24-hour intraocular pressure monitoring in glaucoma patients

PURPOSE: To investigate circadian intraocular pressure (IOP) patterns in pseudoexfoliation (PE) glaucoma, primary open angle glaucoma (POAG) and PE syndrome by utilizing Trigger Fish Contact Lens (TFCL), and to evaluate tolerability and ocular surface effects of TFCL. METHODS: Six eyes of 6 newly diagnosed patients with no medical therapy, 3 with PE glaucoma, 2 with POAG and 1 with PE, were fitted with TFCL for 24 hours IOP monitorisation. IOP curves were analyzed with cosinor and biphasic cosinor models. Acrophase and bathyphase times and amplitudes were compared between patient groups. By evaluating one day at three different time periods, morning (6:00-11:00), afternoon-evening (12:00- 23:00), and night (24:00- 5:00), lowest and highest IOP related mV eq values were compared between groups. IOP peaks were investigated and peaks exceeding one hour were accepted as "prolonged peaks". To assess the safety and tolerability of TFCL use, before and after the procedure, both eyes were tested for best corrected visual acuity (BCVA), central corneal thickness (CCT) and corneal biomechanical measurements with Ocular Response Analyser and underwent biomicroscopic examination, Conjunctival hyperemia was evaluated with ORA Redness Scale and corneal staining with Modified Oxford Scale (MOS). FINDINGS: Mean age of participants was 61.6±7.7, with 5 (83.3%) men and 1 (16.7%) woman. Nocturnal acrophase pattern was detected in 4 (80%) out of 5 glaucoma patients in total; 1 patient displayed low amplitude acrophase pattern. During sleep period at night, prolonged peaks were seen in all PE glaucoma patients. In POAG patients, prolonged peaks were less numerous and occurred during both day or night. No significant differences of CCT and ORA parameters and BCVA were found between TFCL fitted and other eyes of patients before and after fitting (P>0.05). While MOS and ORA scales were not significantly different between the patients' fitted and non-fitted eyes before TFCL fitting (P>0.05), both were significantly different after TFCL fitting (P= 0.003 and P=0.004, respectively). TFCL was removed 3 hours earlier than planned in one patient because of intolerance. CONCLUSIONS: With the aid of TFCL, evaluation of 24 hour IOP profile provides valuable information about IOP patterns of glaucoma patients outside office hours. Nocturnal acrophase and frequent prolonged peaks in PE glaucoma calls attention. TFCL use is safe method, well tolerated by patients, has no significant and permanent effects on corneal parameters and ocular surface. Key words: circadien, contact lens, intraocular pressure, primary open angle glaucoma, pseudexfoliation glaucoma, pseudoexfoliation syndrome