Paradoxical response to carbonic anhydrase inhibitors in patients with intraretinal cystoid spaces

ABSTRACT

Background: Intraretinal cystoid spaces (IRCS) are fluid-filled spaces seen in some retinal dystrophies and often treated with carbonic anhydrase inhibitors. The purpose of this study is to report an unexpected bilateral improvement in the IRCS after discontinuation of therapy.

Material and Methods: We identified from our records 23 patients with retinal dystrophy and IRCS who had been treated with topical and/or oral carbonic anhydrase inhibitors. All subjects had regular follow-up with OCT and previous genetic testing.

Results: We identified four (17%) patients who experienced a bilateral and symmetrical paradoxical improvement in IRCS size and visual acuity after discontinuation of carbonic anhydrase inhibitors. Two were mutations in RS1, one in CLN3 and another in NR2E3. All patients were followed for at least three years (range 39–63 months). None had systemic abnormalities.

Conclusions: Patients with IRCS may exhibit a paradoxical response after discontinuation of carbonic anhydrase inhibitors. Although the pathophysiology of these phenomena is unclear, stopping treatment may be an option in patients who cease to improve or get worse on treatment.

KEYWORDS:

• Paradoxical response
• retinal dystrophy
• carbonic anhydrase inhibitors
• retinoschisis
• macular edema

Conflict of interests

No conflicting relationship exists for any author.

Additional information

Funding

This work was submitted in part by The Foerderer Fund (AVL) and the Robison D. Harley, MD Endowed Chair in Pediatric Ophthalmology and Ocular Genetics (AVL);Robison D. Harley, MD Endowed Chair in Pediatric Ophthalmology and Ocular Genetics [Not applicable];Foerderer Fund (AVL) [Not applicable];