Edward L. Shaw

The Functional Reserve of Corneal Endothelium

With recent advances in our knowledge of corneal physiology, coupled with the development and increasing availability of the specular microscope as a clinical instrument, valid observations relating the morphologic appearance of the corneal endothelium to its functional capacity are within our reach. Manual methods of data analysis are cumbersome, time consuming, and associated with human error and investigator bias. The Omnicon pattern analysis system lends itself to objective analysis of morphologic features, offers the possibility of quantifying the data obtained and, hopefully, will lead to a better understanding of the many aspects of endothelial cell morphology which, in total, relate to the functional reserve of a given cornea.

Intraocular lens implantation combined with penetrating keratoplasty.

A restrospective analysis was conducted of 27 cases of penetrating keratoplasty associated with intraocular lens implantation. Although not statistically significant, the results indicated an 80% success rate when penetrating keratoplasty, cataract extraction and intraocular lens implantation were combined in a single operation. Secondary implantation of intraocular lenses in cases of previous keratoplasty were unsuccessful in all three cases.

Automated Pattern Analysis of Corneal Endothelium

A proper understanding of the endothelial cell morphology of the cornea is of great significance to the corneal surgeon. Specular microscopy allows direct visualization of endothelial cell morphology and a proper analysis of these data needs automated computerized type of systems. Automated pattern analysis seems to offer a good option in this direction. From our experience it appears that such systems can be used with great advantage in the analysis of endothelial cell morphology. The data obtained from such analysis help to develop some indices for various facets of endothelial cell morphology.

A technique for treating positive vitreous pressure during intraocular lens implantation in intracapsular surgery.

Positive vitreous pressure during intraocular lens implantation is treated by early recognition and instillation of an air bubble to deepen the anterior chamber, and subsequently to prevent contact between the intraocular lens and the corneal endothelium. A technique is presented which has proven successful in 20 cases.

The Castroviejo square graft: a retrospective study.

We examined 19 eyes of 12 patients who had undergone penetrating keratoplasty utilizing the Castroviejo square graft technique. The visual acuities at the time of examination for inclusion in the study ranged from 20/30 to counting fingers. Of the 19 original square grafts, eight were judged clear centrally with varying degrees of peripheral stromal haze, and one was hazy. The remaining eight failed with varying degrees of irreversible corneal edema. The eight corneas obtained following repeat penetrating keratoplasty were studied with light and electron microscopy. The donor/recipient corneal stromal lamellae were continuous at the graft-host junction, particularly in the mid-stromal area. Disruptions in Descemets membrane were present at the wound; transmission electron microscopy revealed differences in the composition of Descemets membrane between the graft and the host. Two additional square grafts had failed, and the patients were awaiting keratoplasty. Nine of the 19 grafts were judged functionally clear, with six of the nine requiring contact lens correction.

Radial Keratotomy-Reply

In Reply. —Our patient was first diagnosed as having keratoconus in 1962. This had advanced to keratoglobus by 1973. Following his right corneal transplant, the patient achieved 6/12 (20/40) visual acuity. Because of problems associated with a high-post keratoplasty astigmatism, central graft edema developed while the patient was wearing his contact lenses. At no time did the patient have evidence of diffuse epithelial pathologic characteristics. In our experience, this would be an example of a patient who would benefit from a relaxing corneal incision. One of us (P.S.B.) has performed 15 such procedures without any substantial effect on the anterior ocular surface. The surgeon in our case report (not one of the authors) was experienced in radial keratotomy at the time he performed the operation. Dr Thornton has stated that the use of a 2.5-mm optical zone is guaranteed to produce glare, flare, and halos. When this procedure was performed