Charles J. Koester

The Barrier Function in Extracapsular Cataract Surgery

The distribution of fluorescein between the anterior chamber and the anterior vitreous was measured in two groups of patients after oral administration: group I, extracapsular cataract extraction (ECCE) patients with intact capsule and posterior chamber intraocular lens (PC IOL) (n = 12); group II, intracapsular cataract extraction (ICCE) patients with anterior chamber IOL (AC IOL) (n = 13). The fluorescein concentrations were measured by fluorophotometry and the penetration ratios were calculated. The penetration of fluorescein into the anterior vitreous was significantly less in the ECCE group (group I, penetration ratio = 2.03 +/- 1.00 X 10(-3) min-1; group II, penetration ratio = 5.99 +/- 4.89, X 10(-3) min-1, P less than 0.01). The authors concluded that in ECCE versus ICCE a significantly smaller proportion of fluorescein is found in the anterior vitreous relative to the aqueous after passage through the blood-aqueous barrier. This suggests a barrier to posterior movement of other molecules that may initially gain access to the eye in the anterior segment (e.g., prostaglandins).

INTRAOCULAR TEMPERATURE CHANGES PRODUCED BY LASER COAGULATION

The developments of the past 20 years have provoked a great interest in the intraocular temperature changes induced by radiant energy. The irreversible protein changes associated with heat make the temperature study an urgent one. Previously, clinicians were familiar with occasional retinal coagulations produced by accidental exposure to the sun. Recently, however, retinal damage also has been produced by the radiant energy from atomic explosions. The research contributions of Guerry et al. (1-3) and the extremely versatile instrument developed by Meyer-Schwickerath (4) have made photocoagulation an accepted clinical procedure. In the past year, optical masers have proven to be of potential value in the field of photocoagulation. A complete study of the temperature effects should include measurements in several areas. The temperature at the site of photocoagulation in the choroid must be determined together with the temperature ranges in various areas of the vitreous. Different zones of the vitreous must be selected because these zones are characterized by varying densities of radiant energy. Finally, scattered heat effects in the plane of the retina must be evaluated.

RETINAL COAGULATION: CLINICAL STUDIES*

Photocoagulation of the retina has become an accepted procedure in clinical ophthalmology. More recently the developments in the field of laser technology have held great promise for the clinician. Laboratory studies have already defined the characteristics of laser coagulations. In this investigation the clinical procedures and results will be described for a significant number of patients with a variety of retinal diseases. Equipment

Normal-eye-reduplicating spectacles for cosmetizing the exenterated patient

Currently, the orbitally exenterated patient has the choice of (1) a black patch or (2) a totally non-motile but costly, molded and customized prosthesis. The device presented here consists of a non-customized (except for the patients refraction) internally-reflecting lens-mirror-prism system for imaging the normal, retained eye, reducing said image to a small size, transmitting the minified image over to the exenterated side, and remagnifying, re-positioning and re-shaping it (by means of high cylinder and prism lenses) so that the observer sees the reduplicated eye together with the original view of it, as if it were two separate eyes.Motility is both present and complete, as seen from the exenterated side; and coloration and tissue contour are reproduced faithfully by reflection, so that even if the patient changes his complexion, as through sun tanning or induced pallor from chemotherapy, anemia, etc., hue will still be the same bilaterally. This device, patented in the USA, is not yet available; but...