Rifabutin corneal deposits localized to the deep stroma using anterior segment optical coherence tomography

Late capsular blockage syndrome: Clinical and anterior segment optical coherence tomography characteristics

BACKGROUND

Late capsular blockage syndrome (CBS) is a rare phenomenon which is found after cataract surgery. The mechanism, anterior segment optical coherence tomography (OCT) presentation, and clinical characteristics are not well studied.

METHODS

We studied patients who developed late CBS in Taipei Veterans General Hospital from 2012 to 2019. Age, sex, systemic disease, ocular disease, interval between cataract surgery and CBS, axial length, type of intraocular lens implanted, grading of posterior capsular opacity, refraction, visual acuity, and anterior segment OCT findings were documented. Patients are categorized into two groups according to anterior segment OCT findings. All patients underwent Nd:YAG laser capsulotomy and were prescribed a low-dose topical steroid for 7 days. Postcapsulotomy refraction and visual acuity were recorded. All the clinical data were compared in the two groups.

RESULTS

This study included 18 eyes with late CBS. Patients' median age was 80 (range, 54-92) years. The mean duration between cataract surgery and CBS diagnosis was 80.28 (range 15-136) months. According to anterior segment OCT findings, we subcategorized the patients into two groups: gravel appearance (n = 7) and milky (n = 11) appearance. After laser capsulotomy, mean visual acuity improved 0.18 ± 0.10 on the LogMAR. A significant myopic shift in refraction after laser capsulotomy was noted in the gravel appearance group compared to the milky appearance group ( p = 0.027). No patient developed complications or needed further treatment for CBS during the median follow-up of 14.5 months (range 1-84 months).

CONCLUSION

High-resolution anterior segment OCT is useful for analyzing patients with late CBS. Our study implies that the two types of CBS presentation indicate different causes of late CBS formation, as well as distinct clinical presentation and postlaser capsulotomy refractive outcome. In addition, YAG laser capsulotomy is a safe late CBS treatment modality.

Drug-induced corneal deposits: an up-to-date review

This review assesses different clinical aspects of the various known drug-induced corneal deposits, based on the corneal layer involved (epithelium, stroma and/or endothelium), and based on the drug class. The most well-known condition caused by drug deposits is vortex keratopathy, or corneal verticillata, which is a whorl-like opacity in the corneal epithelium. Vortex keratopathy is commonly caused by certain cationic amphiphilic drugs such as amiodarone, antimalarials, suramin, tamoxifen, chlorpromazine and non-steroidal anti-inflammatory drugs. These deposits usually occur once a certain dose of the drug is reached. Most cases present with mild to moderate symptoms with minimal visual impairment. Most of these deposits resolve automatically, after months to years of drug cessation. Notably, other drug classes can cause deposits in all three layers of the cornea. Chlorpromazine, gold, rifabutin, indomethacin and tyrosine kinase inhibitors can cause stromal deposits, with reduced visual acuity when the anterior stroma is involved. Chlorpromazine and rifabutin can also cause deposits in the endothelial layer of the cornea. Regardless of the type of corneal deposit, local therapies such as topical lubricants or corticosteroids may help improve symptoms. Drug cessation or modification can also be helpful but should be weighed against the systemic risks of the underlying disease.