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Biomedical subjects

P R Egbert

Publications and source records attributed to P R Egbert.

At least 19 recordsLinked to original sources
PubMed2005

Onchocerciasis: a potential risk factor for glaucoma.

BACKGROUND: Onchocerciasis is a microfilarial disease that causes ocular disease and blindness. Previous evidence of an association between onchocerciasis and glaucoma has been mixed. This study aims to further investigate the association between onchocerciasis and glaucoma. METHODS: All subjects were patients at the Bishop John Ackon Christian Eye Centre in Ghana, west Africa, undergoing either trabeculectomy for advanced glaucoma or extracapsular extraction for cataracts, who also had a skin snip biopsy for onchocerciasis. A cross sectional case-control study was performed to assess the difference in onchocerciasis prevalence between the two study groups. RESULTS: The prevalence of onchocerciasis was 10.6% in those with glaucoma compared with 2.6% in those with cataracts (OR, 4.45 (95% CI 1.48 to 13.43)). The mean age in the glaucoma group was significantly younger than in the cataract group (59 and 65, respectively). The groups were not significantly different with respect to sex or region of residence. In models adjusted for age, region, and sex, subjects with glaucoma had over three times the odds of testing positive for onchocerciasis (OR, 3.50 (95% CI 1.10 to 11.18)). CONCLUSIONS: This study has shown a positive association between subclinical onchocerciasis and glaucoma. This finding emphasises the importance of eradication of onchocerciasis from west Africa.

Age Distribution↗
PubMed2001

Diode laser transscleral cyclophotocoagulation as a primary surgical treatment for primary open-angle glaucoma.

OBJECTIVES: To evaluate the feasibility of diode laser transscleral cyclophotocoagulation (TSCPC) as a primary surgical treatment for primary open-angle glaucoma and to compare 2 laser energy settings used for treatment. METHODS: In a prospective clinical trial in Cape Coast and Accra, Ghana, 1 eye of each of 92 patients with primary open-angle glaucoma was treated by diode laser TSCPC as a primary surgical treatment. Eyes were randomly assigned to receive treatment by 20 applications of either 1.5 W applied for 1.5 seconds or 1.25 W applied for 2.5 seconds. RESULTS: Seventy-nine (86%) of 92 patients completed 3 months of follow-up; follow-up was 13.2 +/- 6.0 months (mean +/- SD). Intraocular pressure decreased in 53 (67%) of the 79 eyes. The drop in intraocular pressure was 20% or more in 37 eyes (47%) and final intraocular pressure was 22 mm Hg or less in 38 eyes (48%). An atonic pupil was a previously unreported complication that arose in 27 (28%) of 92 eyes. There were no serious complications of hypotony, phthisis bulbi, or sympathetic ophthalmia. Visual acuity decreased in 18 (23%) of 79 eyes treated by TSCPC and in 10 (23%) of 47 fellow eyes treated only with glaucoma medications. There was no difference in outcomes between the 2 laser energy settings. CONCLUSIONS: Diode laser TSCPC is a practical, rapid, well-tolerated procedure that may provide a modest and variable lowering of intraocular pressure. The treatment, used with conservative energy levels applied to the eye, seems to have few serious complications, although a previously unrecognized complication of atonic pupil needs further evaluation. A moderate variation in laser energy settings does not influence the results of treatment.

Adult↗
PubMed1998

Risk of hypotony after primary trabeculectomy with antifibrotic agents in a black west African population.

PURPOSE: To evaluate the risk of hypotony and hypotony maculopathy following trabeculectomy with 5-fluorouracil (5-FU) and mitomycin C (MMC) in a black West African population. METHODS: One hundred and one eyes of black Ghanaian patients with advanced primary open-angle glaucoma received intraoperative antifibrotic therapy with trabeculectomy as part of two randomized clinical trials. Overall, 57 patients received 5-FU (50.0 mg/ml for 5 minutes) and 44 received MMC (0.5 mg/ml for 3.5 minutes). All cases were performed by one of five surgeons at a single outpatient surgery center. RESULTS: Two of 101 eyes had a final intraocular pressure (IOP) of less than 5 mm Hg and were thus classified as having hypotony. No patient in either group was noted to develop hypotony-related maculopathy. Overall mean pre- and postoperative IOPs were 30.1 and 15.9 mm Hg, respectively. The patients receiving intraoperative MMC had a lower mean postoperative IOP (14.7 mm Hg) than those receiving 5-FU (first study, 17.1 mm Hg; second study, 16.7 mm Hg; p = 0.05). Mean overall follow-up was 17.7 months and did not differ significantly between the MMC and combined 5-FU groups. CONCLUSION: Hypotony following trabeculectomy supplemented with antifibrotic agents is a rare complication in this population. No eyes in either clinical trial developed hypotony maculopathy, suggesting that the prevalence of this condition is substantially lower in black West Africans than in whites.

