of the 139 eyes with PVH, 65 (47%) had spontaneous clearing in an average of 11.3 weeks, 53 (38%) required repeat surgery, and 21 (15%) were inoperable, lost to follow-up, or refused reoperation. Postvitrectomy hemorrhage did not significantly influence the final visual outcome.
Adult↗
Diabetic retinopathy: pathogenesis and management of complications.
Diabetic retinopathy, one of the ocular complications of the metabolic imbalance that characterize diabetes mellitus is a major cause of irreversible blindness. This article reviews the concepts of the pathogenesis of this complex disease. The management of this blinding disease is multifaceted and should be based on the sound understanding of the pathophysiologic mechanisms involved. The rationale, techniques, results and complications of the different treatment modalities including glycemic control, laser photocoagulation and vitrectomy are discussed.
Adolescent↗
Reevaluation of corneal complications after closed vitrectomy.
Corneal complications after closed vitrectomy were analyzed in patients treated by the same surgeon from January 1980 through December 1986. Of 428 eyes (400 patients), 64 (15%) had corneal complications, 58 (13.6%) had epithelial defects, and 12 (2.8%) had corneal edema. Among 206 diabetic eyes, 41 (19.9%) had corneal complications. Of 222 nondiabetic eyes, only 23 (10.4%) showed complications. Multiple regression analysis of possible contributing factors was performed. Diabetes, intraoperative lensectomy, and history of vitreous surgery were related significantly to the occurrence of all corneal complications combined. Our series showed a significantly decreased complication rate when compared with a previous study. Improved preoperative surgical preparation and intraoperative technique to minimize corneal trauma may have accounted for the decrease.
Cornea↗
Anterior proliferative vitreoretinopathy. Clinicopathologic, light microscopic, and ultrastructural findings.
Proliferative vitreoretinopathy (PVR) involving the posterior and equatorial retina is an established clinicopathologic entity. Clinically, a similar process, anterior PVR (APVR), results in anterior dragging of the peripheral retina by membranes which connect to the ciliary body or iris and cause circumferentially and radially fixed retinal folds. The pathology of APVR, however, has not been reported. The authors describe pathologic findings in 28 cases of APVR and ultrastructural pathologic findings in 6 surgical APVR specimens. Anterior PVR was frequently associated with retinal detachment (RD) repair (96%) and trauma (38%). Residual vitreous at the vitreous base virtually always provided a scaffold for membranes containing proliferating cells and deposited extracellular matrix. Major components of APVR membranes were fibrovascular tissue (71%), pigment epithelial cells (43%), fibrous and corneal stromal ingrowth (32%), and glial proliferation (18%). Because of its anterior location, APVR membranes also incorporated ciliary epithelium and corneal endothelium. Contraction of APVR membranes caused anterior retinal displacement and detachment in anatomic configurations corresponding to narrow and wide peripheral troughs. The authors' findings indicate that APVR is a distinctive clinicopathologic entity which may complicate rhegmatogenous RD and its repair.
Adult↗
Extraction of retinol and cholesterol by intraocular silicone oils.
According to their solubility parameters, retinol and its derivatives, as well as cholesterol and other lipophilic substances, are predicted to dissolve in intraocular silicone and fluorosilicone oils. Calf retinas were extracted in vitro with these oils and the oils then analyzed spectrophotometrically. The following levels were found after extraction for 4 and 48 hours, respectively: for retinol, silicone oil, 0.5 and 3.7 micrograms/ml, and fluorosilicone oil, 0.5 and 3.3 micrograms/ml; for cholesterol, silicone oil, 0.5 and 6.4 micrograms/ml, and fluorosilicone oil, 0.8 and 3.7 micrograms/ml. In in vivo experiments, intraocular oils were removed from rabbit eyes at 4 days to 10 weeks after injection. The retinol levels were 1.7 to 11.4 micrograms/ml in silicone oil and 2.4 to 7.3 micrograms/ml in fluorosilicone oil; the cholesterol levels were 2.7 to 12.6 micrograms/ml in silicone oil and 7.5 to 15.6 micrograms/ml in fluorosilicone oil. Fluorosilicone and silicone oils (1000 cs) removed from human eyes at 7.3 and 102.0 weeks postoperatively had a retinol content of 5.4 and 2.9 micrograms/ml, respectively. Silicone oil of 1000 cs removed from a patient 51 weeks postoperatively and silicone oil of 12,500 cs removed 96 weeks postoperatively gave reaction characteristics for cholesterol, 230 and 99 micrograms/ml, respectively.
Animals↗
BCNU in silicone oil in proliferative vitreoretinopathy: I. Solubility, stability (in vitro and in vivo), and antiproliferative (in vitro) studies.
Various pharmacologic agents have been tried to control proliferative vitreoretinopathy (PVR). However, most are water soluble and cannot be used with silicone oil (SO), a tamponade agent also used in PVR management. We evaluated a lipophilic, antiproliferative drug, BCNU, in regard to its solubility and stability in SO, its release from SO into an aqueous solution, and its effect on cell cultures. BCNU is soluble in SO (peak concentration in micrograms/ml 1020, 750, and 294 at 37 degrees C, 21 degrees C, and 4 degrees C, respectively), and stable (half-life = 6.7 weeks at 37 degrees C, 17.9 weeks at 21 degrees C). At 4 degrees C, no significant decrease in concentration up to eight weeks was noted. BCNU is released from SO to water (partition coefficient = 10.28 +/- 2.16). Its median inhibitory doses (ID50) on bovine retinal pigment epithelial (RPE), rabbit RPE, and subconjunctival fibroblast cells are 13, 1.9, and 15.6 micrograms/ml, respectively. BCNU may be a useful pharmacologic tool to control PVR.
Animals↗