Colletotrichum truncatum species complex: Treatment considerations and review of the literature for an unusual pathogen causing fungal keratitis and endophthalmitis.

We present a case of Colletotrichum truncatum species complex fungal keratitis and endophthalmitis in an 87-year-old immunocompetent male in whom oral triazole antifungals were contraindicated. The patient had recently returned from 4 months in Jamaica with a one month history of progressively increasing pain and inflammation in his left eye. Corneal samples grew a filamentous fungus and internal transcribed spacer sequencing polymerase chain reaction confirmed the presence of C. truncatum species complex. Samples showed no microbial growth.

Intravenous immunoglobulin for antibody-mediated keratolimbal allograft rejection.

A 33-year-old woman with congenital aniridia presented with decreased vision in her right eye. Slit lamp examination revealed diffuse conjunctivalisation of the ocular surface with mild subepithelial fibrosis consistent with aniridic keratopathy secondary to limbal stem cell deficiency. She underwent limbal stem cell transplantation with cadaver donor tissue (keratolimbal allograft (KLAL) surgery) and received systemic immunosuppression. Despite optimal combination immunosuppressive therapy managed by a renal transplant specialist, 2 weeks after the KLAL, the patient developed intractable eye pain, conjunctival injection, dilation of the KLAL graft blood vessels and limbal haemorrhages. There were no epithelial defects noted. Donor-specific antibody testing was positive, and intravenous immunoglobulin therapy was initiated. There was immediate symptomatic and objective improvement. Fifteen months postoperatively, the patient's vision was 20/400 with a stable corneal epithelium and no evidence of inflammation.

Keratoconus and crosslinking: pharmacokinetic considerations.

INTRODUCTION: Keratoconus (KC) is an ectatic disorder characterized by the progressive thinning and scarring of central cornea as a consequence of structural and/or compositional anomalies, although the exact etiology is largely unknown. The resultant conical protrusion of the cornea causes significant irregular astigmatism, myopia and visual impairment. AREAS COVERED: This paper will review the biochemical factors involved in the multifactorial pathogenesis of KC and the possible emerging role of inflammation in this process. Additionally, the authors discuss the development of new corneal collagen crosslinking (CCL) protocols using hypoosmolar riboflavin or transepithelial approaches with respect to the associated toxicities at the cellular level. EXPERT OPINION: Long-term consequences of standard and new emerging CCL protocols are still being studied; hence, pharmacokinetic considerations and related potential toxicities are important to consider. CCL sequentially combined with other modalities, specifically intrastromal corneal ring segments and photorefractive keratectomy can optimize the visual rehabilitation of KC patients. As we come to further understand CCL and its pharmacokinetic effects, additional indications for CCL may be discovered especially for those patients who are not suitable candidates for keratoplasty. Randomized control trials evaluating the efficacy of CCL for applications beyond halting KC disease progression are warranted.