PubMed Health⌕ Search

Biomedical subjects

J C Sanchez-Thorin

Publications and source records attributed to J C Sanchez-Thorin.

7 recordsLinked to original sources
PubMed1999

The BioMask for treatment of corneal surface irregularities with excimer laser phototherapeutic keratectomy.

PURPOSE: To assess the characteristics of BioMask as a potential masking agent for use with the excimer laser. METHOD: We addressed ablation rate, smoothness, ease of use, dioptric shift, treatment of standardized irregular topography, and ability of BioMask to induce dioptric change in vivo. RESULTS: BioMask ablates at a rate of 0.28 microm per pulse. The BioMask conforms to the base curve of a contact lens in the excimer blank, eye bank eye, and rabbit eye with a r2 of 0.9982, 0.9844, 0.9858, respectively. We are readily able to create 20 diopters of flattening or steepening (r2 = 0.9944). Standardized irregular topography generation in the rabbit eye and then removal with BioMask was successful. The central corneal topography of the rabbit cornea showed predictable changes with various contact lens base curves with the BioMask (r2 = 0.875). CONCLUSIONS: BioMask has excellent potential as an ablatable mask material in the treatment of superficial corneal scars.

Animals↗
PubMed1997

The Tampa Trephine technique with cat corneal endothelium.

The Tampa Trephine (Martin Marietta Speciality Components, Largo, FL, U.S.A.) penetrating keratoplasty technique uses a 7.0-mm corneal donor button with six rectangular 1 x 2-mm tabs of Bowman's layer, 75 microns in thickness, which are inserted into the recipient stroma beneath Bowman's layer. We evaluated the safety of the Tampa Trephine tissue-trephination method on the cat corneal endothelium combining vital staining and scanning electron microscopy, comparing it with the standard Weck trephination technique. The Tampa Trephine tissue trephination produces a donor button with a 6.7-mm diameter central area of normal endothelium. Localized peripheral areas of cellular loss, endothelial and Descemet's tears, endothelial detachment, and folding along the border of the trephination were observed with the Tampa Trephine method, all located in an area of < or = 150 microns, adjacent to the edge of the button. Standard trephination induced a localized peripheral area of endothelial damage < 50 microns in extension from the donor edge. A theoretic maximal 8.4% peripheral endothelial cell loss is induced with the Tampa Trephine trephination method, compared with a 2.8% loss with the standard procedure. The peripheral location of the alterations after the Tampa Trephine does not hinder the viability of the corneal endothelium, as it has been clinically observed.

Animals↗
PubMed1991

Myopic keratomileusis in situ: a preliminary report.

We describe a technique and report a retrospective evaluation of myopic keratomileusis in situ. Surgery was performed on 32 eyes, with a mean follow-up time of 128.7 days (range 90 to 194 days). The average reduction of myopia was 8.48 diopters (D) when measured by refraction and 3.96 D by keratometry (minor axis). A statistically significant Pearson correlation coefficient of 0.49 (P = .01) was found between these two variables. Postoperative mean manifest spherical equivalent was -1.70 D (standard deviation 2.54 D). Mean cylinder correction increased -0.48 D (range -2.25 to 2.00 D). Uncorrected visual acuity improved after surgery in all eyes, but in 14 eyes the best corrected visual acuity diminished. Multiple regression model disclosed a limited predictability of the technique. Complications included diminution of best corrected visual acuity, under- and overcorrections, increase in keratometric astigmatism and cylinder correction, keratitis, delayed corneal epithelialization, interface amorphous deposits, monocular diplopia, interface epithelialization, and opacification. The most frustrating was an elusive postoperative cycloplegic refraction. In our hands, myopic keratomileusis in situ was not a technically safe, precise, and predictable technique for correction of myopia. Further improvement in the technique and equipment may provide better results.

Adult↗