Purpose:
To evaluate the efficacy of brimonidine tartrate ophthalmic solution 0.15% (Alphagan–P®, Allergan, Inc., Irvine, CA,) in patients with night vision difficulties following laser refractive surgery.
Methods:
Six patients with significant night vision complaints following refractive surgery were enrolled in this study after excluding other treatable causes of night vision difficulty such as residual refractive error and dry eye. Low contrast visual acuity (LCVA) over a range of contrasts (1.25% to 25%) and small letter contrast sensitivity (CS) were tested at photopic (100 cd/m2) and mesopic luminance levels (1 cd/m2), with and without a standard glare source. Testing was performed before and 1 hour after using Alphagan–P®, and was repeated after subjects used Alphagan–P® nightly for 1 month.
Results:
1 hour after using Alphagan–P® subjects demonstrated significant improvement in LCVA and CS (Table 1). After 1 month of treatment all 6 patients reported subjective improvement in their night vision with Alphagan–P® use, and there was a significant difference in performance at the mesopic LCVA at 1.25% (p=0.028), 2.5% (p=0.030), and 5% (p=0.042). One patient reported tachyphylaxis after 6 months.
Conclusions:
Alphagan–P® improves contrast sensitivity and acuity and decreases night vision difficulty in patients with significant complaints following refractive surgery.
Keywords: contrast sensitivity • refractive surgery