Hyphal Growth Patterns and Recurrence of Fungal Keratitis after Lamellar Keratoplasty
Received 24 February 2007; received in revised form 31 July 2007; accepted 31 July 2007. published online 05 October 2007.
Purpose
To evaluate growth patterns of fungal pathogens in corneas and recurrence of fungal keratitis after lamellar keratoplasty (LK).
Design
Retrospective noncomparative study.
Participants
One hundred seventy-four patients (174 eyes) with fungal keratitis who underwent LK at Shandong Eye Institute from January 2000 through November 2006.
Methods
Medical records of each patient were retrospectively reviewed. Hyphal growth patterns in corneas were evaluated by histopathological examination. Fungal recurrence after LK was observed during the follow-up.
Main Outcome Measures
Pathogens, hyphal growth patterns, and postoperative fungal recurrence.
Results
The pathogens were Fusarium (85.1%), Aspergillus (6.3%), Alternaria (4.6%), Penicillium (2.3%), and Candida (1.7%). Most Fusarium hyphae (91.2%) lay parallel to the corneal stromal lamellae, whereas most Aspergillus (90.9%) grew vertically. Recurrence of fungal keratitis was found in 15 patients (8.6%) after LK, and the pathogens were F. oxysporum (33.3%), F. solani (26.7%), F. moniliforme (13.3%), Aspergillus flavus (13.3%), Aspergillus fumigatus (6.7%), and Aspergillus terreus (6.7%). In cases of fungal recurrence, the majority of hyphae (80%) grew vertically. There was a higher recurrence rate in patients with vertically growing hyphae (46.2%) than in those with horizontally growing hyphae (2%) (χ2 = 54.664, P<0.001), as well as in those with Aspergillus keratitis (36.4%) versus those with Fusarium keratitis (7.4%) (χ2 = 10.031, P = 0.002). Reproducibility of the fungal recurrence rate was moderate in the patients with different hyphal growth patterns (κ = 0.534) but poor in those with different fungal pathogens (κ = −0.044).
Conclusions
Hyphal growth patterns in corneas differ not only in the same fungal genus but also in the same species. The fungal recurrence rate after LK in patients with hyphae growing horizontally is much lower than that in those with hyphae growing vertically. Growth patterns of fungal pathogens may be an important factor for fungal recurrence after LK.
Available online: October 24, 2007.
1State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Qingdao, China.
2Medical College of Qingdao University, Qingdao, China.
Correspondence to Lixin Xie, MD, Shandong Eye Institute, 5 Yanerdao Road, Qingdao 266071, China.
Manuscript no. 2007-273.
Supported by the National Natural Science Foundation of China, Beijing, China (grant nos. 30630063, 30271394); Department of Science and Technology of Shandong Province, Jinan, China (grant no. 2004GG2202154); and Qingdao Municipal Science and Technology Bureau, Qingdao, China (grant no. 02KGYSH-01).
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