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In plants, viruses induce an RNA-mediated defense that is similar to posttranscriptional gene silencing (PTGS) of transgenes. Here we demonstrate with potato virus X (PVX) that PTGS operates as a systemic, sequence-specific defense system. However, in grafting experiments or with movement defective forms of PVX, we could not detect systemic silencing unless the 25 kDa viral movement protein (p25) was made nonfunctional. Investigation of p25 revealed two branches to the PTGS pathway that converge in the production of 25 nucleotide RNAs corresponding to the target RNA. One of these branches is unique to virus-induced PTGS and is not affected by p25. The second branch is common to both virus- and transgene-induced PTGS, is blocked by p25, and is likely to generate the systemic silencing signal.

Purpose: The purpose of the study is to determine the efficacy and safety of Mitomycin C (MMC) augmented slit-lamp needle revision of failed filtration surgery., Methods: The authors retrospectively reviewed the charts of 62 patients (62 eyes) (age, 72 +/- 15 years) with failed filtration surgery who underwent needle revision using MMC. A mixture of 0.01 ml of MMC (0.4 mg/ml) and 0.02 ml of bupivacaine with epinephrine was injected subconjunctivally. Twenty to 30 minutes later, a 30-gauge needle was used to perforate the area of subconjunctival fibrosis and re-establish flow., Results: Overall, 118 needing procedures (mean, 1.9 +/- 1.4 revisions per eye; range, 1-7) were performed on 62 eyes (mean follow-up, 9.9 +/- 3.7 months; range, 4.5-20.1 months). Thirty-six patients (58.1%) were needled once and 26 patients (41.9%) underwent more than 1 needling procedure. Intraocular pressure decreased from 24.1 +/- 6.4 mmHg (range, 18-44) before surgery to 11.5 +/- 4.8 mmHg (range, 1-26) at last follow-up (P = 5.51 x 10(-21)). Antiglaucoma medications decreased from 1.6 +/- 1.0 to 0.3 +/- 0.6 (P = 3.8 x 10(-14)). Successful single-needling procedure was highly correlated with race (white) and past conventional glaucoma filtration surgery of more than 4 years. Complications included serous choroidal detachment (10 eyes), suprachoroidal hemorrhage (1 eye), bleb leak (5 eyes), iris blocking sclerostomy (2 eyes), hyphema (2 eyes), corneal abrasion (2 eyes), and hypotony (1 eye)., Conclusion: Mitomycin needle revision appears to be an extremely effective way to revive failed filtration surgery. The incidence of complications compares favorably to trabeculectomy with MMC.

Purpose: Cataract and glaucoma commonly coexist in elderly patients and present complex treatment options. This study investigates the results of simultaneous treatment of both conditions using phacoemulsification with posterior chamber lens implant and mitomycin-augmented trabeculectomy (combined surgery)., Methods: A retrospective analysis was performed of 56 consecutive patients who had undergone combined surgery. Fifty-one (91%) of 56 patients had fornix-based conjunctival flaps resutured at the limbus. A variety of postoperative interventional techniques (mechanical and pharmacologic) were used to encourage the achievement of successful filtering blebs., Results: All patients had follow-up of at least 12 months. The mean preoperative intraocular pressure (IOP) was 20.2 mmHg (range, 14-43 mmHg) and the mean postoperative IOP was 10.7 mmHg (range, 4-17 mmHg). Fifty-three (95%) of 56 patients had IOPs of 15 mmHg or less at the completion of follow-up. All except two patients (96%) were able to discontinue all glaucoma medications. The filtering blebs that resulted from the fornix-based conjunctival flap procedures were predominantly large, diffuse, and noncystic. Best-corrected visual acuity was 20/40 or better in 47 (84%) of 56 of patients., Conclusion: Control of IOP and improvement of visual acuity can be achieved in a high percentage of patients with coexisting cataract and glaucoma by performing combined surgery using intraoperative mitomycin and fornix-based conjunctival flaps resutured to the limbus. The filtering blebs illustrated a distinctive morphology compared with blebs resulting from limbus-based conjunctival flap procedures.

The following article discusses the outcome of 60 eyes with various forms of glaucoma undergoing resident-performed argon laser trabeculoplasty (ALT). The majority (46/60) of eyes had primary open-angle glaucoma. Decrease in intraocular pressure (IOP) was not as great as reported in the literature. Our results suggest that initially treating 180 degrees of the angle is associated with improved overall results. ALT has proved to be a safe and effective alternative to conventional surgery for glaucoma in a residency training setting.

Krypton red (647.1 nm) or krypton yellow (568.2 nm) laser trabeculoplasty was performed in 15 phakic eyes of 14 patients. After an average follow-up of five months, these patients had an average drop of intraocular pressure of 8.9 mm Hg. In addition, in eight of these patients studied, argon laser trabeculoplasty was performed in the opposite eye. After an average follow-up of more than five months in these eight patients, the average drop of IOP was 7.2 mm Hg in the eyes with krypton laser trabeculoplasty and 6.8 mm Hg in the eyes with argon laser trabeculoplasty. This preliminary study indicates that laser trabeculoplasty may be effectively performed with krypton wavelengths.

Eighty-six eyes of 46 patients were studied retrospectively to determine the incidence of posterior synechiae after laser iridectomy. All eyes were dilated and studied with a slit lamp. The incidence of permanent posterior synechiae in the eyes in this study (37%) is much higher than that previously reported. There was a strong positive correlation between the use of miotic agents postoperatively and the finding of posterior synechiae. The probable pathogenesis of this complication is discussed, and methods to decrease the incidence of this complication are given.

Fore and hind milks from a single morning feed collected from 24 nursing mothers over 3 consecutive d were evaluated for sweetness, viscosity, and mouthcoat by a trained adult panel using magnitude estimation. Milks were perceived as sweet, thin, and low in mouthcoat. Hind milks were slightly more viscous and mouthcoating than fore milks. The higher fat content in hind milk was associated with higher estimation of physical viscosity. Milk fat content decreased as maternal age increased. Significant differences occurred between milks in lactose, fat, and protein contents. By use of a sweetness power function curve, the sweetness intensity of human milk was estimated as equivalent to a 2.12% sucrose solution.

Two patients with talc emboli of the retinal vasculature, both of them intravenous drug abusers, are described. One underwent a pars plana vitrectomy for removal of the vascularized vitreous mass that obscured the retina. The vitreous mass was presumably a result of retinal neovascularization secondary to the talc embolic. Other ocular findings that may be observed in the intravenous drug abuser are described.

Three related myopic individuals with primary angle closure glaucoma are reported. They had true myopia and not pseudomyopia secondary to increased lenticular index of refraction. We believe one of these individuals (-8.62 spherical equivalent) to have the most myopic case of primary angle closure glaucoma reported in the literature. Although myopia is associated with anatomical factors that offer considerable protection from primary angle closure glaucoma, its presence does not eliminate the possibility of this disease. Laser iridectomy was effective in the treatment of these patients.

We tested 145 samples of 20 different topical medications for the treatment of glaucoma to determine the average drop size of each preparation. The average drop volumes of different preparations varied between a minimum of 25.1 microliter and a maximum of 56.4 microliter, with an average drop volume of 39.0 microliter. Our findings contradict the common assumption that commercial eyedrops contain a volume of 50 to 75 microliters.