An experimental model of mycobacterial infection under corneal flaps.

In order to develop a new experimental animal model of infection with Mycobacterium chelonae in keratomileusis, we conducted a double-blind prospective study on 24 adult male New Zealand rabbits. One eye of each rabbit was submitted to automatic lamellar keratotomy with the automatic corneal shaper under general anesthesia. Eyes were immunosuppressed by a single local injection of methyl prednisolone. Twelve animals were inoculated into the keratomileusis interface with 1 microl of 10(6) heat-inactivated bacteria (heat-inactivated inoculum controls) and 12 with 1 microl of 10(6) live bacteria. Trimethoprim drops (0.1%, w/v) were used as prophylaxis for the surgical procedure every 4 h (50 microl, qid). Animals were examined by 2 observers under a slit lamp on the 1st, 3rd, 5th, 7th, 11th, 16th, and 23rd postoperative days. Slit lamp photographs were taken to document clinical signs. Animals were sacrificed when corneal disease was detected and corneal samples were taken for microbiological analysis. Eleven of 12 experimental rabbits developed corneal disease, and M. chelonae could be isolated from nine rabbits. Eleven of the 12 controls receiving a heat-inactivated inoculum did not develop corneal disease. M. chelonae was not isolated from any of the control rabbits receiving a heat-inactivated inoculum, or from the healthy cornea of control rabbits. Corneal infection by M. chelonae was successfully induced in rabbits submitted to keratomileusis. To our knowledge, this is the first animal model of M. chelonae infection following corneal flaps for refractive surgery to be described in the literature and can be used for the analysis of therapeutic responses.

An experimental model of mycobacterial infection under corneal flaps

In order to develop a new experimental animal model of infection with Mycobacterium chelonae in keratomileusis, we conducted a double-blind prospective study on 24 adult male New Zealand rabbits. One eye of each rabbit was submitted to automatic lamellar keratotomy with the automatic corneal shaper under general anesthesia. Eyes were immunosuppressed by a single local injection of methyl prednisolone. Twelve animals were inoculated into the keratomileusis interface with 1 æl of 10(6) heat-inactivated bacteria (heat-inactivated inoculum controls) and 12 with 1 æl of 10(6) live bacteria. Trimethoprim drops (0.1 percent, w/v) were used as prophylaxis for the surgical procedure every 4 h (50 æl, qid). Animals were examined by 2 observers under a slit lamp on the 1st, 3rd, 5th, 7th, 11th, 16th, and 23rd postoperative days. Slit lamp photographs were taken to document clinical signs. Animals were sacrificed when corneal disease was detected and corneal samples were taken for microbiological analysis. Eleven of 12 experimental rabbits developed corneal disease, and M. chelonae could be isolated from nine rabbits. Eleven of the 12 controls receiving a heat-inactivated inoculum did not develop corneal disease. M. chelonae was not isolated from any of the control rabbits receiving a heat-inactivated inoculum, or from the healthy cornea of control rabbits. Corneal infection by M. chelonae was successfully induced in rabbits submitted to keratomileusis. To our knowledge, this is the first animal model of M. chelonae infection following corneal flaps for refractive surgery to be described in the literature and can be used for the analysis of therapeutic responses.

Findings in the anterior segment on ultrasound biomicroscopy in Maroteaux-Lamy syndrome.

PURPOSE: Maroteaux-Lamy syndrome is one of the mucopolysaccharidoses caused by enzyme deficiency (arylsulfatase B) that leads to incomplete degradation and storage of dermatan sulfate. We report a case of mucopolysaccharidosis type VI (MPS VI; Maroteaux-Lamy syndrome) with corneal involvement and introduce ultrasound biomicroscopy (UBM) as an examination with which to follow disease progression in relation to deposition in cornea, angle, and iris. METHODS: We describe a 11-year-old boy with a clinical and laboratorial diagnosis of MPS VI who developed increasing bilateral corneal opacification and decreased visual acuity. He underwent two seriate UBM (50-MHz transducer) evaluations. RESULTS: UBM examination showed diffuse and homogeneous stromal hyper-reflective deposit in both eyes and an increase in peripheral corneal thickness throughout time. CONCLUSION: High-frequency ultrasound documentation of corneal deposit and anterior segment involvement in a patient with Maroteaux-Lamy syndrome is unique, and follow-up revealed thickening of the corneal periphery, which may be related to the progression of the disease (continuous mucopolysaccharide deposits in corneal stroma). UBM was used to locate and document the deposit, as well as to accompany the deposit's evolution, characterizing corneal changes and angle structure involvement.