International Ophthalmology 20: 229230, 1996. 229 @ 1996 KluwerAcademic Publishers. Printed in the Netherlands.

Determining fluid level in a translucent eye-drop bottle: transi l lumination by penlight *

Ozcan Kaylkclo~lu, Cezmi Akkln & Halil Ates Department of Ophthalmology, Ege University School of Medicine, Izmir, Turkey

Accepted 26 July 1996

Key words: bottle, eye-drop, transillumination

Abstract

We describe an easy way to determine eye-drop contents in translucent bottles�9 Transillumination of eye-drop bottles from behind or the bottom by using a penlight clearly defines the fluid levels. The described procedure may prevent disposal of eye-drop bottles containing useful amounts of medication and prevent Ophthalmologists and Patients unexpectedly coming across an empty bottle.

Eye-drops are generally bottled in translucent contain- ers [1]. Practical ways to determine the presence of medication in a translucent eye-drop bottle are by sen- sation of fluid movement by shaking or testing the bottle at instillation. It may, unexpectedly, be empty at the time a patient is prepared for eye-drop instillation by extending the neck and pulling down the lower eye- lid. Bubbles may appear at the tip of the dropper but the result of drop instillation from this bottle will be in vain.

Transillumination is a method of examination by the passage of light through tissues or a body cavi- ty [2]. In ophthalmology, it is especially useful for retinal lesions, intraocular tumors and atrophy of the iris pigment layer [3-5]�9 Based on the same princi- ple, a penlight can be used to evaluate the contents of eye-drop bottles by transillumination. A penlight held in contact with the bottom or back of a translucent eye-drop bottle provides bright transillumination and adequate contrast to define the fluid level in that bot- tle. The examination of such an eye-drop bottle under daylight conditions does not transmit enough light to satisfactorily visualize its content. Drops in suspension form are better transilluminated because of their physi- cal properties which cause reduced light transmittance (Figure 1).

* The authors have no proprietary or financial interest related to the manuscript.

�9 Figure 1. Transillumination of an eye-drop bottle by using a penlight makes the fluid level visible and helps to determine the volume of its content.

230

A minimum level of fluid and even a few drops in a translucent container can be detected by penlight tran- sillumination. This may prevent the premature disposal of bottles containing beneficial amounts of medication. Foreign particles or bubbles can also be seen as dark shadows by the described method. Transillumination of eye-drop bottles by a penlight is a practical and simple way of informing ophthalmologists about the contents of eye-drop bottles.

References

1. The United States Pharmacopeia, The National Formulary. Rockville: The United States Pharmacopeial Convention Inc, 1989: 15704.

2. Hensyl WR (Ed.). Stedman's Medical Dictionary, 25th edition Williams and Wilkins Baltimore 1990, 1623.

3. Pavan-Langston D. Ocular examination techniques and diag- nostic tests. In: Pavan-Langston D (Ed.). Manual of ocular diagnosis and therapy. Boston: Little, Brown and Company 1991: 19.

4. Michels RG, Wilkinson CP, Rice TA. Retinal detachment. St Louis, The CV Mosby Company 1990: 365.

5. Frieberg TR. Examination of the retina: ophthalmoscopy and fundus biomicroscopy. In: Albert DM, Jacobiec FA (Eds.). Principles and practice of ophthalmology. Philadelphia, WB Saunders Company 1994: 696.

Address for correspondence: Ozcan. Kaylkclo~lu, Ege University

School of Medicine 35100 Bornova, Izmir, Turkey