Genetic polymorphisms in the promoter of the interferon gamma receptor 1 gene are associated with atopic cataracts.

PURPOSE: Previous reports have shown genetic predisposition for atopic dermatitis (AD). Some of the severe complications of AD manifest in the eye, such as cataract, retinal detachment, and keratoconjunctivitis. This study was conducted to examine the genetic association between the atopy-related genes and patients with ocular complications (ocular AD). METHODS: Seventy-eighty patients with ocular AD and 282 healthy control subjects were enrolled in an investigation of the association between the atopy-related genes (FCERB, IL13, and IFNGR1) and ocular AD. Genetic association studies and functional analysis of single nucleotide polymorphisms (SNPs) were performed. RESULTS: The -56TT genotype in the IFNGR1 promoter region was significantly associated with an increased risk of ocular AD under recessive models (chi(2) test, raw P = 0.0004, odds ratio 2.57). The -56TT genotype was more common in atopic cataracts. A reporter gene assay showed that, after stimulation with IFN-gamma, the IFNGR1 gene promoter construct that contained the -56T allele, a common allele in ocular AD patients, manifested higher transcriptional activity in lens epithelial cells (LECs) than did the construct with the -56C allele. Real-time PCR analysis demonstrated higher IFNGR1 mRNA expression in the LECs in atopic than in senile cataracts. iNOS expression by IFNGR1-overexpressing LECs was enhanced on stimulation with IFN-gamma and LPS. CONCLUSIONS: The -56T allele in the IFNGR1 promoter results in higher IFNGR1 transcriptional activity and represents a genetic risk factor for atopic cataracts.

A new non-trocar system for 25-gauge transconjunctival pars plana vitrectomy.

PURPOSE: To introduce a new non-trocar system for 25-gauge transconjunctival pars plana vitrectomy (PPV). DESIGN: Study of a new surgical instrument. METHODS: This new non-trocar system for 25-gauge transconjunctival PPV consists of a contact lens ring featuring four projections containing 1.0-mm diameter holes located 3.0 mm from the ring edge, a wedge-shaped 25-gauge infusion cannula, and two plugs. RESULTS: The ring is fixed with 7-0 silk sutures at the 3- and 9-o'clock positions on the limbus. Using the 25-gauge needle, three conjunctival and scleral incisions (n = 3) are made at the projection holes located inferotemporally, superonasally, and superotemporally. No intra- or postoperative complications were encountered in 14 patients treated by this non-trocar 25-gauge transconjunctival PPV. CONCLUSION: Using the system introduced here, 25-gauge transconjunctival PPV can be performed without suturing sclerotomies and without intra- or postoperative complications.

The presence of Propionibacterium spp. in the vitreous fluid of uveitis patients with sarcoidosis.

PURPOSE: An immunological reaction to a bacterial antigen, such as Mycobacterium tuberculosis or Propionibacterium spp., is suspected to be an initial mechanism in the disorder known as sarcoidosis. We investigated whether or not P. acnes, P. granulosum or M. tuberculosis are present in the vitreous fluid of eyes suffering from uveitis with sarcoidosis. METHODS: Using polymerase chain reaction, we analysed the presence of P. acnes, P. granulosum and/or M. tuberculosis DNA in vitreous samples taken from six eyes with sarcoidosis and six control eyes. RESULTS: Among the six uveitis eyes with sarcoidosis, we detected P. acnes DNA in two eyes, P. granulosum DNA in four eyes, and both P. acnes and P. granulosum DNA in one eye, but no Propionibacterium spp. in the control eyes. M. tuberculosis DNA was not present in any of the patient or control eyes. CONCLUSIONS: This is the first report indicating the presence of Propionibacterium spp. and/or its DNA in the vitreous fluid of sarcoidic eyes with uveitis. This, therefore, supports the idea that Propionibacterium spp. are involved in the aetiology of uveitis in sarcoidosis.

[Low power transpupillary thermotherapy of choroidal neovascularization].

