and the epithelium over the spots is intact. Discontinuing lens use can usually resolve the problem quickly, but clinicians often prescribe an antibiotic, even though cultures tend to show no growth. Sterile infiltrates are also characterized by their small size.

Dry Eye

Evaluating a patient for dry eye should be part of the prefitting eye examination. A properly fitting lens rides on the tear film, which is essential for comfort and allows fluid exchange under the lens to remove debris and bring in oxygen. Patients with severe dry eye probably are not candidates for contact lens use. However, patients with moderate to mild dry eye may do well with contact lenses. Some soft lenses are marketed for dry eye patients; these lenses often have lower water content and/or better wettability. They may be made of material that is less prone to lens deposit formation.

Some patients may respond to placement of punctal plugs. Occasionally, the signs and symptoms of dry eye result from incomplete or infrequent blinking (fewer than 12 times per minute). The clinician may diagnose this condition by simply observing the patient during the examination. Some fitters feel that it is helpful to instruct the patient in how to blink.

Stein HA, Freeman MI, Stein RM. CLAO Residents Contact Lens Curriculum Manual. New York: CLAO; 1996. Suchecki JK, Donshik P, Ehlers WH. Contact lens complications. Ophthalmol Clin North Am. 2003;16(3):471–484.

Chapter Exercises

Questions

4.1. Following laser correction, a patient presents with blurred vision. The best spectacle-corrected visual acuity is 20/50. All of the following will be useful in defining the source of the blurred vision except

a.rigid contact lens overrefraction

b.potential acuity measurement

c.soft contact lens overrefraction

d.pinhole acuity measurement

Show Answer

4.2. A patient with keratoconus is unable to see adequately with spectacles or soft contact lenses. Standard RGP lenses allow adequate vision, but the discomfort is intolerable. An acceptable alternative in this situation would be any of the following except

a.piggyback soft and rigid contact lenses

b.corneal transplantation

c.specialty RGP contact lenses for keratoconus

d.hybrid contact lenses

e.scleral contact lenses