An international team of researchers have found that atropine drop instillation following trabeculectomy surgery for glaucoma may lead to a reduction in significance and duration of visual quality.
Give me some background on atropine and glaucoma.
Atropine is often prescribed to patients post-trabeculectomy surgery because of its cycloplegic properties, including ciliary muscle relaxation and tightening the lens zonules, leading to a posterior displacement of the iris-lens diaphragm and anterior chamber deepening thereby potentially reducing anterior chamber inflammation.
Conversely, it contains mydriatic properties that can cause visual side effects, unintended cardiovascular system side effects, as well as alter a patient’s mental state.
Talk about the study.
A prospective, double-blind randomized study enrolled 40 patients (18 men, 22 women) who received standard trabeculectomy surgery with mitomycin C.
Each patient was administered dexamethasone (1.3 mg/mL) and ofloxacin (3 mg/mL) drops QID post-surgery, and then randomly split into two groups (20 patients in each). The intervention group received 1 mg/mL atropine drops, TID for two days, as part of their post-op care; the second group did not receive any atropine following surgery.
Patients of both groups completed a pre-op and post-op (two and six weeks) visual quality questionnaire. (via)
What happened with the intervention group?
Two weeks post-surgery, there was a significant reduction (Z/P = 0.00453) in self-assessed overall visual acuity of patients in the atropine group compared to their pre-op assessments. The number of patients who reported moderate or poor visual acuity illustrated a marked increase of 50%, from 45% to 95%.
Patients in the atropine group also reported more frequent hazy vision, blurred vision, difficulty estimating distances or depth, light sensitivity, difficult focusing, and halo perceptions. Six weeks postoperatively, the group reported fewer visual issues but still complained of frequent starburst and blurred vision compared to preop.
By the end of the second post-op week, the percentage of patients reporting blurred vision in varying severity leaped from 20% to 80%, remaining high (60%) by the end of the sixth post-op week.
And the control group?
Patients’ reported visual acuity was similar to the atropine group (Z/P =0.18406) two weeks post-op. No differences were reported in patients’ overall assessments (Z/P = 0.07078) six weeks postoperatively.
Six-week postop reported assessments were more in line with pre-op assessments: the percentage of patients who reported blurred vision jumped from 30% to 55% at the end of the 2-week post-op almost fully corrected to 35% by the end of week 6 post-op. Similarly, the percentage of patients who reported blurred vision boosted from 40% to 65% at two weeks post-op, but scaled back to 40% by six weeks postop. (via)
Expert input.
The study authors concluded that atropine-treated patients had a greater and longer-lasting visual quality reduction compared to the non-atropine-treated patients.
They suggested that using lower concentrations of atropine may lead to more protective effects in the anterior chamber following trabeculectomy—all while keeping visual impairment side effects to a minimum.
Take home?
The authors suggested that, providing there is no underlying medical necessity, they would discourage the use of atropine as a standard form of therapy for trabeculectomy surgery.