Biomedical subjects

D C Broadway

Publications and source records attributed to D C Broadway.

27 records · Page 2Linked to original sources

PubMed1997

A comparison of healthy, ocular hypertensive, and glaucomatous optic disc topographic parameters.

PURPOSE: To compare the optic discs of 62 healthy individuals 68 patients who have ocular hypertension (OH), and 182 patients with primary open-angle glaucoma (132 high-tension glaucoma (HTG) and 50 normal-tension glaucoma (NTG)), and determine whether disc size exerted an influence on the group differentiation. PATIENTS AND METHODS: Standard criteria were used to define glaucoma and normality. Ocular hypertension was defined as having raised intraocular pressure, a normal visual field, and a healthy optic disc/retinal nerve fiber layer (RNFL). The optic disc of one eye from each individual was analyzed using a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph software version 1.11, Heidelberg Engineering, Heidelberg, Germany). Thirteen topographical, volumetric, and shape parameters were compared between the three diagnostic groups. In addition, the individuals were divided into subgroups on the basis of disc size to determine any effect of disc size on the differentiating ability of the confocal scanning laser ophthalmoscope. Differences between the groups were evaluated using an analysis of variance. RESULTS: Glaucomatous optic discs were found to differ from both healthy and OH discs, although no differences in disc area between the groups were identified. On the basis of disc size, differentiating the glaucomatous discs was best for midsized discs of 2 mm2 to 3 mm2. However, no difference was found between healthy and OH discs, even when allowing for disc size. CONCLUSIONS: Ocular hypertensive optic discs (with a clinically normal appearance) could not be distinguished from healthy discs using a confocal scanning laser ophthalmoscopic technique. Glaucomatous optic discs were found to differ from both healthy and OH discs, with a limited effect of disc size.

Analysis of Variance↗

PubMed1996

Reversal of topical antiglaucoma medication effects on the conjunctiva.

OBJECTIVE: To determine whether the adverse effects of antiglaucoma medications could be reversed before filtration surgery, potentially reducing the risk of subsequent failure. METHODS: One month before surgery, 30 patients who were receiving multiple antiglaucoma medications underwent an inferior bulbar conjunctival biopsy, ceased using sympathomimetic drops, and began treatment with topical corticosteroid, (1% fluorometholone four times daily). At the time of surgery two conjunctival biopsy specimens were obtained, one from the operation site (superior bulbar region), and one from the inferior bulbar region. The biopsy specimens were quantitatively analyzed by light microscopy. In addition, the outcome of first trabeculectomy for 16 of these patients was compared with that of 16 matched patients who had not undergone an altered preoperative regimen of topical therapy. RESULTS: During a 1-month period a notable decrease occurred in the number of fibroblasts and inflammatory cells throughout the conjunctiva. Inferior bulbar conjunctiva was found to be representative of superior bulbar conjunctiva with respect to these changes. Furthermore, evidence comparing the matched patients suggested that the altered preoperative regimen may have improved the success rate of trabeculectomy. CONCLUSIONS: The preoperative regimen used reversed the adverse conjunctival effect of topical medication. The regimen may be of clinical benefit in improving the success rate of trabeculectomy.

Administration, Topical↗

PubMed1994

Adverse effects of topical antiglaucoma medication. I. The conjunctival cell profile.

OBJECTIVE: To determine the effect of various long-term topical antiglaucoma regimens on the cell population profile of the conjunctiva. METHODS: Conjunctival biopsy specimens from 124 patients undergoing filtration surgery were assessed quantitatively by light microscopy. Preoperatively, the patients had used a drug for only a brief period (group A; n = 28), a beta-blocker alone (group B; n = 31), a beta-blocker in combination with a miotic (group C; n = 33), or a combination of beta-blocker, miotic, and sympathomimetic (group D; n = 32). RESULTS: The conjunctiva in groups A and B was similar. Group C conjunctiva differed, but the changes were most marked in biopsy specimens from patients in group D, where there was a significant decrease in goblet cells (P < .05); increase in pale cells, macrophages, and lymphocytes within the epithelium (P < .001); and increase in fibroblasts (P < .001), macrophages (P < .001), mast cells (P < .05), and lymphocytes (P = .01) in the substantia propria. In addition, the effect of duration of therapy was assessed. Administration of topical medication for more than 3 years was found to increase the numbers of pale cells within the epithelium (P < .05); fibroblasts (P < .05), macrophages (P < .001), lymphocytes (P < .01), and mast cells (P = .001) within the superficial substantia propria; and the numbers of fibroblasts (P = .01) and macrophages (P < .05) within the deep substantia propria. CONCLUSIONS: The compared treatment regimens affected the conjunctiva to different degrees, with multiple-drug topical therapy exerting the greatest effect on the degree of subclinical inflammation within the conjunctiva. The results also indicated that administration of topical medication, irrespective of type, for 3 years or more induced a significant degree of subclinical inflammation.

