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Yi-Zhong Wang, Yu-Guang He, Paulina Mejia, Michael B Bartlett, Song Zhang, Karl G Csaky; Association of Visual Function (VF) with Central Subfield Thickness (CSFT) and Photoreceptor Outer Segment Length (CSFOS) in 3-Month Treatment of Diabetic Macular Edema (DME). Invest. Ophthalmol. Vis. Sci. 2018;59(9):3442. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
Previous studies (DRCRnet, Ophthalmology 2007 114:525) showed a modest correlation between OCT center thickness and visual acuity (VA) in DME, but recent studies suggest that OS length may be more directly related to VF in DME (Forooghian, et al. Retina 2010 30:63). Here we examined the relationship between VF and CSFT as well as CSFOS in 3-month DME treatments.
Thirty-two patients with DME under active treatment were recruited for the Diabetic Retinopathy And the MyVisionTrack® (mVT®) App (DRAMA) study (NCT01728883). Among them, 30 had prior treatments (mean±SD prior-treatment duration: 39±41 months). The study eye had VA 20/100 or better at enrollment. Besides the standard care, ETDRS VA, Pelli-Robson contrast sensitivity (CS), shape discrimination hyperacuity (SDH), and SD-OCT 31-line macular volume scan were obtained at the initial and 3-month study visits. OCT volume scans were segmented with manual adjustment using Spectralis (ver. 1.9.10) to obtain CSFT, and the segmentation results were exported to MATLAB to obtain CSFOS measures. Clinically significant change of CSFT in 3 months was defined by a change of ≥ 8 mm (Comyn et al. IOVS 2012 53:7754). The association of VF with CSFT and CSFOS was assessed using Pearson correlation analysis.
At the initial study visit, VA (logMAR) was significantly correlated with CSFT (r=0.51, p<0.003). In addition, VA, CS and SDH (logMAR) were significantly correlated with CSFOS (r=-0.35, p<0.05; r=0.49, p<0.004; and r=-0.46, p<0.008, respectively). The average number of treatments in 3 months was 2.1±1.2 (65% anti-VEGF). At 3 months, 17 patients showed reduction of CSFT, and 11 showed worsening, while 4 showed no change. SDH change at 3 months was significantly correlated with the change of CSFT (r=0.41, p<0.018) and the change of CSFOS (r=-0.44, p<0.014). VA (logMAR) showed a trend toward improvement with the increase of CSFOS (r=-0.30, p=0.104).
These results support that OS disruption may be more directly related to VF loss in DME. The results also suggest that hyperacuity may be more sensitive than VA and CS to the change of edema and/or OS length. Further studies are needed to establish a multivariable model for better understanding of the structural and functional relationship and predicting DME treatment outcomes.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
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