Abstract
Purpose:
To evaluate the changes in the cornea attributed to selective trabectuloplasty in patients with open angle or normotensive glaucoma.
Methods:
A prospective observational study was conducted on 46 patients undergoing selective trabeculoplasty (SLT) either on one or both eyes, with a total of 68 eyes. All patients with prior corneal disease or recent cataract surgery (<1 year), as well as contact lens wearers were excluded from the study. Corneal specular microscopy photographs were taken prior to SLT and at the 4 to 6 weeks follow-up. All photographs were screened for quality and were only included in the study if the number of cells analyzed exceeded 100 cells. Intraocular pressure (IOP) was measured before and after the pocedure as well as at the 4-6 weeks follow-up. SLT was done using a mean of 50 hits on 180 or 360 degrees of trabecular meshwork, for a mean total energy of 48 mJ. A mixed model of repeated measurements allowed the analysis of the effect of the SLT (SLT-1 being on the first eye undergoing laser in all patients and SLT-2 being on the second eye where applicable), the time (before and after) and their interaction on the 5 variables of interest (cellular density, mean area, polymegetism, pleomorphism and pachymetry). IOP, age, gender, SLT measured energy, SLT calculated energy, visual acuity and number of cells variables were used as controls when necessary.
Results:
There is no significant effect of SLT on the cellular density of the cornea at the follow-up. Taking into account the number of cells variable, the follow-up density was found to be significantly higher after SLT-2 (p = 0,0346) . Moreover, there was a significantly higher density after SLT-2, compared to SLT-1 (p = 0.0465). There is no significant effect of SLT on the mean area, polymegetism and pleomorphism. As for the pachymetry, there is a tendency of it being increased after SLT-2, compared to the SLT-1 (p = 0,0529) and the difference is statistically significant in males when taking into account the gender covariable (p = 0,0470).
Conclusions:
This study suggests that SLT is safe for the corneal endothelium as it does not significantly alter its density.
Keywords: 578 laser •
481 cornea: endothelium