Primary transpupillary thermotherapy for small choroidal melanomas.

AIMS: To determine visual and anatomic outcomes following transpupillary thermotherapy (TTT) as a primary treatment for small choroidal malignant melanomas. METHODS: 20 patients with small choroidal melanomas who underwent primary TTT at our institution were retrospectively reviewed. Patients with choroidal melanomas posterior to the equator with a basal diameter less than 12 mm and thickness less than 3.5 mm were included if the lesion had documented growth or clinical risk factors for growth. RESULTS: Thirteen women and seven men (mean age: 65 years, range: 41-85 years) underwent TTT. The mean preoperative tumour thickness was 1.81 mm (range: 0.78-3.40 mm). The mean follow-up time after TTT was 44.6 months (range: 11-108 months, median: 47.5 months). After a mean of 2.15 primary TTT sessions (range: 1-4), tumour regression without recurrence was attained in 11 (55%) of 20 cases. Five of the nine remaining tumours with recurrence were successfully treated with additional TTT. One patient declined further TTT and underwent enucleation. Three other tumours had recurrence after repeat TTT. The mean time to recurrence after initial TTT was 20.8 months (range: 8-37 months). The mean time to recurrence after repeat TTT was 35 months (range: 5-69 months). There was no tumour-related metastasis or death. CONCLUSIONS: Tumours treated with TTT have significant recurrence rates. Although tumour control may ultimately be achieved with TTT, close monitoring of these tumours is necessary, since repeat TTT or alternative therapies may be required.

Anterior proliferative vitreoretinopathy in the silicone study. Silicone Study Report Number 10.

BACKGROUND: As part of the design of the Silicone Study, a new classification of proliferative vitreoretinopathy (PVR) was developed that distinguishes the different types of contraction found in PVR. In contrast to the original Retina Society system that emphasized the post-equatorial retinal pathology (posterior PVR), the Silicone Study classification system included the characteristic types of contraction found in both the equatorial region and the pre-equatorial retina and vitreous base (anterior PVR). METHODS: The authors contrast (1) preoperative and intraoperative findings and (2) vision and anatomic outcomes in the cohort of anterior PVR eyes with the cohort of posterior-only PVR eyes. For the cohort of eyes randomized to perfluoropropane gas (C3F8) or silicone oil, the authors carry out univariate and multivariate analyses to assess the predictive value of baseline and intraoperative parameters on vision and anatomic outcome. RESULTS: Anterior PVR was present in 321 eyes (79%) and was more prevalent in eyes that had undergone an unsuccessful vitrectomy before study entry than in eyes that underwent a primary vitrectomy for PVR (88% versus 73%; P < 0.001). Compared with eyes that had posterior PVR at the preoperative examination, eyes that had anterior PVR tended to (1) be graded (Retina Society classification system) as D-1 or worse (86% versus 49%; P < 0.0001), (2) have worse (< 2/200) visual acuity (93% versus 86%; P = 0.003), (3) have more hypotony (24% versus 11%; P = 0.03), more edema (8% versus 2%; P = 0.04), more aqueous flare (P = 0.02), more macular pucker (69% versus 52%; P = 0.005), and more intravitreal contraction (21% versus 6%; P = 0.002). When compared with eyes that had anterior PVR, eyes with posterior PVR had a better outcome at the 6-month postoperative examination: complete attachment of the retina (76% versus 62%; P = 0.04), visual acuity of 5/200 or better (64% versus 45%; P = 0.006), and normal intraocular pressure (86% versus 71%; P = 0.04). For eyes with anterior PVR, significant predictors of poor (< 5/200) visual acuity were a preoperative PVR grade D-1 or worse and the use of C3F8 gas as the intraocular tamponade. CONCLUSION: The Silicone Study classification of anterior PVR permits greater specificity in characterizing PVR and is prognostic of anatomic and vision outcome. Eyes with anterior PVR and clinically significant posterior PVR changes had a better visual prognosis if silicone oil was used. With the current understanding of the pathoanatomy of anterior PVR and the recent development of new surgical techniques, the incidence of anterior PVR in eyes that previously underwent vitrectomy may decline, and the prognosis in eyes with anterior PVR may improve.

Macular pucker after successful surgery for proliferative vitreoretinopathy. Silicone Study Report 8.

