Abstract
Purpose :
Previous studies indicated that changes in the spectral-domain optical coherence tomography (SD-OCT)-measured thicknesses of retinal ganglion cell (RGC)-related retinal layers, i.e., structure, generally preceded those in the standard automated perimetry (SAP)-measured sensitivity, i.e., function, in the early stage of glaucoma. Though cross-sectional studies showed that both the structure and function declined along with aging in normal eyes, there is a paucity of information on the structure-function relationship associated with the aging process. We compared aging changes of SAP sensitivities and SD-OCT-measurement results in the corresponding retinal areas in normal eyes.
Methods :
Humphrey Field Analyzer 24-2 SITA-S program tests (HFA-24-2) and parapapillary and macular SD-OCT measurements using OCT-2000 (Topcon, Japan) were done every 3 months for 3 years in 76 eyes of 38 normal subjects aged 51.6 ± 12.8 (SD) years. Change rates of the average sensitivities of the all HFA 24-2 points, that of the central 4 points, circumpapillary retinal nerve fiber layer thickness (CpRNFLT) and ganglion cell-inner plexiform layer thickness (GCIPLT) in 4 regions with 2° of visual angle corresponding to the 4 central points (GCIPLTcentral4) were analyzed using the linear mixed model adjusting for the age, baseline values, axial length (AL) and disc area.
Results :
Aging-related change rate in the average sensitivity of the all HFA 24-2 points corresponding to CpRNFLT and that of the 4 central points corresponding to GCIPLTcentral4 adjusted for the above covariates were -0.19 and -0.20 dB/year (P=0.015,<0.001), and -38 and -92 (1/Lambert)/year (P<0.001), respectively, with higher age (P=0.019~0.003) and baseline sensitivity (P=0.017~<0.001) associating with higher change rate. On the other hand, no significant aging-related changes could be detected in CpRNFLT or GCIPLTcentral4, except that higher age associated with a small increase in the decline rate (0.002m/year, P=0.0007) of CpRNFLT.
Conclusions :
As far as the current normal subjects were concerned, aging-related change could not be detected in CpRNFLT and GCIPLT central4 in 3 years, while SAP sensitivities in the corresponding retinal regions showed significant decline, suggesting that structure-function relationship in the physiological aging process may be different from that in the early stage-glaucoma.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.