SLT not best for PEXG patients

Performing selective laser trabeculoplasty (SLT) in patients with pseudoexfoliative glaucoma (PEXG) may in fact cause a rise in intraocular pressure (IOP), according to results published in the October issue of BMC Ophthalmology.

Mauro Cellini of the Department of Surgery Science and Anaesthesiology, Ophthalmology Service, University of Bologna, Italy and colleagues evaluated changes in metalloproteinases (MMP-2) and tissue inhibitor of metalloproteinases (TIMP-2) in PEXG patients by assessing the concentrations in the aqueous humour of MMP-2 and TIMP-2 after phacoemulsification in PEXG with cataract patients (n=15) and after SLT in PEXG patients (n=15), and compared these levels with those of the control group (n=15).

Before SLT treatment, patients had a mean IOP of 25.8±1.9 mmHg. Following SLT treatment, IOP initially dropped but then rebounded to pre-treatment levels, necessitating trabeculectomy: at day 10, IOP was 18.1±1.4 mmHg; at 31.5±7.6 days, IOP was 25.4±1.6 mmHg. In these patients, MMP-2 and TIMP-2 were 58.52±9.66 µg/ml and 105.96±27.65 µg/ml, respectively. In PEXG with cataract patients, these levels were 57.77±9.25 µg/ml and 105.19±28.53 µg/ml, respectively. The ratio of MMP-2 to TIMP-2 was 1.87:0.64 in the PEXG group, 1.88:0.65 in the PEXG with cataract group and 1.11:0.44 in control subjects.

The researchers concluded that this increase in the MMP-2/TIMP-2 ratio may be associated with any IOP increase that occurs after SLT in PEXG patients.