Session Title: Free Paper Session 25: Imaging IV
Session Date/Time: Sunday 10/09/2017 | 10:00-11:30
Paper Time: 11:00
Venue: Room 113
First Author: : A.Barata PORTUGAL
Co Author(s): : I. Leal F. Sousa F. Teixeira F. Pinto
To investigate if hydroxychloroquine (HCQ) patients with apparent no HCQ outer retinal toxicity will show lower retinal thickness in inner layers as compared to healthy controls.
Retrospective study of 43 patients (86 eyes) evaluated at Hospital de Santa Maria (Lisbon, Portugal) for HCQ macular toxicity with spectral-domain OCT (SD-OCT, Heidelberg Engineering, Heidelberg, Germany) between January-April 2016 and with no OCT signs of HCQ maculopathy that were subdivided into two groups: 1) no blunting of the foveal contour (foveal splaying), 2) with foveal splaying. Age and sex-matched controls were used for comparison. Automated retinal layer segmentation at the centre of fovea and at a radius of 3 (parafoveal) to 6mm (perifoveal) from the superior, inferior, temporal and nasal sectors (ETDRS grid) was performed. Cases with image quality less then 20 were excluded. Age and sex-matched controls were used for comparison. Statistical analysis using two sample t-test was made to calculate significant results between groups with 95% confidence interval.
centre macular and internal retinal layers thickness in all parafoveal sectors, particularly in the retinal nerve fibre (RNFL) and ganglion cell layer (GCL), was statistically reduced when compared to control group (p<0.05) and differed between group 1 and 2. RNFL thickness was also reduced in all perifoveal sectors but temporal sector (p<0.05) and inner plexiform layer and inner nuclear layer thickness showed only significant reduction in foveal and nasal parafoveal sector (p<0.05) in HCQ eyes. No significant differences in outer layers was observed between groups.
Small changes in inner retinal layers thickness have been described with HCQ use and conflicting correlation with HCQ toxicity is present in the literature. This study supports that inner retina at the fovea and parafovea is thinner in patients with no outer retinal OCT signs of HCQ toxicity. Further investigation is needed to assess if an inner retinal thickness reduction threshold measured by automatic segmentation could serve as valuable tool for identifying patients with increased risk of HCQ maculopathy.