Specular microscopic observation of eye-bank corneal endothelium using

the clinical specular microscope

Kazuo Tsubota, M.D. Kuniomi Abe

ABSTRACT A special holder for endothelial evaluation of

eye-bank corneas using the clinical specular microscope was developed. Using this holder, pictures of the corneal endothelium can be taken without the eye-bank specular microscope.

Key Words: corneal endothelium , donor evalua­tion, eye-bank cornea, specular microscope

Assessment of the viability of donor corneas prior to penetrating keratoplasty is essential for successful surgery. Although various methods have been devel­oped, such as noninvasive measurement of the metabolism of corneas by phosphorus magnetic resonance or redox fluorometry, 1,2 none of them are clinically used except specular microscopic observa­tion of the endothelium. 3

To take endothelial pictures of eye-bank corneas, a special eye-bank specular microscope is usually necessary. The eye-bank specular microscope is vertically designed to obtain the specular reflex from the endothelium of preserved corneas. We have developed two simple attachments to take pictures of the endothelium using the clinical specular micro­scope. One is a holder for the eye-bank cornea container, and the other is a magnification lens.

DESCRIPTION OF ATTACHMENTS

The holder is designed to keep the eye-bank container horizontal. It is easily attached to the chin

From the National Tochigi Hospital and Keio University School of Medicine, Department of Ophthalmology, Tochigi, Japan (Tsubota), and Konan Camera Research Institute, Inc. (Abe).

Reprint requests to Kazuo Tsubota, M.D., Department of Ophthalmowgy, Tokyo Dental College, 7-1 Sugano 6 chome, lchikawa-shi, Chiba, 272, Japan.

Fig. lAo (Tsubota) The holder for the eye-bank container. The diameter of the holder is the same as that of the container. The holder is attached to the chin rest of the specular microscope. The base can rotate hori­zontally or can be rotated vertically by adjusting the knob.

rest of the clinical specular microscope (Keeler Konan wide-field specular microscope) (Figure lA). This holder has an adjustable mount at the base that allows free movement of the container for obtaining the specular reflex. A knob controls the vertical direction, and the holder can rotate horizontally. The magnification lens, which is attached between the camera and microscope, magnifies the images projected by almost twice their original size and corrects the optical aberration produced (Fig-

Fig. lB. (Tsubota) The magnification lens is attached be­tween the camera and the microscope.

644 J CATARACT REFRACT SURG-VOL 16, SEPTEMBER 1990

Fig. 2A. (Tsubota) Specular microscopic photograph of por­cine corneal endothelium (18 hours after enuclea­tion) taken without the magnification lens. The endothelium is small. The number of cells can be counted, but detailed analyses such as morpho­metric analysis are difficult under this magnification. The right column is 200 JLm vertically.

Fig. 2B. (Tsubota) Specular microscopic photograph of por­cine corneal endothelium (same as preceding figure) taken with the magnification lens. The endothelial cells are large enough to evaluate. The right column is 100 JLm vertically.

ure IB). To photograph, the cone lens is removed and the eye-bank container is inserted into the holder.

The specular reflex can be obtained easily by adjusting the direction of the container. The endo­thelial image is too small when the magnification lens is not used (Figure 2A), but the image is clear and large enough to evaluate the endothelium (Figure 2B) when the magnification lens is used.

DISCUSSION

Many eye banks and corneal surgeons are begin­ning to take endothelial pictures to evaluate and

select donor corneas. Using the two attachments, the endothelial pictures of donor corneas stored in eye-bank containers can be taken with the clinical specular microscope. We think this is a simple and cost-effective substitute for the eye-bank specular microscope-one that can be afforded by any cor­neal specialist or eye bank.

REFERENCES

1. Greiner JV, Lass JR, Glonek T. Metabolic status offresh eye­bank-processed corneas; a phosphorus nuclear magnetic resonance study. Arch Ophthalmol1984; 102:1676-1677

2. Tsubota K, Laing RA, Chiba K, et al. Noninvasive metabolic analysis of preserved rabbit cornea. Arch Ophthalmol1988; 106:1713-1717

3. Matsuda M, Yee RW, Glasser DB, et al. Specular microscopic evaluation of donor corneal endothelium. Arch Ophthalmol 1986; 104:259-262

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