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D.R. McDowell, K.M. M. Dempsey, R.E. Rainey, R.S. Anderson; The Effects of Simulated Lens Opacity and Age–Related Lens Yellowing on Various Types of Static Perimetry . Invest. Ophthalmol. Vis. Sci. 2005;46(13):710.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose:We sought to investigate the robustness of three commercially available perimetry tests and one more novel form of resolution perimetry to simulated lens opacity and age related lens yellowing. Methods: Three subjects (36 years, 45 years and 60 years) were tested using the Humphrey white–on–white Standard Automated Perimetry (SAP), Short Wavelength Automated Perimetry (SWAP), Frequency Doubling Perimetry (FDP) and Grating Resolution Perimetry (GRP). We used five broadband yellow filters (YF) of increasing density to simulate the spectral absorption changes associated with age–related lens yellowing up to approximately 80 years old, and five white opacity filters (OF) of increasing density to separately simulate the increased light scatter. The yellow filters had transmittance at 488nm ranging from 0.54–0.9. The opacity filters ranged from 0.42–0.86 transmittance, each of which reduced peak contrast sensitivity by approximately 0.1 log units over the previous filter. Results:For the yellow filters, the results indicate that the thresholds for all perimetry tests were not significantly affected, except for SWAP which showed a decline in threshold of 0.95 log units over the range of the five filters. For the opacity filters, all tests were significantly affected (P<0.05), FDP demonstrating a decline of 1.5 log units, SWAP 0.94 log units, SAP 0.9 log units and GRP 0.3 log units over the range of five filter values. The result for GRP is in agreement with previous laboratory studies which have shown that grating resolution in the periphery is relatively unaffected by significant changes in contrast or optical defocus. Conclusions: Simulated age–related lens yellowing appears to have little effect on the perimetry tests employed here, except SWAP which has previously been shown to be vulnerable to lens yellowing. Lens opacification has a more serious effect on all tests except GRP which is known to be limited by retinal sampling rather than contrast and thus remains robust to the effects of lenticular scatter.
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