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Retinal Loci (retinal + locus)

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Medical Sciences	100%

Selected Abstracts

Macular pigment optical density at four retinal loci during 120 days of lutein supplementation

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2007
Adam J. Wenzel
Abstract Background:, Increased consumption of lutein and zeaxanthin has been shown to increase macular pigment optical density (MPOD) in some individuals. Most interventions either obtained infrequent measures of MPOD or measured MPOD at a single retinal locus. Purpose:, The aim of this study was to measure acute changes in MPOD at four retinal loci during lutein intervention. Methods:, For 120 days, three subjects consumed 30 mg of lutein and 2.7 mg of zeaxanthin supplement per day. MPOD was measured with heterochromatic flicker photometry at 20,, 30,, 60, and 120, eccentricity three or four times per week. High-performance liquid chromatography was used to measure serum carotenoid concentrations in blood samples collected at baseline and at 30-day intervals. Results:, At the two most central loci, MPOD significantly increased in all three subjects with a mean change of approximately 0.09 log units at 20, eccentricity and 0.08 log units at 30, eccentricity. MPOD significantly increased in two subjects at 60, eccentricity, and in one subject at 120, eccentricity. The increases in MPOD appeared to be linear and continued after treatment was ended. In all three subjects, log sensitivity at the reference locus decreased linearly. Serum lutein and serum zeaxanthin increased from baseline, reaching peak concentrations after 30 days of supplementation. Conclusion:, The changes in MPOD suggest that carotenoid deposition occurs linearly and may be biased towards the central retina. Further, carotenoid deposition may occur outside the central fovea in interventions with pharmacological doses of carotenoid, resulting in underestimations of psychophysical measures of MPOD. [source]

Retinal sensitivity and fixation changes 1 year after triamcinolone acetonide assisted internal limiting membrane peeling for macular hole surgery , a MP-1 microperimetric study

ACTA OPHTHALMOLOGICA, Issue 6 2010
Hakan Ozdemir
Acta Ophthalmol. 2010: 88: e222,e227 Abstract. Purpose:, To evaluate microperimetric changes 1 year after macular hole surgery with triamcinolone acetonide assisted internal limiting membrane (ILM) peeling. Methods:, Twenty-two eyes of 22 patients with stage 3 and 4 idiopathic macular holes of <6 months' duration underwent vitrectomy with triamcinolone acetonide assisted ILM peeling. Best corrected visual acuity (BCVA) (logarithm of the minimum angle of resolution), and central retinal sensitivity were documented before and 1, 3, 6, and 12 months after surgery. Macular sensitivity (mean sensitivity in decibels -dB), and stability and location of fixation (preferred retinal locus) were determined using MP-1 microperimetry (Nidek). The MP-1 microperimetry sensitivity map was overlaid onto infrared images recorded on a Heidelberg scanning laser ophthalmoscope using dedicated MP-1 software to evaluate the fixation location before surgery. Anatomical success was evaluated with optical coherence tomography (OCT). Optical coherence tomography scans were recorded on an OCT 3000 scanner. Results:, Anatomical success was achieved in all 22 eyes. All patients completed 1 year follow-up. No recurrence of macular hole was seen in any patients in the follow-up period. The mean BCVA improved from 0.75 ± 0.2 before surgery to 0.31 ± 0.1 logMAR at the last visit (p < 0.001). Mean sensitivity improved from 3.7 ± 0.6 to 5.3 ± 1.0 dB at the last visit (p < 0.001). Before surgery, the preferred retinal locus was located on the margin of the hole in all, in 18 eyes on its upper part and in four eyes to the side or on its lower part. Preoperatively, 12 eyes were stable and 10 were relatively unstable, but 12 month after surgery, fixation stability had improved, and 20 eyes were stable and two were relatively unstable. Conclusions:, MP-1 microperimetry sensitivity map overlaid onto an infrared image using dedicated MP-1 software can be used successfully to evaluate fixation location in patients with a macular hole before surgery. With microperimetry findings, we can also measure functional macular changes more precisely than using BCVA alone after macular hole surgery. Our results also showed that retinal sensitivity and fixation properties were improved after vitrectomy with triamcinolone acetonide assisted ILM peeling in patients with idiopathic macular hole. [source]