Aconite induced myelo-optic neuropathy in a rabbit model.

Aconite is a common remedy of herb doctors and is widely used in the Far East. Clinical aspects of the visual disturbance produced by this drug have been described, but little is known about its pathology. Tinctura aconiti (0.6 mg of total alkaloid/kg 2x) was administered intraperitoneally in rabbits to evaluate its toxic effects on the visual system. The alteration in the visual evoked potential following aconite injection consisted of a delay in the onset and peak latency. Histopathologically, there were damages to the myelin sheath of the visual pathway, spinal cord and peripheral nerves. These findings suggest that aconite may cause primarily myelo-optic neuropathy.

Conjunctival pigmentation after 23-gauge microincisional vitrectomy surgery.

AIM: To investigate cases with conjunctival pigmentation originating from sclerotomy sites after 23-gauge microincisional vitrectomy surgery (MIVS). METHODS: This is a retrospective study comprised of 185 eyes from 185 consecutive patients who underwent 23-gauge MIVS. The authors investigated the incidence and the clinical factors associated with conjunctival pigmentation, including indication of vitrectomy and surgical procedures. RESULTS: Eight eyes (4.3%) from 185 eyes showed conjunctival pigmentation after surgery within 7 days postoperatively. Light microscopic examination of excised tissue showed infiltration of abundant dark brownish colored melanophages with surrounding scattered, finely granular, melanin pigments. C3F8 gas tamponade (OR, 9.4; 95% CI, 1.9-44.5; P=0.005) was significantly associated with conjunctival pigmentation. The mean surface area (21.26±2.21 mm(2)) of three eyes with C3F8 tamponade was significantly larger than that of five eyes (2.51±0.73 mm(2)) without tamponade (P=0.025). Neither leakage nor hypotony was found. CONCLUSIONS: Intraocular melanin pigments could prolapse through the sclerotomy site and cause conjunctival pigmentation after 23-gauge MIVS. Thus, preoperative warning is necessary in patients with 23-gauge MIVS.

Combined 23-gauge microincisonal vitrectomy surgery and phacoemulsification with AcrySof toric intraocular lens implantation: a comparative study.

AIM: To compare AcrySof toric intraocular lens (IOL) and non-toric IOL in patients who had combined 23-gauge microincisional vitrectomy surgery (MIVS) and phacoemulsification for vitreoretinal diseases and cataract with pre-existing corneal astigmatism. METHODS: This is a prospective comparative study comprised of 30 patients (30 eyes) who had combined 23-gauge MIVS and phacoemulsification for vitreoretinal diseases and cataract with pre-existing regular corneal astigmatism greater than 1 diopters (D). In all, 15 eyes had AcrySof toric IOL (Alcon Laboratories) and 15 eyes had non-toric IOL (Akreos AO MI60; Bausch & Lomb) implantation. Main outcome measures were uncorrected visual acuity (UCVA), refractive cylinder, surgically induced astigmatism (SIA), and IOL misalignment during 6 months. RESULTS: The mean UCVA of the toric IOL group was better than the non-toric IOL group at postoperative months 1, 3, and 6 (P<0.001, respectively). The mean absolute residual refractive cylinder of the toric IOL group at postoperative week 1, and months 1, 3, and 6 was less than the non-toric IOL group (P=0.008, <0.001, <0.001, and <0.001, respectively). There was no difference in the mean SIA between the two groups (P>0.05, respectively). The mean toric IOL axis rotation was 3.52 ± 2.75°, which was within 5° in 66.7% of the toric IOL group and within 10° in 100%. CONCLUSIONS: Combined 23-gauge MIVS and phacoemulsification with AcrySof toric IOL implantation is an effective method of correcting vitreoretinal diseases and cataract and pre-existing corneal astigmatism, and the toric IOL showed good rotational stability, even in vitrectomized eyes for 6 months.

The protection of the retina from ischemic injury by the free radical scavenger EGb 761 and zinc in the cat retina.

We investigated the effects of a free radical scavenger (EGb 761) and zinc in experimentally induced ischemic injury in the cat retina. Total retinal ischemia for 90 min was produced in the left eyes of 40 cats by raising intraocular pressure. In group 1, 10 cats were used as control. The free radical scavenger (EGb 761, 100 mg/kg) in group 2 (10 cats) and zinc chloride (250 microg/kg) in group 3 (10 cats) were administered intravenously at the end of ischemia. In group 4, both EGb 761 (100 mg/kg) and zinc chloride (250 microg/kg) were injected into 10 cats. ERG and a histologic study were performed 1 h, 1 day, 3 days, 1 week and 2 weeks after ischemia. The amplitude of the ERG b-wave was 62.73+/-0.32, 84.31+/-6.10, 83.65+/-12.23 and 102.4+/-14.27%, and the summed amplitude of oscillatory potentials was 66.16+/-16.42, 99.44+/-14.92, 95.45+/-6.42 and 99.62+/-12.32% in each group 2 weeks after ischemia. There was no significant effect in animals that received zinc alone (group 3) by the end of 1 week but some additive effect in combining EGb 761 and zinc chloride (group 4) 1 h after ischemia. These findings suggest that the free radical scavenger EGb 761 may efficiently protect the retina from ischemic injury and zinc may have an additive effect when combined with a radical scavenger.