Surgery and Healing in the Developing World - Dartmouth-Hitchcock

Ophthalmology
Figure 2. Refractive errors.
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External Examination
The lids should be checked for symmetry, ptosis, inflammation and swelling.
Conjunctivae should be inspected in good light and any inflammation or
sub-conjunctival hemorrhage noted. Corneal opacity and edema should be assessed
using the light from your ophthalmoscope. Corneal abrasions and ulcers can be
detected using 1% fluorescein drops. The pupils should be examined for equal size
and reaction to light and accommodation. Finally the lens should be inspected for
any opacity (found in cataracts).
Eye Movements
The patient should be asked to focus on the tip of a pen, or similar object, and to
indicate if they experience blurring or double vision (diplopia) at any time. The pen
should then be moved up, down, left and right then diagonally between these positions
(Fig. 3). If diplopia is experienced the site at which it is most severe should be
recorded.
Squints
Testing for squints (strabismus) is conducted initially by shining a torch between
the eyes. The reflection of light should be in the same position relative to the pupil
in both eyes. If this is not the case, a squint is present. A cover test can also be
perfomed (covering each eye alternately). A manifest squint is detected if the uncovered
eye moves as the other eye is covered. A latent squint is detected if the covered
eye moves when its cover is removed.
Treatment is initially aimed at correcting any refractive errors that may be present.
If this fails to correct the squint, the good eye may be patched to encourage the use
of the squinting eye. (NB Never patch an eye for more than 2 hours per day in a
child under 7 years old.) If this also fails, referral for surgery is appropriate.
Correction of a squint is vital before 2 years of age as after this time permanent
neurological changes will have taken place causing the “bad” eye to become lazy.
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