Sandwich Infectious Keratitis ("SIK") - A New Clinical Entity Following Lamellar Keratoplasty (DLEK, DSAEK, DALK, ALK)

Abstract

Purpose: : To report sandwich infectious keratitis ("SIK") a new clinical entity of interface infections after deep lamellar endothelial keratoplasty (DLEK), Descemet stripping automated endothelial keratoplasty (DSAEK), pre-Descemetic deep anterior lamellar keratoplasty (DALK), and anterior lamellar keratoplasty (ALK).

Methods: : Four cases of SIK were identified and retrospectively reviewed.

Results: : Case 1: 74-yoF underwent DLEK OU for pseudophakic bullous keratopathy. Left SIK required a therapeutic keratoplasty (TKP). Cornea was evaluated by immunohistochemistry (IH), light, scanning and transmission electron microscopy (SEM, TEM). SIK developed 6 wks after DLEK with 4+ (scale 1-4+) interface infiltrates. Corneal and AC fluid cultures grew Candida (Torulopsis) glabrata. IH revealed endothelial herpes simplex. Conjunctival culture grew coagulase-negative Staphylococcus species. SEM and TEM revealed bacteria, fungi, and inflammatory cells in the corneal sandwich. Patient received antibacterial, antifungal, and antiviral agents. Case 2: 77-yoM developed SIK with hypopyon 3 wks after right DSAEK. Anterior chamber (AC) tap and antibiotic injection were performed. Cultures confirmed Candida glabrata. Treatment included AC injection of voriconazole 50 µm/0.1cc, topical natamycin and oral posaconazole. Later natamycin was replaced with topical voriconazole, and Prednisolone acetate 1% with cyclosporine A 2% drops. SIK resolved on medical treatment. Case 3: SIK developed 6 days after pre-Descemetic DALK for keratoconus. Smear, culture and PCR were positive for Streptococcus pneumoniae. Interface lavage, moxifloxacin, tobramycin, fortified vancomycin and lamellar keratoplasty were required. Streptococcal crystalline keratitis 17 mths later was cured with medical therapy and TKP. Case 4: 34-yoF developed SIK 19 mths post 2-stage ALK for lattice dystrophy. Culture was positive for 2 strains of coagulase-negative Staphylococcus. Moxifloxacin, fortified vancomycin and tobramycin resulted in resolution of infiltrate.

Conclusions: : SIK is a new clinical entity. Unlike a corneal ulcer, SIK has atypical symptoms and signs and is challenging to treat surgically and medically. Clinicians should be aware of this new entity.

Keywords: cornea: clinical science • keratitis • cornea: stroma and keratocytes