Biomedical subjects

P H Akers

Publications and source records attributed to P H Akers.

5 recordsLinked to original sources

PubMed1983

Acute morphologic features of radial keratotomy.

We performed eight partially penetrating incisions in 19 eye-bank, 12 nonhuman primate, and 34 canine eyes. Evaluation of the posterior corneal surface by vital staining, correlative microscopy, with corneal incisions set from 80% to 110% of central pachymetric thickness, in three eyes demonstrated damage to the endothelium without anterior chamber perforation. Posterior folds in Descemet's membrane under an incision site was present in all specimens. Potential optical aberrations could be produced about the visual axis depending on the direction of the corneal incisions. Based on this study, the radial keratotomy procedure performed with up to eight deep incisions may produce optic defects. We recommend animal studies to assess the long-term effects of this procedure on the cornea and especially the endothelium.

Adult↗

PubMed1983

Refractive keratoplasty. Tissue dyes and cryoprotective solutions.

The cryoprotective dye solution KM-26 (0.25% kiton green, 8% glycerin, and 4% dimethyl sulfoxide), which is presently used for all lamellar refractive surgical procedures, was evaluated and compared to other dyes that can stain corneal tissue. With the use of canine and human eye bank tissue, we found kiton green and light green to produce the least tissue alteration and to destain readily. Glycerin with or without dimethyl sulfoxide or dye was deleterious to the endothelium in the area under the keratectomized recipient bed. On the basis of our findings, glycerin and dimethyl sulfoxide should be deleted from the cryoprotective solution and a 0.1% concentration of light green in balanced salt solution or M-K medium should be used and the frozen tissue should be thawed in a balanced salt solution or M-K medium to eliminate potential damage to the recipient corneal endothelium.

Animals↗

PubMed1983

Growth of cultured corneal endothelial cells onto a vitreous carbon matrix.

Fourth passage cells of a rabbit corneal endothelial line were grown for 1 week in flasks containing pieces of a reticulated vitreous carbon matrix. The rate of cell growth in flasks containing the matrix was consistent with that in control flasks. Small fragments of the vitreous carbon material lying on the flask floor were covered by the monolayers as the cells grew to confluency. Vertical growth of cells onto larger pieces of the matrix proceeded in a staged fashion with maximum cell density on pieces of the matrix closest to the floor of the flask. As defined by scanning electron microscopy, cell growth occurred to a level at least 600 microns above the floor of the flask and the confluent monolayer. This novel culture procedure should be a model situation for study of many different aspects of the in vitro capabilities of corneal endothelial cells.

Animals↗

PubMed1982

Refractive keratoplasty: microkeratome evaluation.

We performed routine microkeratome and freehand lamellar keratectomies in 65 canine eyes and 24 human eye-bank eyes. The microkeratome technique produced more predictable resections compared with the freehand technique and at the same time produced a wound that would allow for better wound coaptation. Neither technique damaged the corneal endothelium. We conclude that one of the reasons for the success of the refractive keratoplasty procedures is the refined microkeratome technique.

Animals↗

PubMed1982

Correlative microscopy and tissue culture of congenital hereditary endothelial dystrophy.

A 4 1/2-year-old boy with congenital hereditary endothelial dystrophy underwent successful bilateral penetrating keratoplasties. Visual acuity in both eyes was restored to 6/18 (20/60). Correlative microscopic analysis of the corneal button obtained from the first transplant showed an irregular epithelium, a continuously thickened Bowman's layer, fragmentation and homogenization of the anterior stromal lamellae, a mildly enlarged stromal fibril diameter, abnormal collagen layers posterior to Descemet's membrane, atrophic paracentral corneal endothelium, and absent central endothelium. The endothelial cells from the second corneal button were placed in tissue culture and failed to demonstrate any growth characteristics of differentiation into normal appearing cells after 14 days. We concluded that the endothelial cells in congenital hereditary endothelial dystrophy are functionally and morphologically abnormal. Early penetrating keratoplasty can be successful in such cases.

Cells, Cultured↗