Biomedical subjects

P Gresak

Publications and source records attributed to P Gresak.

3 recordsLinked to original sources

PubMed1992

False-positive magnetic resonance imaging of a metastatic carcinoma simulating a malignant melanoma.

Previous studies have shown the value of magnetic resonance imaging (MRI) in the diagnosis of malignant melanoma of the choroid. We describe the case of a patient with a choroidal mass whose MRI study was characteristic of malignant melanoma. Subsequently the eye was enucleated. However, on histopathologic examination, the mass was a metastatic carcinoma to the choroid. This false-positive study makes us question the value of MRI in the diagnosis of malignant melanoma of the choroid.

Aged↗

PubMed1991

Modified vitrectomy for impending macular holes.

We report a consecutive series of 13 eyes (11 patients) treated with pars plana vitrectomy, in which surgical manipulation of the prefoveal layer of cortical vitreous was avoided, for stage I (eight eyes) and stage II (five eyes) macular hole formation. Average follow up was 8.1 months (range, 2 to 13 months). There was no significant improvement in vision in the patients with stage II macular holes; however, vision in these patients stabilized and did not fall below 20/400. Visual acuity improved in seven of the eight patients with stage I holes. The results for both these groups achieved by our modified vitrectomy, which is relatively easy to perform and involves minimal intraoperative manipulation of the fovea, are consistent with those obtained by methods involving more aggressive cortical vitreous stripping of the fovea.

Aged↗

PubMed1990

Ocular toxicity of vitreal pluronic polyol F-127.

To evaluate pluronic polyol F-127 (PF-127) as a vitreous substitute and an intraocular drug delivery system, a total vitrectomy was performed on 18 New Zealand rabbits (18 eyes). The vitreous was replaced with either PF-127 (9 eyes) or balanced salt solution (9 eyes). There was little difference clinically between the eyes containing PF-127 and the control eyes. Both groups showed mild postoperative inflammation, with no differences in intraocular pressures. Histopathologic findings for the control group showed no significant retinal alteration, and serial ERG findings were within normal limits. In contrast, the eyes containing PF-127 showed marked destruction of the retina by 2 weeks after surgery. The ERG amplitudes decreased dramatically to a flat tracing by 24 hours after surgery. Although it is attractive as a potential vitreous substitute, PF-127 is not safe for human use, at least at the concentration used.

Animals↗