PubMed Health⌕ Search

Biomedical subjects

L J Maguire

Publications and source records attributed to L J Maguire.

At least 19 recordsLinked to original sources
PubMed2001

Comparison of Chen Medium and Optisol-GS for human corneal preservation at 4 degrees C: results of transplantation.

PURPOSE: To compare results after transplantation of donor corneas stored in Chen Medium (containing beta-hydroxybutyrate without sodium bicarbonate or chondroitin sulfate) to corneas stored in Optisol-GS medium (containing sodium bicarbonate and 2.5% chondroitin sulfate). METHODS: We performed 32 consecutive penetrating keratoplasties with donor corneas stored at 4 degrees C in either Chen Medium or Optisol-GS by random assignment. Corneal thickness measurements were made at 1 day, 1 week, 3 weeks, 2 months, and 1 year postkeratoplasty. Specular microscopic images of the donor endothelium were obtained at the beginning of storage and 2 months and 1 year postkeratoplasty. The percentage of intact epithelium 1 day after keratoplasty and the graft epithelialization time were estimated by the surgeons. Donor rim cultures were performed. RESULTS: No statistically significant differences in corneal thickness or endothelial cell loss between the corneas stored in the two media were found at any time, although differences of less than 12% cell loss or 0.09-mm thickness at 2 months or less than 25% cell loss or 0.10-mm thickness at 1 year could not be excluded with 90% certainty in this small series. The mean percentages of intact graft epithelium on day 1, 64% for Chen Medium and 65% for Optisol-GS, were not significantly different. Endothelial cell density 2 months postkeratoplasty was significantly decreased for corneas stored in both media. Endothelial cell loss at 2 months was directly correlated with storage time in both media. CONCLUSIONS: After keratoplasty, no statistically significant differences in corneal thickness, epithelial survival, and endothelial cell loss were found between corneas stored in Chen Medium and Optisol-GS. Endothelial cell loss at 2 months was significantly correlated with storage time in both media.

Adult↗
PubMed1999

Irreversible corneal decompensation in patients treated with topical dorzolamide.

PURPOSE: To describe irreversible corneal decompensation after topical dorzolamide hydrochloride (Trusopt; Merck and Co, Inc, West Point, Pennsylvania) therapy in nine patients who had histories consistent with corneal endothelial compromise. METHOD: Multicenter review of patients' charts. RESULTS: Nine eyes of nine patients developed overt corneal decompensation after starting topical dorzolamide, a condition that did not resolve with drug cessation. This occurred after 3 to 20 weeks (mean, 7.8) of therapy. All nine patients had undergone intraocular surgery. Eight patients had undergone cataract surgery; three were aphakic and three had posterior chamber intraocular lenses. Two patients had anterior chamber intraocular lenses and also had undergone trabeculectomies. Four patients had undergone penetrating keratoplasties, each case complicated by episodes of corneal allograft rejection that were successfully treated. Two patients had asymptomatic Fuchs endothelial dystrophy. Seven patients have since undergone successful penetrating keratoplasties. CONCLUSION: The reports suggest that dorzolamide can cause irreversible corneal edema in a subset of glaucoma patients with endothelial compromise. The findings suggest a rationale for research into the long-term effects of dorzolamide on the corneal endothelium.

Administration, Topical↗
PubMed1999

Keratocyte density in vivo after photorefractive keratectomy in humans.

PURPOSE: To determine changes in keratocyte density in central human corneas in vivo after photorefractive keratectomy (PRK). METHODS: Fifteen patients (25 eyes) received excimer PRK (VISX Star) with epithelial removal by laser-scrape (43 microns ablation followed by manual scrape) to correct myopia between -1.5 D and -7.25 D. Corneas were examined by using confocal microscopy in vivo before PRK and at 1 day, 5 days, 1 month, and 3 months after PRK. A custom automated image-processing algorithm identified bright objects (keratocytes) against a dark background and estimated keratocyte density by using the number and size of the objects. Cell density was quantified in anteroposterior stromal regions after PRK and compared to cell density in corresponding pre-PRK regions. RESULTS: One day after PRK, keratocyte density increased 9% in the anterior third of the stroma (pi = .003), was unchanged in the middle third of the stroma (pi = .481), and decreased 6% in the posterior third of the stroma (pi = .038). Keratocyte density remained elevated in the anterior stroma to 3 months after PRK; at this time, there was a 13% increase in keratocyte density throughout the full-thickness stroma (pi < .001). CONCLUSIONS: Keratocyte density was increased in the anterior stroma immediately after PRK in humans. Three months later, keratocyte density was increased in all anteroposterior stromal regions, suggesting that PRK affects keratocytes throughout the entire central cornea.

