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Biomedical subjects

N E Engelbrecht

Publications and source records attributed to N E Engelbrecht.

5 recordsLinked to original sources

Indocyanine green effect on cultured human retinal pigment epithelial cells: implication for macular hole surgery.

PURPOSE: To evaluate potential toxic effects of indocyanine green dye on cultured human retinal pigment epithelial cells. METHODS: Controlled laboratory experiment. Cultured human retinal pigment epithelial cells were exposed to balanced saline solution, balanced saline solution with endoillumination, indocyanine green or indocyanine green with endoillumination. Cells were evaluated by light microscopy, electron microscopy, and a mitochondrial dehydrogenase assay. RESULTS: Retinal pigment epithelial cells exposed to indocyanine green showed no histologic or ultrastructural changes. Those exposed to indocyanine green alone or indocyanine green plus light demonstrated a significant decrease in mitochondrial enzyme activity (P = 0.0002 and 0.005, respectively). CONCLUSION: Brief exposure of cultured human retinal pigment epithelial cells to indocyanine green results in decreased mitochondrial enzyme activity but does not appear to influence cellular morphology or ultrastructure.

Cells, Cultured↗

Combined intraepithelial squamous neoplasia and atypical fibroxanthoma of the cornea and limbus.

PURPOSE: To investigate a case of an unusual neoplasm of the cornea and limbus. METHODS: A 59-year-old man presented with a highly vascularized, nodular mass involving the left cornea and limbus. An excisional biopsy and, subsequently, a superficial lamellar keratectomy and multiple conjunctival biopsies were performed. At the 6-month follow-up examination, repeat conjunctival biopsies were performed. RESULTS: Histopathologic examination of the corneal specimen showed a high-grade intraepithelial squamous neoplasia (in situ carcinoma) overlying an atypical fibroxanthoma. CONCLUSION: We report the clinical and histologic appearance of a corneal/limbal neoplasm consisting of an intraepithelial squamous neoplasia and an atypical fibroxanthoma.

Carcinoma in Situ↗

5-Fluorouracil for the treatment of intraepithelial neoplasia of the conjunctiva and cornea.

OBJECTIVE: To evaluate the efficacy of pulse dosing of topical 5-fluorouracil (5-FU) in the treatment of conjunctival and corneal intraepithelial neoplasia. DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Seven patients with histologic evidence of intraepithelial neoplasia were identified by conjunctival biopsy or tumor excision. METHODS: Seven patients with a minimum of 7 months of follow-up were treated with pulsed dosing of 1% 5-FU. Topical 1% 5-FU was administered four times daily for 2 to 4 days for each cycle. The number of initial treatment cycles was two to six, with the time between cycles being 30 to 45 days. MAIN OUTCOME MEASURES: The presence or absence of clinically evident intraepithelial neoplasia was evaluated after each treatment interval. Patients were also monitored for adverse reactions to the use of topical 5-FU. RESULTS: Four patients remain disease free with a mean follow-up of 18.5 months (range, 7-36 months) with no additional treatment after the initial treatment cycles (mean, 3.75 cycles; range, 2-5 cycles). Three patients had recurrence of disease after the initial treatment cycles. Two patients were treated with additional cycles for recurrent disease (six cycles in one patient and five cycles in the other patient) and are free of disease at 20 and 21 months after treatment, respectively. One patient had persistent disease despite treatment with topical 5-FU and was treated with topical mitomycin C with resolution of the disease without recurrence for 16.5 months. No adverse reactions to pulse dose treatment with topical 5-FU were noted. CONCLUSIONS: Pulsed dosing with 1% topical 5-FU for the treatment of conjunctival and corneal intraepithelial neoplasia, alone or as an adjunct to excision of bulky disease, is a well-tolerated and effective method of treatment.

Administration, Topical↗

Intraocular foreign bodies: management, prognostic factors, and visual outcomes.

OBJECTIVE: To determine prognostic factors and visual outcomes in patients with intraocular foreign bodies (IOFBs). DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Fifty-nine consecutive patients undergoing removal of an IOFB with a minimum of 6 months of follow-up. INTERVENTION: Surgical removal of the IOFB and repair of associated ocular trauma. MAIN OUTCOME MEASURES: Final best corrected visual acuity was the main outcome measured. Ocular findings at presentation were compared with final visual acuity to determine prognostic factors for visual outcome. RESULTS: Final best corrected visual acuity of 20/40 or more was obtained in 42 patients (71%) and ambulatory vision (>5/200) was achieved in 50 patients (85%). Presenting visual acuity was predictive of final visual outcome (P < 0.01). Prognostic factors for a better visual outcome (P < 0.05) included better presenting visual acuity and hammering metal on metal as the mechanism of injury. Prognostic factors for a poor outcome (P < 0.05) included poor presenting visual acuity, the presence of an afferent pupillary defect, and vitreous hemorrhage. CONCLUSIONS: Final visual outcomes were excellent in 71% of patients. Presenting visual acuity was the strongest predictor of final visual outcome in this series. Additional predictive factors included the mechanism of injury, the presence of an afferent pupillary defect, and vitreous hemorrhage.

Adolescent↗