Contact lens-related microbial keratitis.

OBJECTIVE: To review the clinical and microbiological profile in patients with contact lens-related microbial keratitis (CLRMK). MATERIAL AND METHOD: Hospital records of 435 patients with a diagnosis of microbial keratitis seen at Ramathibodi Hospital from January 1998 to December 2002 were retrospectively reviewed. All patients with CLRMK were included in the present study. RESULTS: Of the 435 cases, 81 (18.6%) were related to contact lens use. The disposable or frequent replacement of lenses were the most common lens-wearing type. Thirty-four percent of patients did not practice proper contact lens care and 67% wore contact lenses overnight. Corneal cultures were performed in 58 of 81 cases (72%) and were positive in 42 of 58 cases (72%). Pseudomonas aeruginosa was the most common organism (59%), followed by Klebsiella pneumoniae (11%). Polymicrobial infection was found in 19 cases. Most of the patients responded to medical treatment that led to the healing of ulcers whereas four patients required therapeutic penetrating keratoplasty. Most, of the organisms were sensitive to antibiotics. After treatment, 43% of the patients have continued contact lenses-wearing. CONCLUSION: CLRMK remains an essential problem in Thailand. Soft contact lens wear and overnight wearing seem to be the most important risk factors. Although the treatment outcome with medical therapy is good, keratitits may result in loss of vision. Ophthalmologist should warn contact lens wearers of this potential problem and instruct them on how to care for their lenses.

Pythium corneal ulcer in Ramathibodi Hospital.

This is a retrospective study of corneal ulcers caused by Pythium insidiosum in Ramathibodi Hospital from 1988 to 1998. The clinical data was from the medical records of 10 patients, of which 8 had complete information. Mean age of the patients was 49.8 years old and seven were farmers. Initial visual acuity was mostly below finger counts. All manifested as fungal corneal ulcers, diagnosis of Pythium insidiosum was confirmed by histology. After failed medication, penetrating keratoplasty (PKP) was performed in order to remove the infected tissue. One patient had only anterior lamella keratectomy performed and was completely cured. Seven other patients had to have their eyes removed (evisceration or enucleation) to be cured. The study shows that Pythium corneal ulcer is rare but devastating. Patients with an agricultural occupation are most at risk. Antibiotics and antifungals could not control or cure this disease, so education for people at high risk is advocated.