Canthaxanthin retinopathy with visual loss: a case report and review.

Canthaxanthin is a naturally occurring chemical, which is most commonly utilized as a colorant for food and dyes or a skin bronzing agent. Its most prevalent impact on human health is canthaxanthin retinopathy, which appears as birefringent, yellow to red crystals surrounding the macula. This occurs with increasing, dose-dependent exposure. Generally, patients remain asymptomatic and findings may only be evident on funduscopic examination. Cessation of canthaxanthin ingestion appears to reverse the retinopathy, but the time until crystal disappearance is variable. Despite a usually favorable outcome, long-standing visual changes may occur. We report a case of an 84-year-old woman with significant visual loss secondary to canthaxanthin retinopathy that ultimately improved upon cessation of the drug.

Minimally invasive method for repair of rhegmatogenous retinal detachment following treatment for retinoblastoma.

A minimally invasive method for repair of rhegmatogenous retinal detachment following treatment of retinoblastoma is described. Two children with retinoblastoma developed rhegmatogenous retinal detachments following treatment with a combination of chemotherapy and cryotherapy. Each eye underwent a non-drainage scleral buckling procedure without retinopexy of the retinal break. Postoperatively, the retinas reattached and retinopexy with indirect laser photocoagulation was performed during subsequent examinations under anesthesia. The retinas have remained attached with 2 to 5 years of follow-up. The tumor recurred in case 2, was treated with additional chemotherapy, and has undergone type 1 regression. Non-drainage scleral buckling without retinopexy is a useful technique for repairing rhegmatogenous retinal detachment in eyes with retinoblastoma. The retinal break can be treated postoperatively with indirect laser photocoagulation to minimize the chance of viable tumor cell dissemination.

Intravitreal triamcinolone for treatment of complicated proliferative diabetic retinopathy and proliferative vitreoretinopathy.

BACKGROUND: We present a retrospective evaluation of the clinical outcome and complications associated with intravitreal injection of unaltered triamcinolone acetonide in conjunction with pars plana vitrectomy and silicone oil injection for the treatment of complicated proliferative diabetic retinopathy with tractional retinal detachment and severe proliferative vitreoretinopathy. METHODS: Thirteen eyes of 12 consecutive patients were identified from a computerized patient database. All eyes were operated on by the same surgeon and received 4 mg of unaltered, commercially available triamcinolone acetonide intravitreally, before silicone oil injection. The patients were followed for a mean of 4.7 months (range 1-15 months), and demographic as well as pertinent preoperative and postoperative clinical information was gathered. RESULTS: At the last follow-up visit, vision had improved in 4 eyes, remained stable in 5 eyes, and worsened in 4 eyes. The retina was attached at the end of follow-up in 10 of the 13 eyes. Eight of the 13 eyes did not show any clinical signs of re-roliferation or redetachment during the course of follow-up. The mean intra-ocular pressure did not increase (preoperative value was 10.8+/- 6.22 mm Hg with a range of 0-22 mm Hg; at last follow-up, mean pressure was 9.6 +/-3.86 mm Hg with a cumulative postoperative range of 0-26 mm Hg). Steroid crystals were visible at 1 month postoperatively in 3 eyes and did not hinder fundus examination significantly. INTERPRETATION: The intravitreal injection of low-dose, unaltered triamcinolone acetonide in the setting of pars plana vitrectomy and silicone oil injection for the treatment of proliferative vitreoretinopathy and complicated proliferative diabetic retinopathy appears to be well tolerated. Further controlled study is needed to clearly define the potential beneficial effects of intravitreal steroids in these 2 disease processes.

Vascular perfusion of choroidal melanoma by 3.0 tesla magnetic resonance imaging.

PURPOSE: Because signal-to-noise performance improves with increased magnetic field strength, the quality of magnetic resonance images is greater at 3.0 tesla (T) than at 1.5 T. Because of the longer T1 values at higher field strength, intravenously administered magnetic resonance contrast agents provide improved T1 enhancement at 3.0 T. We have used these factors to obtain high-quality contrast-enhanced imaging of small intraocular lesions using a standard head radiofrequency volume coil. Specifically, we have examined lesion size and magnitude of maximum contrast enhancement in a series of intraocular melanomas before and during therapy. METHODS: Eighteen patients with intraocular masses were examined by 3.0 T magnetic resonance imaging (MRI) including intravenous contrast enhancement. Precontrast images were acquired through the orbits followed by sequential postcontrast images at 1-minute intervals for 5 minutes. The magnitude of contrast enhancement of the lesion, extraocular muscles, and brain parenchyma was measured as a percentage increase in magnetic resonance signal over the preenhancement signal intensity. RESULTS: Lesions demonstrated different levels of enhancement ranging up to 130%. Three patterns of enhancement--0% to 20%, 20% to 50%, and >50%-were identified. Brain parenchyma, benign lesions, and responsive tumors following brachytherapy with 125I demonstrated enhancement of less than 20%. Four choroidal melanomas showed intermediate (20% to 50%) levels of enhancement. Four malignant lesions (three melanomas, one metastatic tumor), as well as the extraocular muscles, showed strong, rapid enhancement (>50%). Four patients who had MRI studies before and following plaque brachytherapy ultimately demonstrated a decline in the contrast enhancement following treatment. CONCLUSIONS: Contrast enhancement of intraocular lesions measured by 3.0 T MRI demonstrates different patterns of enhancement that may be useful for indicating the degree of malignancy and in monitoring response to therapy.

Confocal microscopy in multiple myeloma crystalline keratopathy.

PURPOSE: To report confocal microscopy findings of a patient with multiple myeloma crystalline keratopathy and the response to treatment. METHODS: Confocal microscopy images of the cornea were taken OU and the corneal crystals analyzed using the Cell Counter software. RESULTS: Numerous hyperreflective globules 6-11 nm in size were located within the corneal epithelium and anterior stroma. These crystals obscured normal architectural detail of the cornea. After 6 months of chemotherapy, confocal microscopy was repeated and demonstrated decrease in the size and number of hyperreflective globules. CONCLUSION: Confocal microscopy can enable the clinician to monitor the clinical response of multiple myeloma crystalline keratopathy to chemotherapeutic agents.