Fluorouracil↗
PubMed1997

Trabeculectomy with intraoperative 5-fluorouracil vs mitomycin C.

PURPOSE: To compare the effectiveness of intraoperative 5-fluorouracil (5-FU) and mitomycin C used adjunctively with trabeculectomy in a black West African population. METHODS: Eighty-five consecutive eyes of 85 black patients undergoing primary trabeculectomy for open-angle glaucoma were prospectively randomly assigned to receive either 5-FU (50 mg/ml for 5 minutes) or mitomycin C (0.5 mg/ml for 3 1/2 minutes) intraoperatively by soaked sponge. RESULTS: Of the 81 eyes with at least a 3-month postoperative follow-up, 41 of 44 (93.2%) in the mitomycin C group and 27 of 37 (73.0%) in the 5-FU group had a final intraocular pressure of less than 21 mm Hg (P = .01). Twenty-eight of 44 eyes (63.6%) in the mitomycin C group and 18 of 37 (51.4%) in the 5-FU group had a final intraocular pressure of less than 15 mm Hg (P = .26). Mean postoperative intraocular pressure was 13.7 mm Hg in the mitomycin C group and 16.3 mm Hg in the 5-FU group (P = .05). There were no differences between the two groups in mean age, preoperative intraocular pressure, postoperative visual acuity, and complications. Mean follow-up was 10.0 +/- 4.41 months (range, 4 to 19 months). CONCLUSIONS: The adjunctive use of mitomycin C with trabeculectomy is equally safe and more efficacious compared to 5-FU in this West African population. Use of mitomycin C in this study was not associated with a statistically significantly greater proportion of patients achieving low intraocular pressure (less than 15 mm Hg) compared to 5-FU.

Antimetabolites↗
PubMed1993

A prospective trial of intraoperative fluorouracil during trabeculectomy in a black population.

In a study population of black Africans with advanced glaucoma in Ghana we conducted a prospective study of intraoperative 5-fluorouracil alone. Eyes undergoing trabeculectomy were randomly selected either to receive or not receive a single intraoperative application of 5-fluorouracil (50 mg/ml for five minutes). Fifty-five eyes had a mean follow-up of 282 days (minimum, 92 days). Twenty of 24 eyes (83%) in the 5-fluorouracil group vs 12 of 31 eyes (39%) in the control group had postoperative intraocular pressure of 20 mm Hg or less with or without medical therapy (P = .01). Eleven of 24 eyes (46%) in the 5-fluorouracil group and five of 31 eyes (16%) in the control group had intraocular pressure of 15 mm Hg or less (P = .02). Without medical therapy, 17 of 24 eyes (71%) in the 5-fluorouracil group and ten of 31 eyes (32%) in the control group had intraocular pressure of 20 mm Hg or less (P = .02). The overall complications were similar in the two groups. In this population, intraoperative 5-fluorouracil markedly improved the ability of trabeculectomy to lower intraocular pressure. We recommend that intraoperative 5-fluorouracil be considered in glaucoma surgery with poor prognosis as an alternative to postoperative subconjunctival injections when multiple injections are not feasible.

Adult↗
PubMed1992

Histologic study of healing after ab interno laser sclerostomy.

We examined the histologic characteristics of healing after ab interno laser sclerostomy in a human eye. A KTP 532 green laser coupled to a 300-microns quartz fiberoptic probe was used to create an ab interno sclerostomy in a terminally ill patient with pigmentary glaucoma. The intraocular pressure increased five days postoperatively and did not respond to medical treatment. The patient died six weeks postoperatively of metastatic lung cancer. Histopathologic analysis showed a patent 150-microns scleral lumen from the anterior chamber to the episclera, surrounded by a 300-microns zone of acellular thermal damage. There was no healing of the lumen. The subconjunctival end of the lumen was capped with a thick episcleral scar, which caused the failure of the operation.

Cicatrix↗
PubMed1991

Results of extracapsular cataract surgery and intraocular lens implantation in Ghana.

Neither outpatient surgery nor intraocular lenses have been widely used in developing countries. We performed extracapsular cataract extraction with posterior chamber intraocular lens implantation in a simple outpatient clinic in Ghana, West Africa. Forty-nine (64%) of 77 eligible patients with follow-up times of 12 to 29 months after surgery underwent an eye examination and an interview related to activities of daily life. Preoperative visual acuity was counting fingers or worse in all but one patient. Visual acuity improved in 44 patients (90%) after surgery. Twenty-six patients (53%) had a corrected visual acuity of 20/40 or better, 11 (22%) had a corrected visual acuity of 20/50 to 20/100, and 12 (25%) had a corrected visual acuity of 20/200 or worse. Subjectively, 94% of patients believed that their vision improved after surgery. No major late complications occurred following the immediate postoperative period. In addition, our population experienced no complications attributable to the outpatient format of this surgery. Every patient, all of whom lived within a 32-km radius of the clinic, reliably returned for postoperative appointments. Our results demonstrate that outpatient surgery may be a safe and practical alternative to routine hospitalization for eye surgery in developing countries.

