Aims To investigate macular vascular integrity using optical coherence tomography angiography (OCTA) in patients undergoing vitrectomy for idiopathic epiretinal membrane (ERM) removal and to determine its association with structural and visual outcomes. Methods Forty-three patients with unilateral ERM who were followed for ≥6 months after surgery were included. Ophthalmological evaluations included best-corrected visual acuity (BCVA) and spectral-domain OCT (SD-OCT) before surgery and 6 months after surgery. We obtained en face OCTA images of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) for both eyes 6 months after ERM removal. We compared eyes with ERM to unaffected fellow eyes as controls and used interocular differences in the analyses. Results Compared with the fellow eyes, eyes with ERM after surgery had a lower parafoveal vascular density (VD) and a smaller foveal avascular zone (FAZ) area in both SCP and DCP (all p<0.001). Interocular differences in the FAZ area and parafoveal VD were correlated with preoperative and postoperative central foveal thicknesses (all p<0.05). In addition, interocular differences in macular vascular integrity had a tendency to be correlated with SD-OCT parameters of the inner retinal layers. Finally, greater interocular differences in the FAZ area and parafoveal VD of both plexuses were significantly associated with worse postoperative BCVAs (all p<0.05). Conclusions Assessing macular capillary plexuses via OCTA may be useful to quantify structural changes of the inner retinal layer and predict visual function in patients undergoing ERM removal surgery.

Aims To investigate the structural changes of the superficial capillary plexuses (SCP) and deep capillary plexuses (DCP) using optical coherence tomography (OCT) angiography (OCTA) in patients with idiopathic macular hole (MH) after surgery, determine the factors related to changes of macular capillary plexuses and evaluate its association with postoperative visual outcomes. Methods Thirty-three patients with unilateral MH who were followed for ≥6 months after surgery were included. Ophthalmologic evaluations included best corrected visual acuity (BCVA) and spectral-domain OCT before surgery and 6 months postsurgery. En face OCTA images were obtained for both eyes at 6 months postsurgery, and the postoperative foveal avascular zone (FAZ) area and parafoveal vascular density were identified. Results Compared with fellow eyes, eyes after MH surgery had a smaller FAZ area in both SCP and DCP (p<0.05 for all). The FAZ area was positively correlated with postoperative foveal thickness of the whole, inner and outer layers (p<0.05 for all). In the parafoveal region, eyes after MH surgery had a tendency to have lower parafoveal vascular density, particularly in DCP (p=0.019). The parafoveal vascular density in DCP was positively correlated with retinal thickness of the whole, inner and outer layers (p<0.05 for all). Correlations between BCVA and FAZ area in both SCP and DCP were significant 6 months after MH surgery (p<0.05 for all). Conclusion Assessment of macular capillary plexuses using OCTA may be useful for monitoring retinal structural and functional changes in MH.

Min CH, et al. Korean J Ophthalmol. 2019 Feb;34:e16. https://doi.org/10.3341/kjo.2019.0113

Realistic image synthesis based on deep learning is an invaluable technique for developing high-performance computer aided diagnosis systems while protecting patient privacy. However, training a generative adversarial network (GAN) for image synthesis remains challenging because of the large amounts of data required for training various kinds of image features. This study aims to synthesize retinal images indistinguishable from real images and evaluate the efficacy of the synthesized images having a specific disease for augmenting class imbalanced datasets. The synthesized images were validated via image Turing tests, qualitative analysis by retinal specialists, and quantitative analyses on amounts and signal-to-noise ratios of vessels. The efficacy of synthesized images was verified by deep learning-based classification performance. Turing test shows that accuracy, sensitivity, and specificity of 54.0 ± 12.3%, 71.1 ± 18.8%, and 36.9 ± 25.5%, respectively. Here, sensitivity represents correctness to find real images among real datasets. Vessel amounts and average SNR comparisons show 0.43% and 1.5% difference between real and synthesized images. The classification performance after augmenting synthesized images outperforms every ratio of imbalanced real datasets. Our study shows the realistic retina images were successfully generated with insignificant differences between the real and synthesized images and shows great potential for practical applications.

Kim YJ, et al. J Korean Med Sci. 2014 Dec;29(12):1699-1705. https://doi.org/10.3346/jkms.2014.29.12.1699

We conducted targeted next-generation sequencing (TGS) and/or whole exome sequencing (WES) to assess the genetic profiles of clinically suspected retinitis pigmentosa (RP) in the Korean population. A cohort of 279 unrelated Korean patients with clinically diagnosed RP and available family members underwent molecular analyses using TGS consisting of 88 RP-causing genes and/or WES with clinical variant interpretation. The combined genetic tests (TGS and/or WES) found a mutation in the 44 RP-causing genes and seven inherited retinal disease (IRD)-causing genes, and the total mutation detection rate was 57%. The mutation detection rate was higher in patients who experienced visual deterioration at a younger age (75.4%, age of symptom onset under 10 years) and who had a family history of RP (70.7%). The most common causative genes were EYS (8.2%), USH2A (6.8%), and PDE6B (4.7%), but mutations were dispersed among the 51 RP/IRD genes generally. Meanwhile, the PDE6B mutation was the most common in patients experiencing initial symptoms in their first decade, EYS in their second to third decades, and USH2A in their fifth decades and older. Of note, WES revealed some unexpected genotypes: ABCC6, CHM, CYP4V2, RS1, TGFBI, VPS13B, and WDR19, which were verified by ophthalmological re-phenotyping.