Biomedical subjects

R P Lehmann

Publications and source records attributed to R P Lehmann.

At least 19 recordsLinked to original sources

PubMed1996

Cytomegalovirus keratitis in acquired immunodeficiency syndrome.

A man with acquired immunodeficiency syndrome developed a generalized rash and bilateral dendritic epithelial keratitis without retinitis. Cytologic examination of superficial corneal scrapings showed many megalosyncytial giant cells that were highly characteristic of cytomegalovirus (CMV) infection. Viral cultures yielded CMV from 2 separate specimens obtained by corneal epithelial debridement from both eyes. The slightly elevated, opaque, branching, nonulcerative epitheliopathy recurred after corneal scrapings and persisted despite oral and topical antiviral therapy. Stromal keratouveitis subsequently developed. This case report confirms that CMV can produce corneal involvement and suggests that CMV keratitis may be an emergent complication of acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗

PubMed1995

The efficacy of apraclonidine as an adjunct to timolol therapy. Apraclonidine Adjunctive Therapy Study Group.

OBJECTIVE: To compare the intraocular pressure (IOP) lowering efficacy of 0.5% and 1.0% apraclonidine hydrochloride when used adjunctively with 0.5% timolol maleate in 129 patients. DESIGN: A multicenter, randomized, double-masked clinical trial. Adult patients of either sex diagnosed as having either open-angle glaucoma or ocular hypertension were enrolled in the study. Patients using only 0.5% timolol maleate twice daily for at least 4 weeks and who had 8 AM IOPs of at least 22 mm Hg and no greater than 30 mm Hg 12 hours after dosing were eligible for the study. After 8 AM baseline IOPs were obtained while patients were taking timolol only, they were then randomized to receive either 0.5% or 1.0% apraclonidine twice daily in addition to their timolol. Intraocular pressures were measured at 8 AM (before morning dosing) and at 11 AM (3 hours after dosing) on days 14 and 90 and at 8 AM only on day 45. RESULTS: Both concentrations of apraclonidine produced significant IOP reductions from baseline at all visits (P < .001). At 8 AM, after the nighttime dose, the additional mean IOP reduction from the timolol baseline ranged from 2.5 to 3.3 mm Hg (10.3% to 13.6% reduction, respectively). At 11 AM, 3 hours after the morning dose, the additional IOP reduction from the timolol baseline ranged from 4.7 to 5.2 mm Hg (20.0% to 21.7%, respectively). No difference in IOP reduction was observed between the 0.5% and 1.0% apraclonidine concentrations and no loss of IOP efficacy was observed for either concentration for the duration of the study. Sensitivity to 0.5% and 1.0% apraclonidine was observed in nine (13.8%) and 13 (20.3%) patients, respectively. Overall, therapy was discontinued owing to ocular or nonocular side effects with 0.5% and 1.0% apraclonidine in 14 (21.5%) and 16 (25%) patients, respectively. CONCLUSIONS: We believe that 0.5% apraclonidine is equally effective as 1.0% apraclonidine when used twice daily as the first adjunctive drug to timolol. The drug effect is maintained for at least 90 days.

Adrenergic alpha-Agonists↗

PubMed1995

Short-term efficacy of apraclonidine hydrochloride added to maximum-tolerated medical therapy for glaucoma. Apraclonidine Maximum-Tolerated Medical Therapy Study Group.

PURPOSE: We determined whether the addition of topical apraclonidine hydrochloride to eyes that are receiving maximal medical therapy but still have inadequate intraocular pressure control and that are scheduled to undergo surgery could adequately decrease intraocular pressure, postponing the need for further intervention. METHODS: We performed a prospective, 90-day, multicentered, placebo-controlled, double-masked parallel study. We enrolled one eye each of 174 glaucoma patients with inadequate intraocular pressure control who were on maximally tolerated medical therapy. We continued to administer maximum medical therapy for glaucoma. Study medications were either apraclonidine hydrochloride 0.5% or placebo (apraclonidine's vehicle). Patients were instructed to take the study medication every eight hours. We measured intraocular pressure, change in intraocular pressure from baseline, and the number of eyes requiring surgery after the addition of study medication. RESULTS: Fifty-two (60%) of 86 patients treated with apraclonidine maintained adequate intraocular pressure control throughout the study and avoided surgery, compared with 28 (32%) of 88 patients treated with placebo (P < .001). Apraclonidine treatment resulted in significantly more patients attaining an additional 20% reduction or more in intraocular pressure from baseline and an intraocular pressure less than or equal to 20 mm Hg (P < .05). The most common ocular complication was conjunctival hyperemia (11 of 86 patients, 12.8%). The most frequent nonocular problem was dry mouth (four patients, 4.7%). CONCLUSION: Apraclonidine appeared to be safe in all eyes and efficacious in some eyes. It significantly lowered intraocular pressure when used in combination with maximally tolerated medical therapy, which delayed or prevented further glaucoma surgery for at least 90 days in 52 (60%) of 86 treated patients.

Adrenergic alpha-Agonists↗

PubMed1995

Topical apraclonidine hydrochloride in eyes with poorly controlled glaucoma. The Apraclonidine Maximum Tolerated Medical Therapy Study Group.