Adult↗
PubMed1991

Intraocular involvement with subretinal pigment epithelium infiltrates by mycosis fungoides.

We report a case of intraocular mycosis fungoides in a 48-year-old man. The patient presented with decreased visual acuity, white subretinal lesions, and vitritis. Post-mortem histopathology revealed malignant T cell infiltrates consistent with mycosis fungoides in the retina, vitreous, and between the retinal pigment epithelium (RPE) and Bruch's membrane Focal atrophy of the RPE, along with the sub-RPE infiltrates, correlated with the clinically visible fundus lesions.

Bruch Membrane↗
PubMed1990

Treatment of refractory orbital pseudotumors with pulsed chemotherapy.

Five patients with orbital pseudotumor refractive to initial therapy are discussed. Three had a destructive granulomatous process associated with a sclerosing component. Two exhibited a predominantly lymphocytic infiltration. Chemotherapy with Prednisone (100 mg/day) and either Cytoxan (100 mg/day) or Chlorambucil (10 mg/day) in 5-day pulses is described. All patients responded clinically to this treatment without unfavorable side effects.

Adult↗
PubMed1989

Aggressive management of second primary tumors in survivors of hereditary retinoblastoma.

Survivors of hereditary retinoblastoma are at increased risk for the development of second primary tumors, most commonly osteosarcoma. Recent molecular genetic data demonstrate that a pleiotrophic effect of the retinoblastoma gene may be responsible for the development of these sarcomas. This report describes the incidence of second nonocular malignancies among 53 infants seen at Stanford University Medical Center who have been followed a median of 11.7 years. Of these, 42 initially had bilateral disease and eleven had unilateral disease. Of 53 infants, 50 received irradiation either as part of the initial therapy or as treatment for recurrent disease. The actuarial survival for the entire group is 67% at 30 year follow-up with a median survival of 79% at 11.7 years. Eight patients developed eleven second primary tumors. All occurred in the group having hereditary retinoblastoma. Eight were within the previously irradiated field and three were at distant sites. The second tumors included seven osteosarcomas, one angiosarcoma, one rhabdomyosarcoma, one malignant fibrous histiocytoma, and one unclassifiable round blue cell tumor. The actuarial incidence of the development of a second primary malignancy was 6% at 10 years, 19% at 20 years, and 38% at 30 years. The latent period from treatment of retinoblastoma to the diagnosis of malignancy ranged from 5.2 years to 36.2 years (median 16 years). An aggressive approach with combined modality therapy including radical resection, re-irradiation and/or chemotherapy was used to treat these second primary tumors in five of eight patients. In four of the five, there was no evidence of disease at 22-72 months following treatment. In the three patients who did not receive aggressive combined treatment, there were no survivors. These data confirm the previously reported risk of developing a second primary tumor among survivors with hereditary retinoblastoma. Careful long-term follow-up for this genetically susceptible group is essential for early detection and implementation of curative therapy.

Bone Neoplasms↗
PubMed1989

Internal suture occlusion of the Molteno glaucoma implant for the prevention of postoperative hypotony.

The Molteno glaucoma drainage implant procedure is useful for managing refractory glaucoma, but a significant concern has been the avoidance of postoperative hypotony due to temporary excessive filtration. We have developed a method of temporarily closing the translimbal tube with an internally-placed occluding suture (4-0 or 5-0 chromic). Seven to 12 days later this suture was removed, without surgery, in an outpatient setting. We have used this method on 30 patients. The advantages are that postoperative hypotony is reduced, and the Molteno drainage implant can be inserted in a single operation.

Drainage↗
PubMed1986

Ophthalmic disease in Western Samoa.

Since the last report on eye disease in Western Samoa in 1959 by Dr. Elliott, the population has increased from 97,000 to 158,000. The country now has a full-time ophthalmologist but could benefit from a larger eye care service. The distribution of disease is very similar to that found in 1959, with pterygium, cataract and injuries comprising the most frequent eye problems. Acute angle-closure glaucoma is much more common than open-angle glaucoma and is associated with a plateau iris configuration.

Cataract↗
PubMed1985

Radiotherapy of lymphoid diseases of the orbit.

