Influence of Clinical Factors and Magnification Correction on Normal Thickness Profiles of Macular Retinal Layers Using Optical Coherence Tomography

Abstract

PurposeTo identify the factors which significantly contribute to the thickness variabilities in macular retinal layers measured by optical coherence tomography with or without magnification correction of analytical areas in normal subjects.MethodsThe thickness of retinal layers {retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCLIPL), RNFL plus GCLIPL (ganglion cell complex, GCC), total retina, total retina minus GCC (outer retina)} were measured by macular scans (RS-3000, NIDEK) in 202 eyes of 202 normal Asian subjects aged 20 to 60 years. The analytical areas were defined by three concentric circles (1-, 3- and 6-mm nominal diameters) with or without magnification correction. For each layer thickness, a semipartial correlation (sr) was calculated for explanatory variables including age, gender, axial length, corneal curvature, and signal strength index.ResultsOuter retinal thickness was significantly thinner in females than in males (sr2, 0.07 to 0.13) regardless of analytical areas or magnification correction. Without magnification correction, axial length had a significant positive sr with RNFL (sr2, 0.12 to 0.33) and a negative sr with GCLIPL (sr2, 0.22 to 0.31), GCC (sr2, 0.03 to 0.17), total retina (sr2, 0.07 to 0.17) and outer retina (sr2, 0.16 to 0.29) in multiple analytical areas. The significant sr in RNFL, GCLIPL and GCC became mostly insignificant following magnification correction.ConclusionsThe strong correlation between the thickness of inner retinal layers and axial length appeared to result from magnification effects. Outer retinal thickness may differ by gender and axial length independently of magnification correction.

Comparison of Sectoral Structure-Function Relationships in Glaucoma: Vessel Density Versus Thickness in the Peripapillary Retinal Nerve Fiber Layer

“…When compared with RNFL thickness, the degree of correlation between VD and VF sensitivity was similar in the IT and ST sectors where RNFL thickness showed the strongest correlation with VF sensitivity. 11,30 In contrast, the correlation with VF sensitivity was different in the nasal sector where VD had a relatively weak but significant correlation, whereas RNFL thickness showed no significant correlation. Thus, RNFL VD showed more uniform correlation with VF sensitivity around the optic disc than RNFL thickness, which may be advanta- The sr was determined in multiple linear regression models controlling for the effects of sex, age, axial length, disc area, gamma-and beta-PPA zones, the beta-plus gamma-PPA zone extending into the VD measurement area in the same sector as VD, and SSI.…”

“…To examine the influence of RNFL VD and RNFL thickness on the VF sensitivity by sector, a semipartial correlation coefficient (sr) was determined using multiple linear regression models adjusting for potential confounders. 30 A significant sr indicates that a significant amount of variance in the objective variable is attributed to an explanatory variable independent of the other covariates. The sr 2 (sr squared) value indicates the proportion of total variance in the objective variable uniquely accounted for by an explanatory variable controlling for other covariates.…”

Systemic and Ocular Determinants of Peripapillary Retinal Nerve Fiber Layer Thickness Measurements in the European Eye Epidemiology (E3) Population

“…The underlying mechanisms of the association of longer AL and thinner pRNFLT are arguable 20 . Frequently suggested mechanisms are either a stretching due to a longer eye bulb or artificially decreased measurements due to magnification 21,22 . However, irrespective of the causal mechanism, the clinical relevance of adjusting for refraction or AL in OCTimaging seems obvious.…”

Effect of corneal refractive surgery on optical coherence tomography measurements

“…Однако у пациентов с миопией высокой степени использование ОКТ в диагностике глаукомы сопряжено с серьезными трудностями, что связано как с патологическими изменениями при осложненной близорукости, так и с влиянием оптической системы миопического глаза на параметры ОКТ [3,4,6,23,24]. Сравнительно неплохо выяснен только вопрос о влиянии длины оси глаза на показатели, измеряемые методом ОКТ у лиц с аномалиями рефракции [1][2][3][4][5][6]. Влияние изменений оптики глаза после кераторефракционных вмешательств на параметры ОКТ изучено пока недостаточно.…”

“…Хорошо известно, что характеристики оптической системы глаза, в первую очередь его длина, могут весьма существенно изменять количественные показатели ОКТ, особенно у лиц с аномалиями рефракции высокой степени [1][2][3][4][5][6]; роль других характеристик менее исследована. В ряде работ изучалось влияние кераторефракционных вмешательств на параметры ОКТ -толщину перипапиллярного слоя нервных волокон сетчатки (ПСНВС) [7][8][9][10], режедругих структур глазного дна [10].…”