The Robustness of Various Forms of Perimetry to Different Levels of Induced Intraocular Stray Light

Abstract

The increased stray light values induced by cataract-simulating filters has a significant effect on all tests. However, GRP, which is known to be limited by retinal sampling rather than contrast, remains the most robust of the tests to the effects of intraocular stray light. The degree to which the normative "sensitivity" range for different types of perimetry might incorporate a component caused by individual differences in intraocular stray light is discussed and requires further research.

Flicker Defined Form Perimetry in Glaucoma Suspects with Normal Achromatic Visual Fields

“…The influence of lens opacifications is well known for other perimetrical techniques in early glaucoma like FDT or SWAP. 26 However, only minimal opacifications of the lens were observed on slit-lamp examination clinically when enrolling the glaucoma suspects and the control group participants. The maximum time interval between the two FDF tests was 3 months, so it appears unlikely Copyright of Current Eye Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission.…”

Comparative Resilience of Clinical Perimetric Tests to Induced Levels of Intraocular Straylight

“…[11][12][13][14] Perimetric instruments which are less dependent on contrast sensitivity (modulated along a different scale) may prove to be more resilient to optical media deficits. 15,16 To determine comparative resilience to optical deficits between instruments, the magnitude of the effect of contrast sensitivity on threshold measures should be characterized. White diffusing filters have been used previously to simulate the effects of aging and cataract on perimetry.…”

“…10,[17][18][19][20] The reported results have shown a general depression of the hill of vision with standard automated perimetry (SAP) and frequency doubling technology (FDT) perimetry, which were comparable with the effects of pre-and postoperative cataract extraction. [21][22][23] Anderson et al 15 previously outlined a protocol which aimed at examining the effects of IOS induced by white opacity filters (WOFs; Lee Filters, Andover, UK) on SAP, FDT1, shortwavelength automated perimetry (SWAP) and peripheral grating resolution perimetry (GRP). The WOFs used there contain particles causing scatter analogous to that caused by cataract.…”

“…The WOFs used there contain particles causing scatter analogous to that caused by cataract. 10,15,24 In the report by Bergin et al 16 this protocol was repeated to investigate the effect WOF's on the Humphrey Field Analyzer II (Carl Zeiss Meditec, Dublin, CA), the FDT Matrix (Zeiss, Dublin, CA), the Heidelberg Edge Perimeter (HEP; Heidelberg Engineering, Heidelberg, Germany), and the Moorfields motion displacement test (MDT; Moorfields Eye Hospital, London, UK). In both studies the magnitude of the induced IOS was quantified by a cataract quantifier (Oculus C-Quant; Oculus, Wetzlar, Germany) as described by Franssen and colleagues.…”

“…25 The aim of this study was to investigate the effect of IOS induced by WOFs on threshold measurements for stimuli employed in three perimeters: Octopus SAP (Haag Streit, Koeniz, Switzerland), Pulsar (Haag Streit), and the Moorfields MDT (Moorfields Eye Hospital). Importantly, the protocol outlined by Anderson et al 15 was followed again in this study, to enable the results from the three different studies with eight different instruments to be compared.…”