Administration, Topical↗

PubMed1994

Adverse effects of topical antiglaucoma medication. II. The outcome of filtration surgery.

OBJECTIVE: To determine the effect of long-term topical antiglaucoma therapy on the results of glaucoma filtration surgery and to relate any differences to the cell population profile of the conjunctiva. METHODS: Filtration surgery was performed in 124 patients (trabeculectomy in 112 and triple procedures [trabeculectomy, cataract extraction, and intraocular lens implantation] in 12), and the outcome of these procedures was assessed after a minimum follow-up of 6 months. A conjunctival biopsy specimen was obtained at the time of surgery. The patients were divided into four groups according to the type of topical therapy administered. The duration of therapy tended to be greater for the patients treated with a greater number of medication types. The outcome of trabeculectomy was assessed in 106 of the patients. RESULTS: In comparison with the briefly treated-primary surgery group, the success rate of trabeculectomy (90% [n = 28]) was similar to that in the group treated with beta-blockers (93% [n = 29]). The trabeculectomy success rate for patients treated with beta-blockers and miotics was significantly lower (72%, P < .01 [n = 29]), and that for the group treated with beta-blockers, miotics, and sympathomimetics was even lower (45%, P < .001, [n = 20]). CONCLUSIONS: Various treatment regimens were associated with differential effects on the success rate of trabeculectomy. Long-term topical combination therapy was identified as a significant risk factor for failure of trabeculectomy. Preoperative conjunctival cell counts from patients whose trabeculectomies were successful were compared with those whose trabeculectomies failed. Failure was associated with significantly more pale cells (P < .01), macrophages (P < .05), and lymphocytes (P < .05) in the epithelium; fibroblasts (P < .05) and macrophages (P < .05) in the superficial substantia propria; and both macrophages and lymphocytes in the deep substantia propria (P < .01). Thus, preoperative subclinical conjunctival inflammation induced by previous topical medication was identified as a risk factor for failure of trabeculectomy.

Administration, Topical↗

PubMed1994

Mycobacterium chelonei keratitis: a case report and review of previously reported cases.

A 56-year-old woman who wore hard contact lenses developed a keratitis due to Mycobacterium chelonei. The organism was only sensitive to imipenem and partially to ciprofloxacin and erythromycin. After an initial response to topical therapy with these antibiotics the infection relapsed and a penetrating keratoplasty was performed, with resulting cure. M. chelonei has not previously been reported as a cause of keratitis associated with hard contact lens wear; neither has its treatment with imipenem and/or ciprofloxacin. A detailed photographic record showing the natural history of the keratitis is presented. Previously reported cases of M. chelonei keratitis are reviewed.

Ciprofloxacin↗

PubMed1993

Young patient trabeculectomy. Assessment of risk factors for failure.

BACKGROUND: Various risk factors for failure of glaucoma filtering surgery, including young age, have been suggested. METHODS: A retrospective study of 113 trabeculectomies in 113 patients, ranging in age between 11 and 49 years (mean, 33.3 +/- 10.5 years), was carried out to determine the influence of these risk factors in young patients. RESULTS: A successful outcome (intraocular pressure [IOP] < or = 21 mmHg without antiglaucoma treatment), assessed by life-table analysis, was achieved in 54% of trabeculectomies after 38 months (mean follow-up, 36.7 +/- 29.7 months). Previous ocular surgery (e.g., glaucoma filtering, cataract, or conjunctival surgery) and previous laser therapy (i.e., argon laser trabeculoplasty and YAG laser iridotomy) both significantly reduced the success rate. An IOP greater than 40 mmHg during the course of the disease was found to adversely affect the outcome. No direct correlation between success rate and age and no racial difference were demonstrated. Success rates for specific diagnoses were not significantly different. Postoperative subconjunctival injections of 5-fluorouracil (5-FU) did not significantly improve the success rate. A Cox regression analysis of various prognostic variables identified previous cataract surgery (hazard ratio, 4.4), argon laser trabeculoplasty (hazard ratio, 3.4), previous glaucoma filtering surgery (hazard ratio, 2.5), nonfiltering glaucoma surgery (hazard ratio, 2.2) and IOP greater than 40 mmHg (hazard ratio, 2.4) to be the major risk factors for glaucoma filtering surgery failure. CONCLUSION: A majority (74%) of the patients in our series had at least one of these risk factors, thus explaining why young patients, in general, have lower success rates for trabeculectomy.

