The assessment of choroidal thickness with spectral-domain optical coherence tomography during Valsalva maneuver.

PURPOSE: The purpose of the study was to evaluate the effect of Valsalva maneuver (VM) on choroidal thickness. METHODS: All the volunteers underwent a detailed opthalmic examination. Third-generation Spectralis OCT device (software version 5.6.3.0; Spectralis OCT, Heidelberg Engineering, Dossenheim, Germany) was used for assessment. Subfoveal and perifoveal CT of all volunteers were measured by using EDI-OCT technology. Perifoveal CT was measured 1500 µm nasally and 1500 µm temporally apart from the foveal center. The measurements were repeated while volunteers were performing VM. RESULTS: Sixty-four eyes of 32 healthy volunteers were assessed. The volunteers were aged 29-50. The mean age was 32.8 ± 6.6 years. Choroidal thickness measurements differed with statistical significance between resting position and VMin all regions (p < 0.001). While mean subfoveal CT was 350.64 ± 87.73 µm during resting position, it was 369.95 ± 90.12 µm during VM (p < 0.001). While mean nasal CT was 292.14 ± 81.67 µm during resting position, it was 305.46 ± 85.80 µm during VM (p < 0.001). While mean temporal CT was 325.93 ± 80.91 µm during resting position, it was 343.21 ± 81.53 µm during VM (p < 0.001). CONCLUSIONS: We found statistically significant increase in choroidal thickness during the VM in healthy volunteers. This result might be important for future studies researching autoregulation of choroidal and retinal blood flow in physiologic and pathologic conditions. Also, our study is noteworthy to stand out the errors in EDI-OCT measurements caused by unintentional breath holding of patients.

Reliability of intravitreal nepafenac in rabbits.

PURPOSE: The purpose of this experiment was to investigate the possible toxic effects of Nepafenac, a nonsteroidal anti-inflammatory molecule, after its intravitreal application in various concentrations. METHODS: Forty pigmented rabbits were randomly divided into 4 groups, each including 10 rabbits. The active ingredient Nepafenac was prepared to be applied in different doses, for intravitreal use. Under topical anesthesia, following pupil dilatation, 0.3, 0.5, 0.75, and 1.5 mg doses of Nepafenac was applied intravitreally into the right eye. In each rabbit, the right eye was considered to be the study group. Saline was injected intravitreally into the left eye of each rabbit, and these eyes were considered to be the control group. Immediately after the injection and at the 1st, 4th, and 8th weeks, fundus examination by indirect ophthalmoscopy and intraocular pressure measurement were conducted. Furthermore, electroretinographic (ERG) recordings were taken at the 4th and 8th weeks. At the end of the 8th week, eyes of the surviving 26 rabbits were enucleated, and then animals were sacrificed. Following necessary fixation procedures, histopathological investigations were conducted by using a light and electron microscope. In the histological cross sections, differences between the eyes with injection and the control group were evaluated, and total retinal thickness, inner nuclear layer thickness, and outer nuclear layer thickness were measured. RESULTS: No pathology was found by clinical examination of either group. In the photopic and scotopic full-field ERG, conducted before the injection and in the 4th and 8th weeks after the injection, no statistically significant difference was determined between the study group and the control group. In the histological evaluation of the preparations, there were no statistically significant differences in the retina thickness of control and study groups. In the electron microscopic examinations, there were no toxicity findings in the eyes with injection. CONCLUSIONS: Our data show that intravitreal application of 0.3, 0.5, 0.75, and 1.5 mg doses of Nepafenac active substance is nontoxic to the rabbit retina.

Systemic endothelial function in primary open-angle glaucoma.

Objective. We aimed to assess peripheral vascular endothelial function in open-angle glaucoma (POAG) by measuring flow-mediated dilatation (FMD). Materials and Methods. The study included 20 cases with POAG (group 1, mean age 58.68 ± 13.3 years) and 30 healthy individuals (group 2, mean age 58.68 ± 13.6 years). In all cases, responses of endothelial function were assessed by a cardiologist through measurement of FMD following brachial artery occlusion. Results. Mean percent of FMD, an indicator of endothelial function, was found to be 11.9 ± 4.2% in group 1 and 12.3 ± 4.4% in group 2 (P = 0.86). Conclusion. No impairment in systemic vascular function of cases with POAG suggests that POAG could be a local disorder rather than being a component of systemic disease.