N O T E S , C A S E S , I N S T R U M E N T S

PROCEDURE FOR OBTAINING FLUORESCENT SEMICIRCLES

IN APPLANATION TONOMETRY

MASSIMO G. BUCCI, M.D.

Rome, Italy

The advantages of applanation tonometry over the other techniques used for the clini-cal evaluation of intraocular pressure have been widely acknowledged over the last 10 years.

One of the greatest difficulties encoun-tered when performing applanation tonome-try is that very often the fluorescent semicir-cles appear far too thick or, on the other hand, too threadlike, which results in an er-ratic evaluation of the intraocular pressure. This is mainly caused by an excessive or in-sufficient concentration of fluorescein in the lacrimal film.

Stabilized fluorescein-anesthetic solutions for applanation tonometry1-4 eliminate the need for a separate application of fluores-cein, but cannot prevent the formation of a lacrimal film that is too thick or an excessive dilution of the dye.

To eliminate these problems, the following apparatus has been developed.

The apparatus (Fig. 1) is made of plastic and consists essentially of a cylinder, shaped internally like a cone, which permits it to fit onto the tonometer prism (Fig. 2 ) .

At the extreme inside end of this cone is a pointed micro-applicator ( M ) . The degree of penetration into the cylinder is graduated and fixed by a screw ( S ) .

The micro-applicator receives a solution of fluorescein (1/10) by a capillary which soaks a felt filter (F ) and fills a reservoir ( R ) . The fluorescein can be diluted with an anesthetic substance of a suitable concentra-

From the University of Rome Eye Clinic, Rome, Italy.

Reprint requests to Massimo G. Bucci, M.D, University of Rome Eye Clinic, Rome, Italy.

C

Fig. 1 (Bucci). Schematic design of the prism (P) already placed inside the cylinder (C) at the base of which is seen the micro-applicator ( M ) . The micro-applicator is constantly soaked in fluo-rescein (1/10) through direct contact with a special filter (F) which is constantly supplied with the col-oring matter from the reservoir ( R ) . The amount the micro-applicator delivers into the cylinder is regulated by means of a screw ( S ) .

tion. A small fitted cover prevents the solution

from evaporating from the point of the mi-cro-applicator between one measurement and another.

By introducing the tonometer prism ( P ) into the cylinder and applying a slight pres-sure, one allows the point ( M ) to deposit a very small drop of the diluted coloring mat-ter onto the surface of the prism, covering an area of 0.5 to 1 mm diameter.

In this way, on contact between the outer

Fig. 2 (Bucci). Photograph of the apparatus.

1140

VOL. 71, NO. 5 NOTES, CASES, INSTRUMENTS 1141

surfaces of cornea and prism, one obtains two semicircles of a constant and even thick-ness, such as are required for a perfect to-nometry.

After the tonometry test, the first few blinks are sufficient to remove any traces of the coloring matter from the surface of the cornea. In fact, the coloring matter remains to a greater extent on the prism, making it possible to proceed directly to the tonometry of the contralateral eye.

SUMMARY

A new, simple device for obtaining the formation of fluorescent semicircles in ap-planation tonometry is described. The de-scription of the apparatus and the procedure are reported. Essentially, the technique con-sists of putting directly the exact amount of fluorescein, correctly diluted, on a very small area of the surface of the tonometer prism.

ACKNOWLEDGMENT

I thank Miss Linda Carol Boren for technical as-sistance.

REFERENCES

1. Grant, YV. M. : Fluorescein for applanation to-nometry: More convenient and uniform application. Am. J. Ophth. 55:1252, 1963.

2. Tanton, J. H. : Fluorescein-proparacaine hy-drocloride : Combination drops for applanation to-nometry. Am. J. Ophth. 58:1055, 1964.

3. Fenton, P. J. : Applanation tonometry using one drop of an anesthetic-fluorescein mixture. Brit. J. Ophth. 49:205, 1965.

4. Quickert, M. H. : A fluorescein-anesthetic so-lution for applanation tonometry. Arch. Ophth. 77 : 734, 1967.

ORBITAL BLOW-OUT FRACTURE REPAIR, CONJUNCTIVAL

APPROACH

RICHARD R. TENZEL, M . D , AND

GORDON R. MILLER, M . D .

Miami, Florida

The ease and effectiveness of the direct approach to the orbital floor has been well documented.1 3 A well-placed incision in the nasojugal fold leaves a minimal scar. How-ever, even a small scar may have a long-term adverse effect in certain patients. There is also the possibility of hypertrophic scar for-mation and in rare cases, keloid formation. These complications can be obviated by plac-ing the incision in the inferior cul-de-sac.

Cases with small- to medium-sized frac-tures may be repaired easily through a trans-conjunctival approach to the orbital floor. Patients with extensive floor fractures or those who require wiring of the orbital rim should be repaired through a skin incision. The use of preoperative orbital laminograms (Water's view) allows a selective surgical approach to the orbital floor.

TECHNIQUE

A local or general anesthesia may be used. A Desmarres retractor is used to retract the lower eyelid away from the globe (Fig. 1 ) . A malleable retractor, placed posterior to the orbital rim, gives adequate exposure. One in-cision is made to the orbital rim through all of the tissue layers, including the perios-teum. The prolapsed orbital fat is retracted with the malleable retractor. The periosteum is elevated and all herniated material is re-moved from the antrum (Fig. 2 ) . Loose

From the Ophthalmic Plastic Surgery Clinic, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida. This investi-gation was supported in part by USPHS Research Grant NB-05277 from the National Institute of Neurological Diseases and Blindness, Bethesda, Maryland.

Reprint requests to Richard R. Tenzel, M.D, 1100 N.E. 163rd Street, North Miami Beach, Flor-ida.