Purpose To compare retinal nerve fiber layer (RNFL) thickness profiles between preterm and full-term children and to investigate factors affecting the RNFL distribution in preterm children.Methods We performed Spectral domain optical coherence tomography (SD-OCT) peripapillary RNFL circular scan centered on the optic disc in 50 premature and 58 full-term children. RNFL thickness profiles were compared between preterm and fullterm children using a linear regression model. Among preterm patients in this study, 20 patients previously received laser treatment for severe retinopathy of prematurity (ROP).Results Global average, nasal, and superior disc RNFL thickness profiles were significantly smaller in preterm children (92.70 ± 16.57 μm, 56.02 ± 17.04 μm, and 108.74 ± 27.36 μm, respectively) compared with full-term children (101.63 ± 9.21 μm, P = 0.006, 69.14 ± 14.15 μm, Po0.001, and superior, 129.11 ± 18.14 μm, Po0.001, respectively). Multivariable analysis revealed that ROP stage was inversely correlated with nasal RNFL thickness (P = 0.010).Conclusions Our SD-OCT data demonstrate decreased global average, nasal, and superior disc RNFL thicknesses in preterm children. ROP stage was inversely correlated with nasal RNFL thickness. Further studies are needed to better understand the association between these structural changes and visual functions in preterm children.

Purpose The purpose of this study is to describe the clinical characteristics and treatment results of medial rectus muscle (MR) transection incurred during endoscopic sinus surgery. Methods This retrospective study included 16 patients with MR transection incurred during endoscopic sinus surgery between 1994 and 2015. The operative notes of the surgical procedure, the pattern of strabismus, the type of muscle injury, the type of corrective strabismus surgery, and the surgical outcomes were reviewed. Results Nine patients had partial resection of MR and seven patients had complete transection of MR, resulting from an injury incurred during endoscopic sinus surgery. Three of the nine patients with partial resection injury were initially diagnosed as complete resection and subsequently rediagnosed as partial resection in a review of the images during this study. Five of the nine patients with partial MR resection underwent only simple recession/resection surgery. Patients with complete MR transection underwent muscle transposition or globe fixation surgeries and often multiple operations were required. Conclusions The results of this study showed that the treatment strategies could vary depending on the nature of muscle injury. In cases with complete transection, muscle transposition or globe fixation surgeries are often required, with multiple operations. However, partial muscle resection with only simple recession/resection surgery shows a favorable outcome in many cases. The use of proper imaging techniques, a thorough review of the images with various planes, and close follow-up are important for determining the nature of the muscle injury.

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AimsThe aims of this study were to investigate the longitudinal change in lateral rectus (LR) muscle insertion after recession surgery, and to evaluate a relationship between insertion distance and postoperative amount of deviation.MethodsWe recruited 31 patients who underwent primary LR recession surgery with normal anterior segment structures. An AS-OCT scan of the LR muscle was performed at every visit. Data on sex, age, degree of deviation (prism diopter), and spur-LR insertion distance using AS-OCT were collected at preoperatively and postoperative months 1, 3, and 6. Spur-LR insertion was defined as the shortest distance between the insertion of the LR muscle and the scleral spur was measured using the caliper function in the AS-OCT software.ResultsThe mean distance of spur-LR insertion measured with AS-OCT was 5.5±0.7 mm preoperatively, and 11.1±0.9 mm at 1 month, 11.5±0.8 mm at 3 months, and 11.0±0.7 mm at 6 months postoperatively. There were significant differences in spur-LR insertion between postoperative 1 and 3 months, and between 3 and 6 months (generalized estimating equation, all P<0.001). The overall spur-LR insertion measurement has a significantly negative correlation with postoperative amount of deviation (Pearson's correlation, P=0.035, r=-0.218).ConclusionsAS-OCT is a useful instrument for understanding postoperative changes in EOM after tissue swelling subsides.

Aims To investigate the influence of preterm birth on the optic disc and retinal vessels by measurements of cup-to-disc (C/D) ratio and arteriole-to-venule (A/V) ratio. Methods Eighty-three eyes of 42 preterm births were included. In the age-and sexmatched control group, 83 eyes of 42 full-term births were used. Fundus color photographs were taken. ImageJ software was used to calculate C/D and A/V ratios from the fundus images.Results Fundus photographs were taken at 8.01 ± 2.22 years of age for the preterm group and 8.01 ± 2.13 years of age for the control group. The mean gestational age of the preterm group was 27 4 / 7 weeks (range, 24-34 weeks). The preterm group had significantly larger C/D ratio and smaller A/V ratio (mean ± standard deviation: 0.46 ± 0.12 and 0.59 ± 0.08, respectively) than the control group (0.36 ± 0.07 and 0.68 ± 0.07, respectively) after spherical equivalent refractive error was adjusted. Conclusions Preterm birth is significantly associated with larger C/D ratio and smaller A/V ratio. These findings show the effect of preterm birth on the development of optic disc and retinal vessel development.