Penetration of ofloxacin and ciprofloxacin into the aqueous humor of eyes with functioning filtering blebs: a randomized trial.

OBJECTIVE: To determine concentrations of ofloxacin and ciprofloxacin hydrochloride in aqueous humor after topical or combined topical and oral administration in eyes with filtering blebs. DESIGN: A prospective, investigator-masked, randomized, controlled comparative study involving 36 eyes of 34 patients with functioning filtering blebs who were to undergo cataract surgery. Treatment groups received either topical ofloxacin or topical ciprofloxacin (instillation of 0.3% ophthalmic solution every 30 minutes for 4 hours before surgery), or a combined topical plus oral regimen (ciprofloxacin hydrochloride, four 100-mg tablets, or ofloxacin, one 400-mg tablet, administered 24-26, 12-14, and 2 hours preceding surgery). The main outcome measure was antibiotic concentration measured by chromatographic separation and mass spectrometry of aqueous samples obtained during surgery. RESULTS: Topical antibiotic treatment yielded mean concentrations of ofloxacin, 0.75 microg/mL, and ciprofloxacin, 0.21 microg/mL, in aqueous. With combined topical and oral therapy, significantly more ofloxacin was measured than ciprofloxacin (3.84 microg/mL vs 0.35 microg/mL [P<.001]). The combination regimen produced significantly greater ofloxacin levels than did topical therapy alone (P =.007). CONCLUSIONS: Ofloxacin penetrates better than ciprofloxacin into the aqueous of eyes with filtering blebs, particularly after combined topical and oral administration, by which ofloxacin reaches more than a 10-fold greater concentration than does ciprofloxacin. Combined topical and oral therapy with ofloxacin may be beneficial in the treatment of bleb-associated infections.

Cataract surgery after tube shunts.

PURPOSE: To determine the effect of cataract surgery on glaucomatous eyes with functioning tube shunts. METHODS: Retrospective analysis of 11 eyes of 11 patients with functioning tube shunts who underwent cataract extraction. RESULTS: The mean follow-up after cataract extraction was 21 +/- 27 months (range, 4-97 months). There was no statistically significant difference between the mean preoperative intraocular pressure and mean postoperative intraocular pressure (17.4 +/- 3.7 mm Hg vs 17.8 +/- 5.9 mmHg; P = 0.85, paired t test). Most patients exhibited a statistically significant rise or drop in pressure, but in none was there a clinically significant change. The mean number of preoperative and postoperative antiglaucoma medications was also not significantly different (1.5 +/- 1.1 vs 1.7 +/- 1.2; P = 0.44, paired t test). Snellen visual acuity improved at least 2 lines in 6 eyes (55%). Complications after cataract extraction included corneal edema in three eyes, one of which had subsequent loss of control of intraocular pressure. CONCLUSIONS: Eyes with a functioning tube shunt undergoing cataract extraction can maintain control of intraocular pressure while achieving visual improvement.

Outcomes of sequential tube shunts in complicated glaucoma.

OBJECTIVE: To evaluate intraocular pressure (IOP) control, change in visual acuity, and complications in eyes that have undergone a second glaucoma tube shunt procedure. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-two eyes of 22 patients that have undergone sequential tube implants for management of glaucoma. METHODS: Parameters analyzed included IOP, visual acuity, and number of hypotensive agent before each shunt procedure and at last follow-up visit. The overall IOP lowering effect attributable to each tube shunt was calculated. Any ocular complications after the second tube shunt were recorded. Success was defined as an IOP between 6 and 21 mm Hg and a 20% reduction in IOP from the second tube shunt procedure. Qualified successes met one of these two requirements at the last follow-up visit. Total failures did not meet any of the above criteria, required additional surgical intervention to lower IOP, or both. MAIN OUTCOME MEASURES: Intraocular pressure control, visual acuity preservation, and complications. RESULTS: At the last follow-up visit, the average percent reduction in IOP from both tube shunt procedures was 42+/-21%. The average percent IOP reduction from the second tube shunt was 33+/-17%. Eleven (50%) patients met the criteria for success, 8 (36.4%) patients were qualified successes, and 3 (13.6%) were failures. The median number of hypotensive agents decreased from two to one. Ten patients experienced new or worse pseudophakic bullous keratopathy after the second tube shunt, six of whom underwent penetrating keratoplasty. Thirteen (59%) patients maintained visual acuity within one line of their second tube shunt pre-operative Snellen visual acuity. Seven (32%) patients lost more than 2 lines, and one patient lost light perception. CONCLUSIONS: Although corneal morbidity is a common complication, a second tube shunt does not cause higher-than-expected rates of other complications associated with tube shunt surgery. Eyes that undergo a second tube shunt procedure can achieve pressure control, require fewer hypotensive agents, and may maintain stable visual acuity.

Sphingolipid-gated Ca2+ release from intracellular stores of endothelial cells is mediated by a novel Ca(2+)-permeable channel.

Sphingolipid-gated Ca2+ signaling is mediated through Ca(2+)-permeable channels. In this report, we characterize the properties of the channel in a human endothelial cell line (EA.hy926). Ca2+ release from intracellular stores is not antagonized by nifedipine, omega conotoxin G-VIa, or heparin. To further characterize the molecular properties of the channel, we developed a novel assay to directly measure efflux of Ca2+ from intracellular stores of permeabilized Xenopus oocytes. Following size fractionation by sucrose gradient, poly(A)+ RNA from EA.hy926 cells is microinjected into oocytes of Xenopus laevis. We find that the mRNA encoding Ca2+ release activity is approximately 1.5-2.0 kilobases in length. The sphingolipid-gated Ca(2+)-permeable channel is thus likely to be a novel Ca(2+)-permeable channel distinct from other characterized intracellular Ca2+ channels such as the ryanodyne receptor and the inositol 1,4,5-trisphosphate receptor. The method described here provides a new approach to further characterizing this channel and other intracellular Ca2+ channels.