Surgery and Healing in the Developing World - Dartmouth-Hitchcock

CHAPTER 1
CHAPTER 33
Ophthalmology
James Kerr and Christine A. King
Introduction
In the developed world the field of ophthalmology utilizes many high-tech therapies.
The advances of modern technology enable us to correct previously disabling
conditions through the use of lasers and ultrasound. These advances are of benefit to
many but cannot compare with the benefits offered by patching a lazy eye or correcting
myopia with glasses. In areas where people have been deprived of these services,
it is the simple interventions that make the difference.
This chapter is designed to help medical professionals with little ophthalmic
knowledge make the most out of whatever materials are available. This chapter describes
the basic procedure for eye examination with details on how to handle patients
who use different languages. Common causes of the red eye are explained and
ophthalmic emergencies highlighted. Simple procedures for making glasses and
eye-drops are described and equipment recommended. To conclude, the basics of
eye surgery are discussed and three operations described.
Examination
Any member of the team who is familiar with these methods can perform the
eye-exam. It is often helpful to train others to conduct this exam as it is easily performed
and can isolate the majority of ophthalmic pathologies. As with any examination
a full history will help to determine the areas on which to focus the exam.
Important factors to elucidate include trauma, irritation and pain, visual impairment
or loss, and the speed of onset of these symptoms.
The examination itself can be divided into: visual acuity, external examination,
extraocular movement and ophthalmoscopy.
Visual Acuity
Visual acuity should be assessed initially in the right eye, then repeated for the
left. The patient’s hand may be used to obscure the untested eye. Care should be
taken that the palm of the hand is used as patients may peep through their fingers.
Glasses should be worn if they are normally used. Acuity is measured using a Snellen
chart traditionally at a distance of 6 meters (20 feet). Charts are available in many
languages and varying sizes (e.g., half size which should be read at 3 meters), however
the most universal chart is one based on symbols not characters. One symbol
that is commonly used is a “c”, the break in the black circle being rotated so it is
facing up, down, left or right. The perceived direction is indicated to the examiner
using simple hand gestures (Fig. 1).
Surgery and Healing in the Developing World, edited by Glenn Geelhoed.