Thirty-two patients with orbital pseudotumor (18), reactive lymphoid hyperplasia (2), atypical lymphoid infiltrate (4) or malignant lymphoma (8) were treated in the Division of Radiation Therapy at Stanford University between January 1973 and May 1983. Of the 20 patients with pseudotumor or reactive lymphoid hyperplasia, 10 had unilateral lesions and 10 had bilateral lesions. Biopsy samples were obtained in 15 patients; in five patients with bilateral disease the diagnosis was made on the basis of computed tomography (CT) and clinical findings. The majority of patients were referred because of disease refractory to treatment with corticosteroids. The patients were given a mean dose of 2360 rad using complex, individualized megavoltage techniques including lens shielding. Radiotherapy was well tolerated with no significant acute or late complications. Fifteen patients had complete resolution of symptoms after treatment; five had continued symptoms. Of the 12 patients with malignant lymphoma or atypical lymphoid infiltrate, four had systemic lymphoma with orbital involvement and eight had orbital involvement only. The diagnosis was made by biopsy in all patients and immunophenotyping was done in six cases, of which 5 were monoclonal. Patients were evaluated with a chest radiograph, lymphogram or abdominal CT, bone marrow biopsy and orbital CT. A mean dose of 3625 rad was delivered to the orbit only. Most of the patients received complex megavoltage treatment using bolus. All patients in this group had a complete response and local control. There were no relapses in those with localized disease. Two patients developed cataracts. Carefully planned orbital radiotherapy provides local control without symptomatic sequelae for orbital masses ranging from pseudotumor to malignant lymphoma.

Adult↗
PubMed1984

Alpha-interferon administration in cytomegalovirus retinitis.

Four patients, including three with the acquired immunodeficiency syndrome (AIDS), were treated with high-dose, buffy coat-derived alpha-interferon for progressive cytomegalovirus retinitis. Two of these patients had decreased viruria during therapy and the other two had increased viruria. There was evidence of progression of disease despite therapy in all patients, although the retinitis eventually became quiescent in the patient without AIDS. The severe immunosuppression encountered in AIDS patients complicates the management of cytomegalovirus and other opportunistic infections.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Ocular albumin fluorophotometric quantitation of endotoxin-induced vascular permeability.

Bacterial endotoxin (lipopolysaccharide; LPS) is known to alter systemic vascular permeability, but this effect is difficult to monitor and quantitate in vivo. The ocular vessels of the rabbit are particularly sensitive to LPS. Using a slit lamp equipped with a fluorophotometer, we have adapted a method to quantitate endotoxin-induced ocular vascular permeability by measuring the accumulation of fluorescein isothiocyanate-conjugated albumin into the anterior chamber of the eye. After intravenous administration of Salmonella typhimurim LPS, the anterior chamber fluorescence and blood fluorescence were measured at intervals of 15 min and 1 h, respectively, over 4 h. In controls, maximal fluorescence in the anterior chamber was 3.1 +/- 0.8% of blood fluorescence. Doses of LPS as low as 0.25 mug/kg produced an ocular/serum fluorescence ratio of 17.6 +/- 4.9. A dose of 2.5 mug of LPS per kg tended to produce a higher ratio (68.0 +/- 7.1) than a larger dose of 50 mug/kg (30.5 +/- 16.6). Permeability changes began within 30 min after LPS, and the rate of dye accumulation varied over time, with maximal leakage usually occurring 90 min after LPS, but occasionally occurring much later. Repeated doses produced tolerance. By conjugating albumin to rhodamine and utilizing a second filter with the slit lamp to measure accumulation of this dye, we demonstrated the persistence of marked permeability during a period when intraocular fluorescein isothiocyanate and albumin levels were relatively constant. This methodology indicates that extremely low doses of LPS induce ocular permeability changes and that neither the time course nor the dose response of this effect is linear. Ocular fluorophotometry is a sensitive, noninvasive technique to study the dynamics and pharmacology of LPS-induced permeability changes.

Animals↗
PubMed1981

Nosematosis of the cornea. Case report, including electron microscopic studies.

A 26-year-old woman underwent enucleation of a blind, painful eye because of a perforated corneal ulcer. Histopathologic examination of the eye disclosed an acute, necrotizing keratitis surrounding myriad small (2.5 to 3 x 4.5 to 5 micrometer), oval, faintly visible structures. Under polarized light, they were partially birefringent and stained intensely positive with the acid-fast technique. The organisms were located mainly within the cytoplasm of histiocytes in the deep corneal lamellae. They were interpreted as a protozoa of the genus Nosema. The diagnosis was confirmed by electron microscopic studies. The distinguishing features between Nosema species and Encephalitozoon are discussed. To our knowledge, this is the second documented case of corneal nosematosis.

Adult↗