Gene therapy for leber congenital amaurosis caused by RPE65 mutations: safety and efficacy in 15 children and adults followed up to 3 years.

OBJECTIVE: To determine the safety and efficacy of subretinal gene therapy in the RPE65 form of Leber congenital amaurosis using recombinant adeno-associated virus 2 (rAAV2) carrying the RPE65 gene. DESIGN: Open-label, dose-escalation phase I study of 15 patients (range, 11-30 years of age) evaluated after subretinal injection of the rAAV2- RPE65 vector into the worse-functioning eye. Five cohorts represented 4 dose levels and 2 different injection strategies. MAIN OUTCOME MEASURES: Primary outcomes were systemic and ocular safety. Secondary outcomes assayed visual function with dark-adapted full-field sensitivity testing and visual acuity with Early Treatment Diabetic Retinopathy Study charts. Further assays included immune responses to the vector, static visual fields, pupillometry, mobility performance, and optical coherence tomography. RESULTS: No systemic toxicity was detected; ocular adverse events were related to surgery. Visual function improved in all patients to different degrees; improvements were localized to treated areas. Cone and rod sensitivities increased significantly in the study eyes but not in the control eyes. Minor acuity improvements were recorded in many study and control eyes. Major acuity improvements occurred in study eyes with the lowest entry acuities and parafoveal fixation loci treated with subretinal injections. Other patients with better foveal structure lost retinal thickness and acuity after subfoveal injections. CONCLUSIONS: Gene therapy for Leber congenital amaurosis caused by RPE65 mutations is sufficiently safe and substantially efficacious in the extrafoveal retina. There is no benefit and some risk in treating the fovea. No evidence of age-dependent effects was found. Our results point to specific treatment strategies for subsequent phases. APPLICATION TO CLINICAL PRACTICE: Gene therapy for inherited retinal disease has the potential to become a future part of clinical practice. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00481546.

Ab-externo AAV-mediated gene delivery to the suprachoroidal space using a 250 micron flexible microcatheter.

BACKGROUND: The current method of delivering gene replacement to the posterior segment of the eye involves a three-port pars plana vitrectomy followed by injection of the agent through a 37-gauge cannula, which is potentially wrought with retinal complications. In this paper we investigate the safety and efficacy of delivering adeno-associated viral (AAV) vector to the suprachoroidal space using an ab externo approach that utilizes an illuminated microcatheter. METHODS: 6 New Zealand White rabbits and 2 Dutch Belted rabbits were used to evaluate the ab externo delivery method. sc-AAV5-smCBA-hGFP vector was delivered into the suprachoroidal space using an illuminated iTrackTM 250A microcatheter. Six weeks after surgery, the rabbits were sacrificed and their eyes evaluated for AAV transfection using immunofluorescent antibody staining of GFP. RESULTS: Immunostaining of sectioned and whole-mounted eyes demonstrated robust transfection in all treated eyes, with no fluorescence in untreated control eyes. Transfection occurred diffusely and involved both the choroid and the retina. No apparent adverse effects caused by either the viral vector or the procedure itself could be seen either clinically or histologically. CONCLUSIONS: The ab externo method of delivery using a microcatheter was successful in safely and effectively delivering a gene therapy agent to the suprachoroidal space. This method presents a less invasive alternative to the current method of virally vectored gene delivery.

Multifocal juvenile xanthogranuloma presenting with a hand mass and bilateral vitreous hemorrhage in a neonate.

PURPOSE: To describe a rare case of multifocal juvenile xanthogranuloma (JXG) in a neonate presenting with a large hand mass, bilateral vitreous hemorrhage, and posterior segment involvement. METHODS: Biopsy of hand lesion led to the diagnosis of JXG. Further systemic workup and ocular examination revealed bilateral vitreous hemorrhage and a small, creamy yellowish subretinal lesion above the fovea in the macula of the left eye. In addition, there was a subretinal lesion with overlying vitreous fibrosis in the inferonasal quadrant of the left eye. RESULTS: Treatment with prednisone (2 mg/kg/day) for 2 weeks was initiated before final diagnosis of hand lesion. Steroids were then tapered off over the course of a week with no additional treatment. Follow-up examinations were performed over the course of the next 17 months. On the last follow-up examination at the age of 20 months, the child had central steady and maintained fixation in each eye. The findings of an external ocular examination were unremarkable except for a mild myopic shift in the right eye secondary to trace cataract changes. Dilated fundus examination showed resolution of the lesions in the macula and inferonasal quadrant of the left eye. CONCLUSION: Although rare, JXG should be included in the differential diagnosis of spontaneous vitreous hemorrhage in children under the age of 2 years. Topical, periocular, and oral steroids may improve the ocular signs and symptoms in this condition and should be considered in the management of ophthalmic manifestations of JXG.