BACKGROUND: The prevalence of postoperative macular pucker and the factors associated with its development after successful surgery for proliferative vitreoretinopathy (PVR) using silicone oil or gas tamponade are unknown. METHODS: The postoperative status of the macula was determined by reviewing the photographs of 336 eyes taken 6 months after randomization. Two hundred eleven eyes with attached maculas were identified and analyzed to determine the prevalence of macular pucker after silicone oil and gas tamponades in eyes without (group 1) and with (group 2) previous vitrectomy surgery. Data obtained at baseline, from the primary study surgery, and from subsequent examinations and repeat surgeries during a follow-up period of 6 months were analyzed for factors associated with postoperative macular pucker. RESULTS: The 6-month-point prevalence rate of postoperative macular pucker was 15% (32 of 211 eyes). Ten of the 32 eyes were new cases of macular pucker. The authors were unable to document a difference in the 6-month-point prevalence of postoperative macular pucker between group 1 and group 2 eyes (13% versus 18%) or between eyes randomized to gas versus silicone oil (19% versus 12%). Postoperative pucker was three times as likely to develop in aphakic/pseudophakic eyes compared with phakic eyes (P = 0.02). Focal contraction posteriorly causing starfolds, and intravitreal contraction involving the vitreous base or vitreous cavity, were significantly less prevalent in eyes with postoperative macular pucker (P < 0.05). Large (> or = 2 disc diameters) retinal breaks (P = 0.04) were associated significantly with postoperative macular pucker (P = 0.04). The authors were unable to document an association between postoperative macular pucker and the type of adhesive modality used or the extent of its application. Postoperative visual acuity was significantly better if the macula was not puckered (P < 0.01). CONCLUSIONS: The occurrence of macular pucker after successful surgery for retinal detachments complicated by severe PVR is not influenced by the choice of intraocular tamponade. Certain preoperative factors may be associated with postoperative macular pucker.

Color matching and the Stiles-Crawford effect in observers with early age-related macular changes.

We studied the color-match-area effect and the Stiles-Crawford effect in 10 observers with age-related macular changes. Observers were graded on a scale of I to IV according to the Sarks classification, which correlates fundus appearance and visual acuity with the severity of postmortem histological changes in Bruch's membrane. Observers in group II showed subtle abnormalities of color matching; those in groups III and IV showed more-severe abnormalities. The Stiles-Crawford effect was abnormal in 9 of 10 eyes tested. Only one observer showed a Stiles-Crawford effect that had a well-defined peak near the center of the pupil and a near-normal bandpass. The results suggest that early age-related changes visible in the fundus can be revealed by psychophysical tests of photoreceptor architecture.

Intraocular injection of silicone oil for experimental proliferative vitreoretinopathy.

We evaluated the effect of intraocular silicone oil as an internal tamponade on an animal model of proliferative vitreoretinopathy. Lensectomy and vitrectomy were performed on two groups of pigmented rabbits. Twenty-five rabbit eyes then had 1,000 centistokes' viscosity silicone oil injected into the vitreous cavity; 20 control eyes received balanced salt solution. Fourteen days later, each eye was injected with homologous fibroblasts (ten eyes with 100,000 cells, 25 eyes with 250,000 cells, and ten eyes with 750,000 cells). All membranes that developed after the cell injections in both experimental and control eyes produced traction retinal detachment. The character of the membranes formed and the timing of the traction retinal detachment were the same for both groups. In an active phase of experimental proliferation, the internal tamponade of silicone oil is insufficient to keep the retina in place.

Specular microscopy in pars plana vitrectomy.

A prospective study of endothelial cell loss following pars plana vitrectomy and pars plana vitrectomy with lensectomy was performed in 21 eyes. Fifteen diabetic patients had either vitrectomy alone or vitrectomy with lensectomy. Six nondiabetic eyes were also included in this study. The average cell loss was between 2.3% and 3.9% in all cases. This difference was not statistically significant from the preoperative measurements of endothelial cell counts. These data suggest that pars plana vitrectomy does not result in significant endothelial cell loss, especially when eyes remain phakic or when the anterior capsule is maintained until the end of the case.

Lensectomy-vitrectomy in chronic uveitis.

Cataract extraction in patients with chronic uveitis may be hazardous, although recent studies have indicated an improvement in prognosis using lensectomy-vitrectomy techniques in selected cases of uveitic cataracts. The results of lensectomy-vitrectomy in 12 eyes with uveitic cataract are reported. All patients had improvement in vision. No significant "flare-up" of the underlying uveitis occurred. The importance of extensive preoperative evaluation is emphasized. The major cause of decreased acuity postoperatively was persistent cystoid macular edema, a complication of chronic inflammation.

