to the editor: Pflipsen and colleagues provide an excellent review of the primary care approach to patients with eye pain. They include a useful algorithm to guide the diagnostic evaluation in Figure 2, but I would suggest a slight modification. The premature inclusion of fluorescein staining in the initial diagnostic step may hamper the differentiation of corneal abrasion from corneal ulcer, which has implications for subsequent management.
Most evaluation protocols for suspected corneal pathology include slit lamp examination,1 but this is not readily available in many community primary care settings. Careful inspection of the cornea with good lighting and the aid of an ophthalmoscope or otoscope before applying the fluorescein will often reveal the gray infiltrate that helps distinguish an ulcer from an abrasion. This finding supports urgent ophthalmology referral as opposed to a more conservative approach for a suspected abrasion. Once the fluorescein has been placed, the uptake patterns for an abrasion and an ulcer are often similar, and the inflammatory infiltrate is obscured by the dye. A prospective review of a large number of corneal ulcers indicates a positive correlation between severe ulcers with virulent organisms, such as pseudomonas, and ulcer size at presentation,2 suggesting that the most clinically important ulcers are more likely to be detectable by careful inspection at the initial visit.
Patients with eye pain and foreign body sensation often present initially to family physicians. Most of these patients have a self-limited abrasion that will resolve with conservative management. Appropriate care and efficient use of medical resources hinge on an accurate diagnosis. Careful initial inspection of the cornea for evidence of an ulcer before fluorescein application can facilitate clinical decision making in these cases.