OBJECT: We determined whether the addition of topical apraclonidine hydrochloride to eyes receiving maximal medical therapy, with inadequate intraocular pressure (IOP) control, and scheduled to undergo surgery, could adequately lower IOP, postponing the need for surgical intervention. DESIGN: A prospective 90 day, multi-centered, placebo-controlled, doublemasked parallel study. PATIENTS: We enrolled 174 glaucoma patients with inadequate IOP control on maximally tolerated medical therapy. All were candidates for either laser trabeculoplasty or invasive surgical intervention. We enrolled only one eye per patient. INTERVENTIONS: We continued to administer maximum-tolerated medical therapy for glaucoma. Patients took the study medication every eight hours. Study medications were either apraclonidine hydrochloride 0.5% or placebo (apraclonidine's vehicle). MAJOR OUTCOME MEASURES: We evaluated IOP, IOP change from baseline, and the number of eyes requiring surgery after the addition of study medication. RESULTS: Sixty one percent of patients treated with apraclonidine maintained adequate IOP control throughout the study, avoiding additional surgery compared to 33.9% patients treated with placebo (P < .001). Apraclonidine treatment resulted in significantly more patients achieving either an additional > or = 20% reduction in IOP from baseline (resulting in an IOP < or = 20 mm Hg) (P < 0.05). The most common ocular complications were conjunctival hyperemia (12.6%), itching and foreign body sensation (6.8%), and tearing (4.5%). The most frequent non-ocular adverse events related to apraclonidine were dry mouth (4.5%) and unusual taste perception (2.2%). CONCLUSIONS: Apraclonidine appears safe and efficacious. It significantly lowered IOP when used in combination with a patient's maximum tolerated medical therapy. This delayed or prevented further glaucoma surgery for at least 90 days in approximately 60% of treated patients.

Administration, Topical↗

PubMed1994

Structural differences in chlorosomes from Chloroflexus aurantiacus grown under different conditions support the BChl c-binding function of the 5.7 kDa polypeptide.

Structurally different chlorosomes were isolated from the green photosynthetic bacterium Chloroflexus aurantiacus grown under different conditions. They were analysed with respect to variable pigment-protein stoichiometries in view of the presumed BChl c-binding function of the 5.7 kDa chlorosome polypeptide. Under high-light conditions on substrate-limited growth medium the pigment-protein ratio of isolated chlorosomes was several times lower than under low-light conditions on complex medium. Proteolytic degradation of the 5.7 kDa polypeptide in high-light chlorosomes led to a 60% decrease of the absorbance at 740 nm. The CD spectrum of high-light chlorosomes exhibited a sixfold lower relative intensity at 740 nm (delta A/A740) than low-light chlorosomes, but it showed a fivefold increase in intensity upon degradation of the 5.7 kDa polypeptide compared to a twofold increase in low-light chlorosomes. It seems probable that BChl c in the chlorosomes is present as oligomers bound to the 5.7 kDa polypeptide. Our data suggest further that compared to low-light chlorosomes smaller oligomers or single BChl c molecules are bound to the 5.7 kDa polypeptide in high-light chlorosomes resulting in lower rotational strength.

Amino Acid Sequence↗

PubMed1990

Paired comparison of contrast sensitivity in diffractive multifocal IOLs and conventional monofocal IOLs.

Multifocal intraocular lens (IOL) optics produce a retinal image of reduced contrast, which results from splitting incoming light between multiple focal points. This study sought to determine whether the reduced-contrast image results in functional loss of contrast sensitivity. Contrast sensitivity was measured in patients in the US Food and Drug Administration (FDA) study of the 3M Diffractive IOL, using the Pelli-Robson Letter Chart. Fifty-eight of these patients, including six from our clinic, were 'best-case' patients with no pathology, and also had paired multifocal/monofocal implants. Data from these 'best-care' patients with paired eyes indicate no functional difference in contrast sensitivity. Additional data obtained on our six patients with the Regan Low Contrast Charts suggest small predictable differences may exist for some patients at very low contrast levels. Further study is needed to determine whether these differences have functional significance.

Aged↗

PubMed1976

Cilioretinal arteries. A study based on review of stereo fundus photographs and fluorescein angiographic findings.

The incidence of cilioretinal arteries in 2,000 eyes of 1,000 consecutive patients was determined by review of stereo color fundus photographs and fluorescein angiographs. One or more cilioretinal arteries were present in 49.5% of all patients or in 32.1% of the eyes. The arteries occurred bilaterally in 14.6% and contributed to some portion of the macular circulation in 18.7% of the patients. A great deal of variability of size, number, and distribution of cilioretinal vessels was observed. Prior studies that were based on direct visualization of the fundus have reported cilioretinal arteries in 7% to 29.6% of patients examined. Careful review of stereo fundus photographs and early phase fluorescein angiographs aided in the observation of these vessels that might otherwise have been unrecognized. We believe the method of review accounts for the high incidence of cilioretinal arteries in our series.

Ciliary Body↗

PubMed1975