Incidence and Factors Associated with Postoperative Intraocular Pressure Spike Following Micropulse Transscleral Laser Therapy

Précis: We investigated early IOP changes after MPTLT in glaucoma patients. Sixteen percent experienced transient IOP spikes at 1 hour. Alpha-2 adrenergic agonist use was associated with reduced IOP elevation and lower spike risk. Purpose: To assess the incidence and contributing factors of postoperative intraocular pressure (IOP) spike following micropulse transscleral laser therapy (MPTLT) Patients and Methods: This prospective observational study included 80 eyes from 66 glaucoma participants undergoing MPTLT. An IOP spike was defined as an increase of 5 mmHg or more at 1 hour post-laser compared to baseline. Demographic and clinical factors were assessed, and multivariable backward stepwise regression mixed-effect models were employed to identify significant associations. The main outcome measures were the change in IOP at 1 hour (1-hour IOP minus baseline IOP) and the occurrence of a 1-hour IOP spike. Results: The mean (standard deviation) IOP change was -0.16 (6.40) mmHg at 1 hour. Thirteen eyes (16%) met the criteria for the IOP spike, with the average change of 9.73 (5.57) mmHg. Among these, five eyes (6% of all eyes) had IOP rise of greater than 10 mmHg. All eyes with IOP spike had IOP return to baseline levels or lower at 18 hours. Preexisting use of alpha-2 adrenergic (AA) agonists (coefficient -4.31, 95% CI -7.61 to -1.01, P =0.01) and higher baseline IOP (coefficient -0.12, 95% CI -0.23 to -0.004, P =0.042) were associated with less IOP elevation. Preexisting use of AA agonists was identified as a protective factor for developing an IOP spike with odds ratio of 0.20 (95% CI 0.42 to 0.91, P =0.038). Conclusions: One sixth of the patients experienced a postoperative IOP spike. Participants with preexisting use of AA agonists tended to have a lower degree of IOP change and a lower IOP spike.