Randomized trial of peribulbar triamcinolone acetonide with and without focal photocoagulation for mild diabetic macular edema: a pilot study.

OBJECTIVE: To provide pilot data on the safety and efficacy of anterior and posterior sub-Tenon injections of triamcinolone either alone or in combination with focal photocoagulation in the treatment of mild diabetic macular edema (DME). DESIGN: Prospective, phase II, multicenter, randomized clinical trial. PARTICIPANTS: One hundred nine patients (129 eyes) with mild DME and visual acuity 20/40 or better. METHODS: The participants were assigned randomly to receive either focal photocoagulation (n = 38), a 20-mg anterior sub-Tenon injection of triamcinolone (n = 23), a 20-mg anterior sub-Tenon injection followed by focal photocoagulation after 4 weeks (n = 25), a 40-mg posterior sub-Tenon injection of triamcinolone (n = 21), or a 40-mg posterior sub-Tenon injection followed by focal photocoagulation after 4 weeks (n = 22). Follow-up visits were performed at 4, 8, 17, and 34 weeks. MAIN OUTCOME MEASURES: Change in visual acuity and retinal thickness measured with optical coherence tomography (OCT). RESULTS: At baseline, mean visual acuity in the study eyes was 20/25 and mean OCT central subfield thickness was 328 mum. Changes in retinal thickening and in visual acuity were not significantly different among the 5 groups at 34 weeks (P = 0.46 and P = 0.94, respectively). There was a suggestion of a greater proportion of eyes having a central subfield thickness less than 250 mum at 17 weeks when the peribulbar triamcinolone was combined with focal photocoagulation. Elevated intraocular pressure and ptosis were adverse effects attributable to the injections. CONCLUSIONS: In cases of DME with good visual acuity, peribulbar triamcinolone, with or without focal photocoagulation, is unlikely to be of substantial benefit. Based on these results, a phase III trial to evaluate the benefit of these treatments for mild DME is not warranted.

The safety of intravitreal hyaluronidase. A clinical and histologic study.

The authors previously developed a new model of preretinal neovascularization in the rabbit eye using hyaluronidase for enzymatic vitreolysis. The purpose of this study was to evaluate the safety of intravitreal injections of hyaluronidase. Concentrations of 1, 15, 30, 50, and 150 IU of hyaluronidase in 0.1 ml of 0.9% saline were injected intravitreally and aspirated repetitively until the vitreous was partially liquified. The animals were examined with indirect ophthalmoscopy, fundus photography, and fluorescein angiography before injection and on days 1 and 7 after injection. Light and electron microscopic retinal sections were prepared from enucleated eyes at days 1 and 7. All concentrations of hyaluronidase were effective in producing partial vitreolysis. Eyes treated with 1 IU showed no abnormalities on days 1 or 7. Eyes treated with 15 IU showed no retinal abnormalities on day 1, but on day 7 histologic abnormalities were present in two of four eyes. At higher concentrations, clinical and histologic changes were seen in proportion to the concentration and included focal whitening, edema, vitreous haze, vascular abnormalities, and retinal necrosis at the highest doses. Histologic evaluation of the retina revealed marked destruction in all layers at the higher concentrations. The authors conclude that 1 IU of intravitreal hyaluronidase is sufficient for partial vitreolysis and nontoxic to the rabbit retina.

An experimental model of preretinal neovascularization in the rabbit.

Although progressive retinal neovascularization is a potentially blinding complication of several diseases, there are no good animal models. The authors developed a consistent model of preretinal neovascularization in the rabbit by partially digesting the posterior vitreous with repeated injection and aspiration of 1 IU of hyaluronidase before injection of 250,000 homologous dermal fibroblasts. The evolution of the new preretinal vessels was monitored by indirect ophthalmoscopy, fundus photography, and fluorescein angiography. A grading system was devised using fundus photographs and fluorescein angiograms to describe the progression of new vessel growth and the extent of fluorescein leakage. Ninety-five percent of the eyes had vascular enlargement and hyperemia but no fluorescein leakage by day 1. Fifteen percent of the eyes had clinically evident new preretinal vessels, and 32% had severe fluorescein leakage by day 7. Ninety-five percent of the eyes had definite neovascularization by day 14. Severe fluorescein leakage peaked at day 14 (55% of the eyes) and decreased thereafter. Involution or atrophy of the vessels occurred in all eyes by day 42. This model will be useful for studying the pathogenesis of preretinal neovascularization and evaluating potential treatments for its prevention.

Silicone oil injection after failed primary vitreous surgery in severe ocular trauma.

In 42 cases of complicated retinal detachment following trauma after failed primary vitrectomy, at six months follow-up anatomic retinal reattachment posterior to the scleral buckle was achieved in 20 of 40 eyes (50%). Of the 40 eyes, 11 (28%) had a visual acuity of 5/200 or better. Of the eyes that were completely attached posterior to the buckle at six months, 13 of the 20 (65%) remained attached at the last follow-up examination. Many patients who had visual acuities of 5/200 or better at six months experienced a progressive decrease in visual acuity over three years, primarily because of recurrent retinal detachments and corneal edema. A final visual acuity of 5/200 or better was obtained in only five of the 42 eyes (12%) at the last follow-up examination.

