Purpose: To elucidate the clinical and epidemiologic characteristics of optic neuritis in Japan. Design: Multicenter cross-sectional, observational cohort study. Participants: A total of 531 cases of unilateral or bilateral noninfectious optic neuritis identified in 33 institutions nationwide in Japan. Methods: Serum samples from patients with optic neuritis were tested for antieaquaporin-4 antibodies (AQP4-Abs) and antiemyelin oligodendrocyte glycoprotein antibodies (MOG-Abs) using a cell-based assay and were correlated with the clinical findings. Main Outcome Measures: Antibody positivity, clinical and radiologic characteristics, and visual outcome. Results: Among 531 cases of optic neuritis, 12% were AQP4-Ab positive, 10% were MOG-Ab positive, 77% were negative for both antibodies (double-negative), and 1 case was positive for both antibodies. Pretreatment visual acuity (VA) worsened to more than a median 1.0 logarithm of the minimum angle of resolution (logMAR) in all groups. After steroid pulse therapy (combined with plasmapheresis in 32% of patients in AQP4-Abepositive group), median VA improved to 0.4 logMAR in the AQP4-Abepositive group, 0 logMAR in the MOG-Abepositive group, and 0.1 logMAR in the double-negative group. The AQP4-Abepositive group showed a high proportion of females, exhibited diverse visual field abnormalities, and demonstrated concurrent spinal cord lesions on magnetic resonance imaging (MRI) in 22% of the patients. In the MOG-Abepositive group, although posttreatment visual outcome was good, the rates of optic disc swelling and pain with eye movement were significantly higher than those in the AQP4-Abepositive and double-negative groups. However, most cases showed isolated optic neuritis lesions on MRI. In the double-negative group, 4% of the patients had multiple sclerosis. Multivariate logistic regression analysis of all participants identified age and presence of antibodies (MOG-Ab and AQP4-Ab) as significant factors affecting visual outcome. Conclusions: The present large-scale cohort study revealed the clinicoepidemiologic features of noninfectious optic neuritis in Japan. Antieaquaporin-4 antibodyepositive optic neuritis has poor visual outcome. In contrast, MOG-Ab positive cases manifested severe clinical findings of optic neuritis before treatment, but few showed concurrent lesions in sites other than the optic nerve and generally showed good treatment response with favorable visual outcome. These findings indicate that autoantibody measurement is useful for prompt diagnosis and proper management of optic neuritis that tends to become refractory.

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The high affinity of α-blockers for α(1)-adrenoreceptors is important in the analysis of the mechanism of IFIS. However, IFIS should not be attributed to long-term binding with receptors alone; the drug-melanin interaction causing dilator muscle atrophy is probably the other important factor in the mechanism of IFIS.

We observed the histopathological changes of retinal ganglion cells (RGCs), optic disc, and optic nerve in rabbit with advanced retinitis pigmentosa (RP). Wild-type (WT) and rhodopsin transgenic (Tg) of RP rabbits were used at age 24 months. Light and electron microscopy were used to observe the retina, optic disc, and optic nerve. RGCs were also confirmed by immunofluorescent staining with a TUJ-1 monoclonal antibody. In addition to the rod and cone degeneration, we observed the astrocyte infiltration of the optic disc due to the damage of small RGCs and nerve fibres and atrophy of small optic nerve fibres. They subsequently lead to the optic disc excavation and atrophy of the optic nerve. Consequently, our histopathological study clarified that not only the outer retina but also the inner retina, the optic disc, and the optic nerve were also affected in the late stages of RP rabbit.

These results indicate that latanoprost and PGE2 relaxed rabbit ciliary artery to different degrees. The relaxation provoked by latanoprost was not dependent on endothelium and was not caused by intrinsic PG, CGRP or nitric oxide. The mechanism of this relaxation is not yet clear.

<b><i>Introduction:</i></b> Micropulse transscleral cyclophotocoagulation (MP-TSCPC) is a method for intraocular pressure (IOP) reduction in patients with glaucoma; however, the specific mechanisms underlying its ability to reduce IOP remain unclear. We therefore investigated the morphological changes and mechanisms of IOP reduction after MP-TSCPC. <b><i>Methods:</i></b> The right eyes of 4 pigmented rabbits were treated with MP-TSCPC with power setting corresponding to those used in glaucoma patients (1 power: 2,000 mW; time: 160 s; duty cycle: 31.3%). Power settings of 1, 1/8, 1/16, and 1/32 power were applied to the right eyes. The left eyes were used as controls. A light microscope and electron microscope were used to observe morphological findings after 1 week of MP-TSCPC. IOP and IOP reduction rate were compared before and after MP-TSCPC application on days 1, 3, and 5, and at 1 week. <b><i>Results:</i></b> In the pre-MP-TSCPC, IOP was 16.7 ± 0.6 mm Hg. The IOP of rabbit treated with the 1 power was 3 mm Hg, with an IOP reduction rate of 80%; however, the eyes developed phthisis bulbi. The IOP was 7.0 ± 0.0 mm Hg 1 week after MP-TSCPC (IOP reduction rate: 59%) in rabbit treated with the 1/8 power. Reduction in IOP was observed, but there was significant tissue invasion to the ciliary body. The IOP was 10.3 ± 0.6 mm Hg (IOP reduction rate: 40%) 1 week after MP-TSCPC in rabbit treated with the 1/16 power, which was more effective to reduce IOP than that with the 1/8 power. Tissue invasion to the ciliary body was negligible, nonpigmented epithelial cells of the pars plicata were damaged, basal infoldings were destroyed, and repair was accompanied by proliferating tissue. No IOP reduction or tissue change was observed in rabbit treated with the 1/32 power. <b><i>Conclusion:</i></b> A potential mechanism for IOP reduction in pigmented rabbits is aqueous humor transport dysfunction due to damage to the nonpigmented epithelial cells of the pars plicata and destruction of basal infoldings. The power of MP-TSCPC was consistent with both morphological changes and IOP reduction.

The changes in the pupil light response and amplitude of the ERG could be used to predict the state of retinal degeneration in the Tg rabbit.

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