Visual loss due to central serous chorioretinopathy during corticosteroid treatment for giant cell arteritis.

Giant cell arteritis (GCA) can be a devastating disease resulting in blindness if not promptly diagnosed and treated. The only proven treatment for GCA is systemic corticosteroids; however, there are many side-effects associated with this therapy including ocular side-effects such as ocular hypertension, cataract formation and central serous chorioretinopathy. To raise physician awareness, a patient with biopsy-proven GCA is reported who lost vision during corticosteroid therapy because of central serous chorioretinopathy.

Ocular photodynamic therapy in choroidal neovascularization complicating idiopathic central serous chorioretinopathy.

Two consecutive patients with idiopathic central serous chorioretinopathy and decreased vision subsequent to subfoveal choroidal neovascular membranes were treated with photodynamic therapy applied using the protocol of the Treatment of Age-Related Macular Degeneration with Photodynamic Therapy Study Group. Main outcome measures included best-corrected visual acuity, biomicroscopic appearance, and leakage on fluorescein and indocyanine green angiography. Photodynamic therapy offered anatomical, angiographic, and functional improvement. After an initial complete response, the patients required re-treatment at 3 and 4 months, respectively. Cessation of leakage with improvement in visual acuity occurred, but subretinal fibrosis posed a possible limitation for full functional recovery. Although choroidal neovascular membranes complicating idiopathic central serous chorioretinopathy portend a poor visual prognosis, the overall response to photodynamic therapy was favorable.

Bilateral ulnar decubitus as a complication of macular hole surgery.

Bilateral ulnar decubitus is described in a 69-year-old patient maintaining prone positioning after vitrectomy, membrane peeling, and perfluoropropane gas injection for the treatment of a macular hole. Patients should be warned to report any skin breakdown or ulnar paresthesias resulting from positioning and to change position frequently to allow weight bearing on other parts of the body. Patients with certain personality traits may be more likely to maintain correct positioning despite pain or injury to ensure surgical success.

The effect of intraoperative retinal manipulation on the underlying retinal pigment epithelium: an experimental study.

PURPOSE: Retinal pigment epithelial changes described after vitreoretinal surgery may result from localized compression injury caused by intentional or inadvertent contact with vitreoretinal instruments. The authors evaluated these changes resulting from manipulation of the retina without frank retinal injury. METHODS: One eye each of six pigmented rabbits underwent surgery during which the inner retinal surface was touched at several points with a 20-gauge silicone-tipped subretinal fluid cannula without causing a retinal break or subretinal hemorrhage. The rabbits were followed-up with indirect ophthalmoscopy, fundus photography, and fluorescein angiography, and were killed at 1 hour, 1 week, or 2 weeks. Light microscopy was used for histopathologic evaluation. RESULTS: On fluorescein angiography, diffuse leakage noted at the injury sites significantly decreased by the fourth day and almost completely disappeared by the second week. Disruption of photoreceptor outer segments and retinal pigment epithelium in the early specimens, and irregular pigmentation, proliferation, and migration of the retinal pigment epithelium at 1 and 2 weeks were the prominent features on histopathologic examination. CONCLUSIONS: Intraoperative manipulation of the attached retina may cause significant pigment epithelium displacement and proliferation and varying degrees of disorganization of normal retinal architecture in the absence of clinically evident retinal breaks and subretinal hemorrhages.

Diagnostic use of a rigid contact lens to show corneal topography abnormalities after laser refractive surgery.

We describe 2 cases in which evaluation of rigid contact lens fluorescein patterns were used to delineate and characterize topography irregularities. Contact lens analysis confirmed and localized topography findings of an elevated central island in 1 patient and a semicircular pattern in the other patient. To determine a therapeutic strategy to correct topography irregularities after laser refractive surgery, it is critical to document a corneal elevation and delineate its location.