Adolescent↗

PubMed1993

The importance of cellular changes in the conjunctiva of patients with uveitic glaucoma undergoing trabeculectomy.

The results of trabeculectomy in patients with glaucoma secondary to uveitis are poor, but the exact cause of this remains unknown. Therefore, a study was undertaken to determine differences between conjunctiva from patients with glaucoma secondary to uveitis and that from patients with primary open angle glaucoma. Conjunctival biopsies from three patient groups were quantitatively analysed by light microscopy. Group A consisted of 10 patients with glaucoma secondary to uveitis who, prior to surgery, had been treated with topical steroids and topical beta-blocker drugs. Control groups (groups B and C) each consisted of 10 patients with primary open angle glaucoma for whom primary trabeculectomy (group B) or trabeculectomy following failure of topical beta-blockers alone (group C) was planned. Treatment with topical beta-blocker drugs was found to redistribute mast cells within the conjunctiva but to have no significant effect on cell numbers. In comparison with either control group, uveitic conjunctiva was found to contain significantly more fibroblasts, lymphocytes and macrophages. It is possible that these differences are responsible for an enhanced risk of excessive external bleb fibrosis, failure of filtration surgery and poor results with adjunctive 5-fluorouracil.

Adrenergic beta-Antagonists↗

PubMed1993

Chronic progressive conjunctival cicatrisation.

The aim of this review is to demonstrate the spectrum of conditions encompassed by the term 'chronic progressive cicatrising conjunctivitis', to discuss mechanisms of conjunctival scar tissue formation and to describe the sequelae and therapeutic options in this potentially blinding condition. Chronic progressive cicatrising conjunctivitis is found in association with some mucocutaneous disorders (cicatricial pemphigoid, linear IgA disease), as part of paraneoplastic syndromes and after long-term treatment with certain systemic and topical medications (pseudo-pemphigoid). Recent studies on the conjunctiva of pemphigoid patients indicate that macrophages may play a pivotal role in chronic progressive conjunctival cicatrisation. They mediate the transition from inflammation to scar tissue by secretion of fibrogenic cytokines. There is evidence that similar mechanisms are involved in the other fibrosing conjunctival disorders. Sequelae of chronic conjunctival cicatrisation include the obstruction of lacrimal and meibomian glands, tear film alterations, trichiasis, keratopathy and blindness. Present possibilities and future options for the treatment of this condition are discussed.

Chronic Disease↗

PubMed1992

Intra- and inter-observer variation of optic nerve head measurements in glaucoma suspects using disc-data.

The aim of this study was to determine the intra- and inter-observer variation in the use of a system designed for exact measurements from standard optic nerve head photographs. The commercially available system consisted of a colour CCD Videocamera, a dedicated frame grabber and customized software run on a IBM AT compatible computer. Masked measurements were made 3 times by 2 observers, from stereophotographs of the optic nerve head of 56 eyes from 30 glaucoma suspects. The cup was defined on the basis of contour, not pallor and the disc area was defined as the area inside Elschnig's ring. Intra-observer variances were 0.001 +/- 0.001 mm2 for cup area (mean +/- SD), 0.002 +/- 0.002 mm2 for disc area and 0.002 +/- 0.003 mm2 for rim area. These values for intra-observer variance were comparable with the results obtained using manual planimetric techniques. Intra-observer variance for disc area was significantly larger for the less trained of the two experienced observers. Inter-observer variances were 0.004 +/- 0.009 mm2 for cup area, 0.008 +/- 0.013 mm2 for disc area and 0.009 +/- 0.014 mm2 for rim area. These inter-observer variances were significantly larger than those previously reported for manual planimetry. The absolute differences between the two observers ranged from -0.35 to +0.20 mm2 (-0.08 +/- 0.11 mm2) for cup area, from -0.38 to +0.15 mm2 (-0.08 +/- 0.11 mm2) for disc area and from -0.29 to +0.34 mm2 (-0.06 +/- 0.12 mm2) for rim area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