Therapeutic penetrating keratoplasty in severe fungal keratitis using cryopreserved donor corneas

Abstract

Aims: To investigate whether cryopreserved donor cornea could be used for therapeutic penetrating keratoplasty (PKP) to eradicate the infection, obviate complications, and preserve anatomical integrity in severe fungal keratitis. Methods: In this retrospective, consecutive case series, 45 eyes of 45 patients with severe fungal keratitis, which exhibited anterior chamber collapse, corneal perforation, and/or large suppurative corneal infiltrate, received therapeutic PKP after removal of the infected corneal tissue, irrigation of the anterior chamber by 0.2% fluconazole solution, iris dissection of fibrinoid membrane, and iridectomy and therapeutic PKP using corneas cryopreserved at −20°C. Results: Among 45 eyes, 39 eyes (86.7%) were successfully eradicated the fungal infection without recurrence and maintained their anatomical integrity without any complication. Four of 45 eyes (8.9%) showed postoperative rise of intraocular pressure, of which three were controlled with subsequent antiglaucoma surgeries, whereas one eye needed additional antiglaucoma medications. Two of 45 eyes (4.4%) were enucleated because of uncontrollable fungal infection and secondary retinal detachment, respectively. 23 eyes received subsequent optical PKP and, among them, 21 maintained clear corneal grafts and two suffered from graft failure due to allograft rejections. Conclusion: Cryopreserved donor corneas are effective substitutes in therapeutic PKP to control severe fungal corneal infection and preserve the global integrity, and may offer additional advantages over conventional PKP in reducing allograft rejection, eradicating fungal infection during the postoperative period, and improving the success of optical PKP for visual rehabilitation.

Use of PCR Targeting of Internal Transcribed Spacer Regions and Single-Stranded Conformation Polymorphism Analysis of Sequence Variation in Different Regions of rRNA Genes in Fungi for Rapid Diagnosis of Mycotic Keratitis

“…Species of the genus Curvularia are frequently isolated, while an Epidermophyton sp. has rarely been reported as a cause of mycotic keratitis (19,26). The PCR product sequencing studies resulted in the identification of these isolates as the Colletotrichum state of G. cingulata (100% similarity), C. inaequalis (99% similarity), and E. floccosum (98% similarity).…”

Eye preservation tectonic graft using glycerol-preserved donor cornea

“…Glycerol is a dehydrating agent with antimicrobial and antiprotease properties. However, glycerol will not preserve endothelial viability, a condition needed for optical PKP; cryopreservation 12,13 and 34 1C organ culture 14 will allow long-term storage of viable corneal tissue. Cryopreservation and organ culture, because of their technical complexity and cost, have limited application in the areas, which lack fresh donor corneas.…”

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“…[10][11][12] Nevertheless, this surgery has disadvantages including a high incidence of graft infection and failure. 6,[23][24][25][26] The graft survival rate for therapeutic corneal transplant is related with the type of infective agent, the severity of inflammation, surgical timing, donor tissue quality, graft size, preand postoperative medical treatment, and perforation existence. 27 Unless the cornea is perforated, therapeutic corneal transplant is recommended to be performed 7 to 10 days after initiating antifungal drugs.…”

“…However, if there is a corneal perforation, corneal transplant should be performed as soon as possible. 26 In cases with corneal perforation or excessive fungal disease, we performed a corneal transplant as soon as possible. The mean time in our cases between the first visit and surgery was 15.47 days.…”