PURPOSE: To assess the effectiveness of low power transpupillary thermotherapy (TTT) for choroidal neovascularization (CNV). METHOD: We performed TTT on 55 eyes of 55 patients with subretinal CNV between April 2001 and December 2002, and observed them after therapy for more than 6 months. The laser power ranged from 80 to 320 mW when the spot size was 3 mm. We evaluated visual acuity, subretinal fluid (SRF), and CNV size. RESULTS: Visual acuity improved by 2 lines or more in 16 eyes (29%), was unchanged in 19 eyes (35%), and decreased in 20 eyes (36%). SRF decreased in 30 eyes (54%), was unchanged in 13 eyes (24%), and increased in 12 eyes (22%). CNV diminished in 33 eyes (60%), was unchanged in 10 eyes (18%), and became enlarged in 12 eyes (22%). CONCLUSIONS: Low power TTT can be an effective treatment for subgroups of patients with subfoveal CNV.

Platelet aggregates in various stages of diabetic retinopathy: evaluation using the particle-counting light-scattering method.

AIMS: To investigate the possible correlation between platelet aggregation and the severity of diabetic retinopathy using the light-scattering method. METHODS: Using a light-scattering platelet aggregometer, we measured spontaneous platelet aggregation in 86 diabetics with retinopathy of varying severity and 30 healthy volunteers (controls). Platelet aggregates were classified as small, medium, and large according to their light intensity; patients were grouped based on the severity of retinopathy. In each patient group, we recorded for 10 min the total light intensities emitted by each aggregate size in the area under the curve (AUC). Then, we compared the AUC of each level of retinopathy severity with the controls and determined the correlation between the AUC of each aggregate size and each severity level. RESULTS: Of the 86 diabetics, 22 had no apparent retinopathy (NAR), 13 had mild nonproliferative diabetic retinopathy (NPDR), 17 had moderate NPDR, 12 had severe NPDR, and 22 had proliferative diabetic retinopathy (PDR). While the NAR group manifested significantly more small aggregates than the controls (20.5 x 10(6) versus 8.3 x 10(6) a.u., p=0.024), none of the other groups showed a significant increase in aggregates of any size. In the AUC of large aggregates, there was a weak-positive correlation with the severity of retinopathy (r=0.255, p=0.018); in the AUC of small and medium aggregates, there was no correlation. CONCLUSION: Although we did not find a significant correlation between platelet aggregation and the severity of diabetic retinopathy, our pilot study did detect some tendencies. Further studies on larger populations are underway to determine whether these tendencies are real.

Comparative effect of antiplatelet therapy in retinal vein occlusion evaluated by the particle-counting method using light scattering.

PURPOSE: To evaluate platelet aggregation in patients with retinal vein occlusion (RVO) by the light-scattering method and compare the effects of three antiplatelet drugs on aggregate formation. DESIGN: Prospective, nonrandomized, interventional clinical trial. METHODS: (1) Platelet aggregation was measured in 42 patients with untreated branch RVO (BRVO), 26 patients with central RVO (CRVO), and 30 healthy control subjects using a light-scattering platelet aggregometer. Platelet aggregates were classified as small, medium, and large according to light intensity. Total light intensities of each aggregate size were compared between BRVO, CRVO, and control subjects. (2) In 33 patients with RVO, platelet aggregation before and 2 weeks after the administration of ticlopidine, beraprost, or aspirin were compared. RESULTS: (1) There was a statistically significant difference (P = 0.0073) between the control subjects (8.3 x 10(6) a.u.) and CRVO patients (22.9 x 10(6) a.u.) with respect to small aggregates. There was no statistically significant difference with respect to medium and large aggregate formation between the control subjects and either patient group. (2) Compared with aggregates formed in the absence of antiplatelet drugs, ticlopidine significantly inhibited only the formation of small aggregates and beraprost that of all sizes; aspirin did not significantly inhibit the formation of any aggregate sizes. CONCLUSIONS: Increase in small platelet aggregates may be attributable to RVO pathogenesis. Beraprost and ticlopidine appear to inhibit small aggregate formation in RVO patients and may represent effective antiplatelet treatments. The light-scattering method is useful to investigate the pathogenesis of RVO and the effects of antiplatelet drugs.