Lensectomy-vitrectomy in chronic uveitis.

Cataract extraction in patients with chronic uveitis may be hazardous. Recent studies have indicated an improvement in prognosis using lensectomy-vitrectomy techniques in selected cases of uveitic cataracts. The results of lensectomy-vitrectomy in 12 cases of uveitic cataract are reported. All patients had improvement in vision. No significant "flare-up" of the underlying uveitis was found and no patients deteriorated. The importance of extensive preoperative evaluation is emphasized. The major cause of decreased acuity after operation was persistent cystoid macular edema, a complication of chronic inflammation.

Branch vein occlusion. Retinal neovascularization outside the involved segment.

Three hundred sixty-six cases of branch vein occlusion entered within the multicenter Branch Vein Occlusion Randomized Clinical Trial have been reviewed. Four cases that developed retinal neovascularization outside of the retinal area involved with the occlusion have been documented by photography and fluorescein angiography.

The role of cellular proliferation in an experimental model of massive periretinal proliferation.

Transplantation of from 10,000 to 750,000 autologous and homologous dermal fibroblasts into the vitreous cavity of rabbit eyes resulted in identical clinical findings leading to massive periretinal proliferation. A dose-response relationship between the number of cells injected and the extent of retinal traction that developed was established. The second phase of the experiment evaluated the effects of formalin and cobalt irradiation on the fibroblasts' ability to cause traction retinal detachment. Cell proliferation or the attainment of a critical mass of living cells was necessary for the development of traction retinal detachment.

A comparison of different cellular inocula in an experimental model of massive periretinal proliferation.

We modified a preexisting experimental model of massive periretinal proliferation by injecting cells of differing origins into the rabbit vitreous cavity. These cells included autologous and homologous fibroblasts, homologous chondrocytes, homologous retinal pigment epithelial cells, heterologous bovine endothelial cells, and heterologous murine embryonal cells. All cell injections caused vitreous and retinal membrane formation that resulted in a process similar to massive periretinal proliferation. Clinically the character of the membranes formed and the time course in the development of traction retinal detachments was similar for all the different cell types. The initial cell dosage injected was the critical factor in determining the severity of the traction retinal detachments leading to massive periretinal proliferation.

Results of anterior segment surgery with vitrectomy instruments.

We used closed-eye endosurgery to treat 58 patients with anterior segment problems. These included nonsenile cataract, residual lens material, pupillary membranes, vitreocorneal touch, aphakic pupillary block glaucoma, intraocular lens complications, epithelial ingrowth, and total hyphema. Thirty-five eyes showed an increase in visual acuity of more than two Snellen lines, 13 eyes demonstrated no change, and ten eyes lost more than two lines. Complications included endophthalmitis, retinal detachment, retinal tears, increased intraocular pressure, postoperative hemorrhage, and bullous keratopathy.

Ocular complications.

Ocular complications of diabetes in humans are reviewed briefly, and experimental models available for study of the complications are described. Potentially suitable models include not only diabetic animals, but also nondiabetic animals in which analogous lesions have been demonstrated. Many abnormalities of the lens, cornea, iris, and retina comparable to those of diabetes in humans may be observed in diabetic animals, although all abnormalities are not necessarily observed in every species. Retinal changes, in particular, may occur in diabetic animals of several species, but only in large animals (dogs, primates) have saccular capillary aneurysms been reproduced consistently, together with other retinal changes typical of diabetes in humans. A few examples of the uses of animal models are offered, and attention is called to a lack of animal models of proliferative diabetic retinopathy and of rubeosis iridis.

Simulating decreased visual acuity with a contact lens system.

We use a soft contact lens with a central depression into which a hard contact lens can be fitted to simulate conditions that cause decreased visual acuity. This "piggy-back" system can simulate central scotoma, various peripheral field defects, and opacities of the media.

Total hyphema evacuation by vitrectomy instrumentation.

We describe our technique for the surgical removal of hyphema using the Ocutome vitrectomy system and report the results in 12 patients. Blood was removed successfully with just one operation in all 12 eyes. Eleven of the 12 eyes maintained intraocular tension of less than 20 mm Hg. Vision improved in 11 of 12 eyes and six had a vision of 6/18 or better. Permanent vision loss could not be attributed to the operative technique.

Pars plana vitrectomy infusion line in retinal detachment surgery.

We used new applications for a pars plana infusion cannula in three patients with retinal and choroidal detachments. Because the cannula maintained intraocular volume and form, it was helpful in treatment bullous retinal detachment and choroidal detachment.