Contralateral decreased visual acuity and extraocular muscle palsies following retrobulbar anesthesia.

Numerous complications resulting from retrobulbar injections in the injected eye and orbit have been reported. A rare complication of retrobulbar anesthesia is the occurrence of decreased visual acuity and extraocular muscle palsies in the contralateral eye. We report three cases of contralateral dysfunction of cranial nerves II and III, following retrobulbar anesthesia. None of the patients suffered permanent sequelae. Several methods of decreasing the probability of such an occurrence are discussed.

Laser chorioretinal venous anastomosis for nonischemic central retinal vein occlusion.

OBJECTIVE: This study aimed to test the efficacy and safety of laser chorioretinal anastomosis for central retinal vein occlusion (CRVO). DESIGN: The study design was a consecutive case series. PARTICIPANTS: Eight eyes of eight patients were treated. INTERVENTION: The argon laser was used in the method of McAllister and Constable to attempt to form an anastomosis. The patients were observed for 1 to 19 months (median, 11 months). MAIN OUTCOME MEASURES: Visual acuity, anastomosis success, and complications were measured. RESULTS: Twenty attempts to create anastomoses were made with 2 successful anastomoses but not of a therapeutic type. Three patients developed rubeosis, retinal neovascularization at the laser site, and vitreous hemorrhage. Traction retinal detachment occurred twice and neovascular glaucoma occurred once. Secondary panretinal photocoagulation, pars plana vitrectomy, and glaucoma seton were required in three patients, one patient, and one patient, respectively. Visual acuity improved in two patients independent of failed attempts at anastomosis creation and did not improve or worsened in six patients, including the two patients with the successfully created anastomoses. CONCLUSION: Laser chorioretinal anastomosis for nonischemic CRVO has greater risks and less success than the initial report suggested. Further refinement of the technique is needed before it is adopted extensively. Even when successful, macular pigment epithelial scarring can limit vision, implying a relatively short time window for its effective application in the face of severe macular edema. Successful laser chorioretinal anastomosis does not preclude development of anterior segment neovascularization.

The effect of the surgeon and the laser wavelength on the response to focal photocoagulation for diabetic macular edema.

OBJECTIVE: To determine the effect of the surgeon and the wavelength of laser used on the response to focal photocoagulation for diabetic macular edema. DESIGN: Retrospective case-control study. PARTICIPANTS: Forty-four matched pairs of cases by two different retina surgeons in the study of surgeon influence were examined. Sixty-nine matched pairs of cases using dye yellow versus argon green laser treatment in the study of wavelength influence also were studied. In both studies, eyes were matched for the only patient-dependent variables affecting outcome: age, initial visual acuity, follow-up time, and diabetic control by diet versus any other method. INTERVENTION: Focal laser photocoagulation for clinically significant diabetic macular edema was performed. MAIN OUTCOME MEASURE: Visual acuity at 6 months follow-up was measured. RESULTS: For the study in which the only difference was the surgeon, at 6 months follow-up the mean difference in logarithm of the minimum angle of resolution (logMAR) visual acuity was -0.045, 95% confidence interval (-0.160, 0.070). For the study in which wavelength varied, at 6 months the mean difference in logMAR visual acuity was -0.048, 95% confidence interval (-0.147, 0.052). The power of the surgeon study to detect a difference in the logMAR visual acuity of 0.3 is 88% and of the wavelength study to detect this difference is 99%. CONCLUSION: In looking at the 6-month visual outcome after focal laser photocoagulation for clinically significant diabetic macular edema, different fellowship trained surgeons and the choice of green or yellow wavelength had no effect on the treatment outcome.

The effects of intravitreal triamcinolone acetonide on experimental pre-retinal neovascularization.

Corticosteroids, alone or in combination with other drugs, have been shown to inhibit angiogenesis. The purpose of this study was to evaluate the efficacy of triamcinolone acetonide in a new model of preretinal neovascularization. Rabbit eyes were treated with intravitreal triamcinolone acetonide 24 h before partial liquefaction of the posterior vitreous with hyaluronidase and injection of 250,000 homologous tissue-cultured dermal fibroblasts. Triamcinolone acetonide effectively inhibited new vessel growth in treated eyes. Only 14% of the treated eyes developed new blood vessels compared to 100% of sham-injected control eyes (P < 0.001). These results suggest that intravitreal triamcinolone acetonide might be effective in inhibiting new vessel growth in patients with inflammatory retinal neovascularization, such as that associated with sarcoidosis or other uveitic syndromes.

Photic maculopathy after extracapsular cataract surgery. A prospective study.

Photic retinal injuries have been described after surgical exposure to the intense illumination systems of operating microscopes. The overall incidence of such injuries has been postulated at less than 10%. The authors prospectively studied 43 consecutive patients to determine the incidence of photic macular injuries during cataract surgery. Patients underwent complete ophthalmic examinations, fundus photography, and oral fluorography before and after surgery. Photic macular injuries developed in 12 of 43 eyes (28%) as a result of intraocular surgery. This incidence is much higher than previous estimates. The association with possible risk factors, cystoid macular edema, and the effect of these injuries on final visual acuity are discussed.