Loop Diuretic Linked to Angle-Closure Glaucoma in Pregnant Patient
Sulphonamide-containing drugs have been previously reported in the literature to be associated with bilateral angle-closure glaucoma, but a case published in the Journal of Glaucoma purports to be the first to reveal the association between furosemide use and this condition.
The patient, a 21-year-old African American female, presented in her 17th week of pregnancy complaining of blurred vision in both eyes. Upon removing her glasses, her vision would improve, however for the past 2 weeks her vision was constantly blurry. While her glycemic status was normal, her blood pressure (BP) had been moderately elevated (systolic BP ~150mmHg); medical history also included hypertension with chronic kidney disease, two prior failed pregnancies complicated by fluid overload, type 1 diabetes, hyperlipidemia, depression and non-proliferative background diabetic retinopathy with diabetic macular edema bilateral, and hyperopic astigmatism. Her medications included insulin, levothyroxine, diltiazem, labetolol, and furosemide (started at the 9th week of pregnancy).
Initial slit-lamp examination showed anterior chambers were shallow and gonioscopy revealed narrow grade 1 angles (Schaffer classification); intraocular pressures (IOP) were 24mmHg in the right eye and 25mmHg in the left eye. The patient returned three days later at which point IOPs had increased to 36mmHg in the right eye and 33mmHg in the left eye. To relieve occult pupillary block, yttrium aluminum garnet laser peripheral iridotomies was performed which decreased the IOP for about 10 days. Shortly thereafter, atropine 1% was dosed in both eyes but that failed to change the IOP or gonioscopic appearance.
Two weeks after she first presented, the patient had developed IOPs in the low 40s. As in prior exams, diffuse retinal edema was noted; gonioscopy revealed the angles were mostly closed by apposition. Following punctal plug insertions (to minimize systemic absorption), the patient was started on brimonidine 0.1% in both eyes twice daily. She was admitted to the obstetrics ward where she was then started on prednisone 60mg daily.
Three days after oral steroids were started, the patient's IOP dropped to 22mmHg in the right eye and 20mmHg in the left eye; after one week on steroid therapy, anterior chambers appeared deeper and gonioscopy confirmed that the angles were opening. With this improvement, prednisone dose was reduced to 40mg daily while topical brimonidine was maintained.