Adult↗
PubMed1997

The value of routine donor corneal rim cultures in penetrating keratoplasty.

OBJECTIVE: To investigate the value of donor corneal rim cultures performed routinely at the time of penetrating keratoplasty. DESIGN: Retrospective review of Mayo Clinic medical records for all corneal transplantations for which donor rim cultures have been performed. MAIN OUTCOME MEASURES: Frequency of positive cultures, occurrence of endophthalmitis within 2 months of undergoing surgery, action taken in response to the culture results, and costs of cultures. RESULTS: Donor rim culture results were available for 1078 of 1083 consecutive transplantations performed from 1981 to 1995. Three cases of endophthalmitis (0.28%) and 1 suture abscess occurred. Rim cultures were negative in all of these cases. Action was documented in response to positive cultures in 17 cases (8.1%). The estimated average cost of routine rim cultures in 1994 was $137 per donor cornea. Bacterial or fungal cultures were positive in 209 (19.4%) cases. Two microorganisms were cultured simultaneously in 17 cases (1.6%) and 3 in 2 cases (0.2%). Staphylococcus coagulase-negative (130 cases [12.1%]), and Streptococcus species, viridans group (23 cases [2.1%]), were the most common isolates. Fifty-two (62.7%) of 83 coagulase-negative Staphylococcus species isolates tested were resistant to gentamicin. There were more positive cultures from corneas stored in Optisol (37/183 [20%]) than in Optisol GS (16/144 [11%]) (P = .03). Fewer cultures were positive from live donors (9/93 [10%]) compared with cadaveric donors (181/ 909 [20%]) (P = .02). Positive cultures were more frequent for corneas excised in situ (39/125 [31.2%]) than for those enucleated (152/851 [17.9%]) (P < .001). CONCLUSIONS: Despite differences in rates of positive donor rim cultures with different harvesting and storage techniques, for our practice, routine donor corneal rim cultures had no predictive value for infective complications of penetrating keratoplasty and, therefore, added an unnecessary expense to the management of our patients.

Bacterial Infections↗
PubMed1997

Keratometric results of penetrating keratoplasty with the Hessburg-Barron and Hanna trephine systems using a standard double-running suture technique.

PURPOSE: To compare final, sutures-out, keratometric results of penetrating keratoplasty using two different suction trephine systems and a standard double-running suture technique. METHODS: Keratometric data after final suture removal were compared retrospectively for three groups of transplants: Group 1, 7.50-mm Hessburg-Barron recipient trephine and 7.70-mm modified Lieberman donor punch (n = 70); Group 2, 7.50-mm Hessburg-Barron recipient trephine and 8.00-mm modified Lieberman donor punch (n = 18); Group 3, 7.50-mm Hanna recipient trephine and 7.75-mm Hanna donor punch (n = 68). RESULTS: Final average keratometry was 46.7 +/- 2.4 D (mean +/- SD, diopters), and final median keratometric astigmatism was 4.6 D (2.6-7.4 D, interquartile range), with no significant difference between groups. Final average keratometry values increased from preoperative values by 3.3 +/- 2.7 D. The correlation between preoperative average keratometry values and final values was low (rs = 0.2; p = 0.07). Average keratometry values increased by 2.3 D (median) after 10/ 0 suture removal (p < 0.0001) and by 0.2 D (median) after 11/0 suture removal (p = 0.09), with no significant difference between groups. There was a negative correlation between donor age and overall change in average keratometry (rs = -0.3; p = 0.002). Visual acuity improved by a median of 5 lines, with no significant difference between trephine systems. CONCLUSIONS: There was no statistically significant difference in keratometric results using these two suction trephines with a standard suture technique. Final graft curvature was greater with both suction trephines compared with previously published results of transplants using hand-held trephines with the same suture technique.

Aged↗
PubMed1996

Specular microscopy before and after enucleation of live donor eyes.

