Successful treatment with repeated dexamethasone implant injections for recurrent macular edema after acute retinal necrosis.

BACKGROUND: The treatment of recurrent cystoid macular edema associated with acute retinal necrosis is challenging due to the concern that treatment with intravitreal steroids may reactivate the retinitis. CASE REPORT: An immunocompetent patient diagnosed with acute retinal necrosis was treated with oral valacyclovir and intravitreal injections of foscarnet. Giant tears in her retina necessitated a vitrectomy with silicone oil. She developed cystoid macular edema after the removal of the silicone oil. The edema responded to high-dose prednisolone but recurred when the dose was tapered to 20 mg daily. Under close surveillance and increased antiviral medication, she was treated with a dexamethasone implant with complete resolution of the edema. Unfortunately, the edema recurred, and the treatment had to be repeated. Over 18 months, she received five dexamethasone implants without recurrence of the viral retinitis. CONCLUSIONS: This case shows successful treatment of recurring cystoid macular edema following acute retinal necrosis with repeated intravitreal dexamethasone implants in a patient receiving valacyclovir maintenance treatment.

National application of the European visual field standards for driving: a survey study.

Aims: To provide an overview of how the European visual field standards for driving (specified in Commission Directive 2009/113/EC) are applied and determine whether individuals with visual field defects are treated equally across Europe. Methods: One ophthalmic expert from each of 32 European countries was invited to participate in an electronic survey. They were presented with threshold and Esterman perimetry results of 15 cases of visual field defects and asked to classify each case as either passed or failed in reference to their national standards. The results were compared with the European Driving Test Group 1 (EDT1), which is a new perimetry algorithm that adheres to the recommendations by the Eyesight Working Group. Fleiss' kappa was used to determine the inter-rater agreement. Results: Twenty-five countries responded. Three of 15 cases were passed by all. Full agreement on a failed case was not reached. Denmark graded most leniently and passed 12 cases. Bulgaria, Romania and Slovakia graded most strictly and passed five cases. The Fleiss' kappa score was 0.52 (95% CI 0.49 to 0.55). Only Slovenia was in full agreement with the EDT1. Fifteen countries endorsed specific perimetric tests for assessing fitness to drive. Five of these also defined pass/fail criteria. Conclusion: The directive fails to establish a uniform approach to the visual field requirements, as evident by moderate pass/fail agreement between the national experts. Because the visual standards for driving are enforced differently, identical visual field loss can result in either revocation or approval of a driving license.

A traffic perimetry test that adheres to the European visual field requirements.

PURPOSE: European visual requirements for driving generally follow the standards of the European Union (EU), but the lack of a uniform perimetry algorithm leads to differing practices in enforcing visual field regulations. The purpose of this study was to develop a perimetry algorithm for group 1 driving licenses (car and motorcycle) that adheres to the European requirements. METHODS: We determined the features of a traffic perimetry algorithm complying with the EU directive 2009/113/EC and the underlying scientific report by the Eyesight Working Group. The final algorithm was a binocular, supra-threshold test with 37 central and 86 peripheral test points within 140º x 40º. It was created as a custom test for an Octopus 900 perimeter and tested on participants with known visual field defects. Findings were compared with the Esterman program in reference to British and Norwegian regulations, which both recommend the Esterman program for assessing fitness to drive but differ in definition of negative and positive results. RESULTS: Twenty-five participants were examined. In comparison with the traffic perimetry algorithm, sensitivity and specificity of the British regulations were 0.78 (95% confidence interval (CI) 0.40-0.97) and 1.00 (95% CI 0.79-1.00). Similarly, sensitivity and specificity of the Norwegian regulations were 0.89 (95% CI 0.52-1.00) and 0.81 (95% CI 0.54-0.96). CONCLUSION: The lack of a perimetry algorithm that conforms to the scientific recommendations challenges the fundamental right of European drivers for legal equality. This study demonstrates a binocular supra-threshold test that adheres to the European visual field requirements for group 1 driving licenses.

Oxygen saturation in human retinal vessels is higher in dark than in light.

PURPOSE: Animal studies have indicated that retinal oxygen consumption is greater in dark than light. In this study, oxygen saturation is measured in retinal vessels of healthy humans during dark and light. METHODS: The oximeter consists of a fundus camera, a beam splitter, a digital camera and software, which calculates hemoglobin oxygen saturation in the retinal vessels. In the first experiment, 18 healthy individuals underwent oximetry measurements after 30 minutes in the dark, followed by alternating 5-minute periods of white light (80 cd/m(2)) and dark. In the second experiment, 23 volunteers underwent oximetry measurements after 30 minutes in the dark, followed by light at 1, 10, and 100 cd/m(2). Three subjects were excluded from analysis in the first experiment and four in the second experiment because of poor image quality. RESULTS: In the first experiment, the arteriolar saturation decreased from 92% +/- 4% (n = 15; mean +/- SD) after 30 minutes in the dark to 89% +/- 5% after 5 minutes in the light (P = 0.008). Corresponding numbers for venules are 60% +/- 5% in the dark and 55% +/- 10% (P = 0.020) in the light. In the second experiment, the arteriolar saturation was 92% +/- 4% in the dark and 88% +/- 7% in 100 cd/m(2) light (n = 19, P = 0.012). The corresponding values for venules were 59% +/- 9% in the dark and 55% +/- 10% in 100 cd/m(2) light (P = 0.065). CONCLUSIONS: Oxygen saturation in retinal blood vessels is higher in dark than in 80 or 100 cd/m(2) light in human retinal arterioles and venules. The authors propose that this is a consequence of increased oxygen demand in the outer retina in the dark.