The eye is provided with immune protection against pathogens in a manner that greatly reduces the threat of inflammation-induced vision loss. Immune-mediated inflammation and allograft rejection are greatly reduced in the eye, a phenomenon called ‘immune privilege’. Corneal tissue has inherent immune privilege properties with underlying three mechanisms: (1) anatomical, cellular, and molecular barriers in the cornea; (2) an immunosuppressive microenvironment; and (3) tolerance related to regulatory T cells and anterior chamber-associated immune deviation. This review describes the molecular mechanisms of the immunosuppressive microenvironment and regulatory T cells in the cornea that have been elucidated from animal models of ocular inflammation, especially those involving corneal transplantation, it also provides an update on immune checkpoint molecules in corneal and systemic immune regulation, and its relevance for dry eye associated with checkpoint inhibitor therapy.

We examined the effects of different ophthalmic viscosurgical devices (OVDs) and suction flow rates during phacoemulsification on the amount of ultrasound power used and damage to the corneal endothelium. In total, 48 eyes of 24 patients who underwent phacoemulsification and intraocular lens insertion with different OVD settings in the left and right eye between February and August 2018 were examined retrospectively from medical records. Each of the following types of OVDs was used in either the right or left eye of each patient: a viscoadaptive OVD (V group) or a combination of dispersive and cohesive OVDs (soft-shell technique; S group). There was no significant difference in the lens nucleus hardness between the two groups. A 2.4 mm transconjunctival scleral incision was made, and phacoemulsification was performed by the same surgeon. The cumulative dissipated energy (CDE) and ultrasound time intraoperatively were compared between the two groups. The CDE was significantly larger in the V group (9.9 ± 4.6) than the S group (6.4 ± 3.0; p=0.006). The reduction rate of the endothelial cell density at the center of the cornea was significantly higher in the V group (4.1% ± 6.7%) than the S group (0.3% ± 4.5%; p=0.03) at 1 week postoperatively. Both groups had a good postoperative course. There was less corneal endothelial damage with the soft-shell technique combined with a normal flow setting than the viscoadaptive OVD combined with a low flow setting.

Capsular stabilization devices were evaluated in a zonular fiber defect model using the slit side view (SSV) system to confirm their utility for capsular stabilization during phacoemulsification. A zonular fiber defect model was made by cutting Zinn’s zonule under observation with a slit lamp microscope in a porcine eye. Phacoemulsification was performed, and the movement of the lens capsule and the depth of the anterior chamber were observed using the SSV in three groups: control group: no surgical instruments used, CE group: a capsule expander was inserted, and CTR group: a capsular tension ring was inserted. In the control group, the equator of the lens was unstable and was easily suctioned to the port of the ultrasound handpiece. The lens capsule was stable in both in the CE and CTR groups. In the CTR group, the equator responsible for the zonular rupture also returned and closed true to its original position. The utility of the capsular stabilization devices in this zonular fiber defect model was confirmed with the SSV system.

Background: We compared our initial experience in terms of visual outcomes, operation time and complications from two different intrascleral intraocular lens (IOL) fixation techniques: T-fixation; and flanged IOL fixation.Methods: Patients who underwent scleral fixation of an IOL between October 2017 and December 2018 were examined retrospectively. Intraoperative time for fixation steps, corneal endothelial cell density (ECD) reduction rate and intraoperative/postoperative complications were compared between T-fixation (Group T, n = 4) and flanged IOL fixation (Group F, n = 6).Results: Patients ranged in age from 73.7 ± 13.0 years. Intraoperative time was significantly longer for Group T (27.5 ± 9.7 min) than for Group F (13.0 ± 3.8 min; P=0.03, Mann-Whitney U-test). Intraoperative complications included iris damage from the 30-G needle in 2 eyes in Group F. Postoperative complications included iris capture by the IOL in 1 eye in Group F. No incidents of postoperative retinal detachment or IOL dislocation were identified. The ECD reduction rate showed no significant difference between the two groups.Conclusions: Both techniques showed favorable surgical outcomes. Flanged IOL fixation might be superior because of the shorter intraoperative time, but might initially be technically difficult because of the need to perform angled sclerotomy with a 30-G needle to avoid iris injury.

Cilioretinal artery occlusion (CLRAO) is a rare disease. Here, we report the case of a 70-year-old man with nonarteritic cilioretinal artery occlusion alone. The patient was allergic to fluorescein. Therefore, we followed the retinal circulation with optical coherence tomography angiography (OCTA). OCTA at 40 days postonset showed partial improvement in the retinal circulation.

Purpose: To evaluate the impact of dominant eye involvement on binocular visual function and vision-related quality of life (VR-QoL), and to determine the monocular metamorphopsia threshold associated with binocular symptom perception in patients with unilateral epiretinal membrane (ERM). Methods: This prospective single-center study included patients with unilateral ERM. Ocular dominance was determined using the hole-in-card test. Best-corrected visual acuity (BCVA), monocular and binocular metamorphopsia measured with M-CHARTS, aniseikonia, stereopsis, and VR-QoL using VFQ-25 were evaluated. Patients were classified according to whether ERM involved the dominant or non-dominant eye. Results: Sixty-eight patients were enrolled, including 35 patients in the non-dominant eye group and 33 in the dominant eye group. Horizontal binocular metamorphopsia scores were significantly higher in the dominant eye group than in the non-dominant eye group (p < 0.05). No significant differences were observed in BCVA, stereopsis, or VFQ-25 composite scores between the groups. Binocular metamorphopsia scores significantly correlated with VFQ-25 composite scores only in the dominant eye group. Receiver operating characteristic (ROC) analysis demonstrated that a mean monocular metamorphopsia score of 0.55 was the optimal threshold for binocular symptom perception in eyes with dominant eye involvement (AUC = 0.66; 95% CI, 0.48–0.85) Conclusion: Dominant eye involvement was associated with greater binocular metamorphopsia and a stronger association between metamorphopsia and VR-QoL in unilateral ERM. A mean monocular metamorphopsia score of ≥ 0.55 may represent a preliminary threshold associated with binocular symptom perception and may help guide future clinical assessment.