The Influence of Low to Moderate Myopia on Retinal Nerve Fiber Layer as Assessed by Scanning Laser Polarimetry with Variable Corneal Compensator

Abstract

Purpose: To evaluate the influence of different degrees of myopia on retinal nerve fiber layer (RNFL) as measured by scanning laser polarimetry (SLP) with variable corneal compensator (VCC) in healthy eyes. Methods: One hundred and seventy-four healthy age-matched subjects with low to high myopic and emmetropic eyes underwent RNFL measurement by means of GDxVCC. The GDx parameters included in the analysis were: Temporal-superior-nasal-inferior thickness (TSNIT) average, Superior average, Inferior average, TSNIT standard deviation, Inter-eye symmetry, NFI, Symmetry, Superior ratio, Inferior ratio, Superior/nasal, Maximum modulation, Superior maximum, Inferior maximum, Ellipse modulation, Normalized superior area, Normalized inferior area, Ellipse standard deviation, Ellipse average. The mean value of each SLP parameter of myopic eyes was compared with the mean value of the same parameter of emmetropic eyes. Results: Mean myopia was 3.9 ± 1.5 dpt (range: –2 to –8.25 dpt). TNSIT average was higher in myopic group (p = 0.0111), together with Superior average (p = 0.0244), Symmetry (p < 0.0001) and Ellipse average (p = 0.0111). Two ratio parameters, Superior ratio and Inferior ratio, were higher in emmetropic eyes (p = 0.0179 in both cases). In both the myopic and the emmetropic group, all the SLP assessments of the RNFL fell within the normal range, according to the GDx database. Conclusions: Low to high myopia is not related to clinically relevant variations of SLP parameters, as assessed with GDx-VCC.

The effect of myopia on retinal nerve fibre layer measurement: a comparative study of spectral-domain optical coherence tomography and scanning laser polarimetry

“…Recently, Vetrugno et al found no correlation between RNFL thickness and SE in 86 myopic eyes (mean refractive error −3.9±1.5 D, range−2.00–−8.25 D) using GDx VCC. Of note, data on axial length and TSS were not mentioned in the study 9. It has been demonstrated that atypical retardation patterns (ARPs) are associated with myopia and can cause inaccurate measurement 17.…”

“…Using OCT-1, Hoh et al did not find any significant association between RNFL thickness and axial length/SE,5 while recent studies based on OCT 3 (StratusOCT; Carl Zeiss Meditec Inc, Dublin, CA, USA; the time domain technology) have reported a negative relationship between RNFL thickness and axial length 6–8. However, no such evident correlation between RNFL and myopia was found in a recent study based on SLP with variable corneal compensator (GDx VCC) 9. Thus, the association between RNFL thickness and myopia is controversial.…”

Evaluating Glaucomatous Retinal Nerve Fiber Damage by GDx VCC Polarimetry in Taiwan Chinese Population

“…19 In addition, low-to-high myopia is not related to clinically relevant variations of the parameters measured with SLP, as assessed with the GDx VCC device. 20 Several studies have evaluated the diagnostic capability of GDx VCC in glaucoma detection, especially at its early stages. [4][5][6][7] Weinreb et al 4 showed that the parameter with the largest AROC (0.83) for discriminating 54 glaucomatous eyes (average MD: 6.49 dB) from 40 healthy eyes was the average RNFL thickness within the superior quadrant.…”

Assessment of optic disc parameters among healthy adult Malays by Heidelberg Retinal Tomograph II

“…In a recent study comparing between myopic and emmetropic eyes, Vetrugno et al found thicker superior and inferior RNFL and a thicker temporal RNFL, also by using a scanning laser polarimetry. 40 These findings showed that optic nerve parameters vary greatly with the methods used and the degrees of myopia.…”