Purpose: To determine the prevalence and risk factors for glaucoma filtering bleb dysesthesia (discomfort).
Methods: A prospective cross-sectional observational study of consecutive patients with unilateral glaucoma filtering blebs from trabeculectomy was conducted. A self-report questionnaire was administered, which asked about the frequency and severity of the following symptoms: ocular pain, discomfort, burning, foreign body sensation, and tearing. The following variables were recorded by the investigators: age, race, sex, type and date of glaucoma surgery, antifibrotic agent used, intraocular pressure, location, thickness, and size of bleb, percent coverage of the bleb by the eyelid, angle that the bleb made to the cornea, and the presence of epithelial defects or dellen. Dysesthesia scores between the affected eye and control eye were compared using the paired Student t test. Risk factors for dysesthesia were evaluated using analysis of variance or Pearson correlation coefficient.
Results: A total of 97 patients were enrolled in the study. The mean total dysesthesia score (+/-SD, range) in the affected eye was 11.1 (+/-9.4, 0 to 42) and in the unaffected eye 3.4 (+/-4.9, 0 to 25, P =.001). Factors that predisposed to dysesthesia included younger age (P =.005), superonasal location of bleb (P =.036), presence of bubbles (P =.028), and poor lid coverage (P =.013). The steeper the angle of the bleb to the cornea, which was an indirect measure of the height of the bleb, the more likely a patient was to have bubbles (P =.001).
Conclusion: Eyes with glaucoma filtering blebs experience more dysesthesia than eyes without filtering blebs. Young age, superonasal bleb location, poor lid coverage, and bubble formation are all associated with glaucoma filtering bleb dysesthesia.