Effect of multizone refractive multifocal contact lenses on the Cirrus HD OCT retinal measurements.
BACKGROUND
Simultaneous vision multifocal contact lenses are widely used to alleviate the symptoms of presbyopia. These contact lenses create simultaneous retinal images due to the incoming light distribution being divided into two or more focuses. Our aim was to evaluate whether the multizone refractive multifocal contact lenses affect the measurements of the retinal nerve fibre layer (RNFL) and macular thickness using optical coherence tomography (OCT).


METHODS
In this cross-over study, 30 eyes of 30 subjects with a mean age of 50.42 ± 7.82 years were fitted with multizone refractive multifocal contact lenses. Using the RNFL Thickness Analysis mode of the Cirrus HD (Carl Zeiss, Meditec, Dublin, CA, USA) OCT, the average, superior, nasal, inferior, temporal and 12 o'clock-hour retinal nerve fibre layer thicknesses were obtained. In Macular Thickness Analysis mode of Cirrus HD OCT, the average cube thickness, macular cube volume, central subfield thickness, inner and outer macular thickness (superior, inferior, nasal and temporal area) were obtained. Measurements were performed with and without contact lenses.


RESULTS
Statistically significant differences were not found in RNFL thickness at any of the studied areas and for 12 o'clock-hour sectors analysed (p > 0.07). The mean macular volume was 9.86 ± 0.30 mm(3) and 9.87 ± 0.27 mm(3) with and without multifocal contact lenses, respectively (p = 0.38). There were no statistically significant differences in average macular thickness or macular thickness of areas analysed between the measurements with and without multifocal contact lenses (p > 0.09). The signal strength was higher than seven for all scans, and differences were not found in the mean of signal strength between the measurements with and without contact lenses.


CONCLUSIONS
The results of this study suggest that the assessed multizone refractive multifocal contact lens does not affect the retinal nerve fibre layer and macular thickness measurements using Cirrus HD OCT.
Optometry Research Group, Optics Department, University of Valencia, Spain. david.madrid@uv.es
David
D
Madrid-Costa
Leticia
L
Isla-Paradelo
Santiago
S
García-Lázaro
César
C
Albarrán-Diego
Javier
J
Ruiz-Alcocer
D003261:Contact Lenses; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D011305:Presbyopia / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation*; D012029:Refraction, Ocular / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods; D014792:Visual Acuity / Q000502:physiology*