PURPOSE: To compare the results of specular microscopic examination of corneal endothelium before and after enucleation of eyes from live donors. METHODS: Endothelial cell density (ECD), coefficient of variation of cell area (CV), and percent hexagonal cells were compared for 34 cornea donors before enucleation of their eyes and after excision of the corneoscleral rims and placement in preservative media. RESULTS: There was no statistically significant difference in ECD, CV, or percent six-sided cells after enucleation. The pre-enucleation and post-enucleation ECD measurements were significantly correlated (rs = .85, P < .0001). Mean percentage change in ECD was -0.7% +/- 6.0%. CONCLUSIONS: There was no significant difference in ECD, CV, or percent six-sided cells between measurements taken from the epithelial side in vivo and those taken of the same corneas from the endothelial side in vitro after enucleation and corneoscleral rim excision. These findings suggest that it is reasonable to compare postkeratoplasty clinical measurements with those of the donor corneas taken in the eye bank.

Cell Count↗
PubMed1995

Biomicroscopic evidence of keratoconus with an apex power of 45.5 diopters by videokeratoscopy.

PURPOSE/METHODS: We studied a mild case of keratoconus, which had biomicroscopic evidence of keratoconus. With videokeratoscopy, we examined a 55-year-old man with a family history of keratoconus who showed biomicroscopic evidence of bilateral keratoconus. RESULTS/CONCLUSIONS: Videokeratoscopy of the least affected eye showed a map pattern consistent with an inferiorly displaced cone, but surprisingly the apex power measured only 45.5 diopters. Patients with apex power as low as 45.5 diopters can show biomicroscopic evidence of keratoconus. If a central database existed for such unusual cases, eye-care specialists could contribute to it and provide valuable material to researchers trying to improve automated methods to differentiate between normal and keratoconic corneas.

Cornea↗
PubMed1994

Ophthalmic findings in scleromyxedema.

PURPOSE: To catalog ophthalmic findings in a cohort of patients with scleromyxedema. METHODS: Thirty-five biopsy-proven patients with scleromyxedema evaluated at the Mayo Clinic in Rochester, Minnesota, from 1960 to 1991 were identified. Eye examinations were performed on 17 of the patients. Ophthalmic findings not attributable to other systemic or ocular disease were recorded. RESULTS: The following abnormalities were considered secondary to scleromyxedema: corneal opacities (2 patients), thickened eyebrow or eyelid skin (4 patients), lagophthalmos (1 patient), and ectropion (2 patients). One patient who had concurrent polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome also had choroidal folds and papilledema. A corneal biopsy in one patient disclosed deposits of acid mucopolysaccharide, consistent with one of two previously published cases. CONCLUSION: A series of patients with scleromyxedema was reviewed. This systemic disorder infrequently may cause visually significant ophthalmic manifestations, including eyelid changes and corneal deposits. Further study is needed to characterize better the nature of the corneal opacities.

Adult↗
PubMed1994

Coccidioidomycosis with necrotizing granulomatous conjunctivitis.

A patient with a steroid-resistant conjunctival nodule developed severe necrotizing granulomatous conjunctivitis during aggressive treatment with topical, subconjunctival, and systemic steroids. Culture of the tissue yielded Coccidioides immitis. A cavitary lesion was noted on a chest radiograph, and the same organism was recovered from a lung biopsy specimen. The granulomatous conjunctivitis was controlled only after aggressive debridement of the affected area and months of treatment with topical amphotericin B and oral fluconazole. A review of the literature suggests that subclinical ocular involvement from pulmonary coccidioidomycosis may be more common than generally believed. Conditions that blunt the host immune response may lead to a higher incidence of clinically significant ocular involvement.

Aged↗
PubMed1993

Evaluating the reproducibility of topography systems on spherical surfaces.

Newly devised software was used to compare the ability of the Topographic Modeling System-1 (Computed Anatomy, New York, NY) and the Corneal Analysis System (EyeSys Laboratories, Houston, Tex) to reproduce power measurements on spherical surfaces. Reproducibility results were compared for spheres of 40.00, 42.50, and 44.00 diopters. The program determines the absolute difference in corneal power at defined keratoscope positions for paired examinations of the same eye. Four examinations of each sphere were obtained with each instrument. Individual points were sampled at specific keratoscope locations at 30 degrees-semimeridional intervals. The program compared variability of measurements at four defined ranges of distance from the vertex normal: within 0.60 mm, 0.61 to 1.5 mm, 1.51 to 2.5 mm, and 2.5 mm or greater. The Corneal Analysis System showed significantly greater variability of readings obtained within 0.60 mm of the vertex normal for all three spheres (P = .001 by Duncan's multiple comparison procedure), whereas the Topographic Modeling System-1 showed equally consistent readings within 0.60 mm as it did between 0.61 and 1.5 mm from the vertex normal.

Computer Simulation↗
PubMed1992

Corneal complications after cataract surgery in patients with rheumatoid arthritis.

Peripheral ulcerative keratopathy and necrotizing scleritis have been reported in rheumatoid arthritis patients after cataract surgery, but the incidence of these complications during the immediate postoperative period is unknown. We retrospectively studied 70 patients with rheumatoid arthritis who underwent a total of 86 cataract extractions between 1973 and 1988. Only 15 of the patients had a preoperative history of keratoconjunctivitis sicca. The best corrected postoperative visual acuity was greater than or equal to 20/30 in 81% of eyes. No episodes of scleritis or peripheral ulcerative keratopathy occurred during the 8-week postoperative period. Three patients (all from the sicca group) developed diffuse superficial punctate keratopathy and/or filamentary keratitis. Results suggest that serious corneal complications after cataract surgery are uncommon in rheumatoid arthritis patients similar to the population found in our study (95% Poisson confidence interval 0-6.6%).

Aged↗
PubMed1991

Developing entry criteria for studies of severe postkeratoplasty astigmatism.

Investigators who use keratometry or topography systems to plan operations for the correction of severe postkeratoplasty astigmatism assume the study group is homogeneous. To test this hypothesis, we established four entry criteria we believed were necessary to ensure a homogeneous group. The criteria were as follows: (1) best-corrected or pinhole visual acuity greater than or equal to 20/40; (2) graft well centered relative to the corneal light reflex; (3) corneal light reflex within 0.5 mm of the center of the entrance pupil; and (4) a minimum of ten central keratoscope rings of the Corneal Modeling System accurately digitized. A retrospective analysis of the keratoscope images of 20 consecutive patients (20 eyes) referred for correction of postkeratoplasty astigmatism was performed to determine the percentage of patients who met the proposed criteria. Only seven (35%) simultaneously met all four entry criteria. Investigators interested in comparing techniques to correct this problem are faced with a dilemma. Strict entry criteria will ensure a homogeneous study group but will exclude most patients. More lenient entry criteria will increase the number of eligible subjects but will introduce heterogeneity, which may confound results.

Astigmatism↗
PubMed1991

Congenital entropion with intact lower eyelid retractor insertion.

Congenital lower eyelid entropion is generally considered to result from improper development of the retractor aponeurosis insertion to the inferior portion of the tarsal plate. We treated three patients with this uncommon disorder. At operation, aponeurotic defects were anticipated and specifically sought, but in each case the lower eyelid retractors were inserted normally. In two patients, entropion was relieved by surgical disinsertion and then advancement of the retractors. In the third patient, who also had multiple concomitant facial and systemic developmental anomalies, improvement in the lower eyelid malpositions required a combination of procedures. The intraoperative findings in our patients demonstrate that disinsertion of the lower eyelid retractors is not a universal etiologic mechanism in congenital entropion.

Entropion↗
PubMed1991

Identifying progression of subclinical keratoconus by serial topography analysis.

We performed serial slit-lamp examinations and topography analysis on a patient whose initial topographic map suggested a diagnosis of keratoconus to us but which others interpreted as normal topography. Topography analysis documented cone progression during a two-year period. The initial map showed a cone apex power of 44.5 diopters located 2.1 mm inferior to the vertex normal. An oblong-shaped area of maximum power was surrounded by concentric bands of lower power. Corneal surface power ranged from 41.5 to 44.5 diopters. Two years later cone apex power increased to 51.0 diopters, and the patient developed a Fleischer's ring, Vogt's striae, and mild visual aberration. Our findings suggest the use of topography analysis systems in documenting subclinical cone progression. Topography systems may be a useful tool in the study of the true incidence and natural progression of subclinical keratoconus.

Cornea↗