Eyeworld

EW INTERNATIONAL 66 February 2019 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer of different IOP lowering interven- tions on CLS parameters and their relationship with GAT-measured IOP reduction." Study design Thirty centers from 16 countries were involved in this prospective investigation that tested the hy- pothesis that the contact lens sensor device can objectively measure treatment effects in glaucoma patients undergoing different types of IOP-lowering interventions. The study set out to determine which type of intervention had the stron- gest effect on 24-hour ocular dimen- sional patterns related to IOP. One hundred and eighty-two eyes of 182 patients were included in the study in which the 24-hour ocular dimensional profile was recorded in one eye/patient via CLS both before and after IOP lowering interventions. The interventions im- plemented included topical pressure Researchers think a contact lens sensor has potential in the assessment of treatment efficacy of IOP lowering interventions D aytime intraocular pres- sure (IOP) measurements have long been questioned for their accuracy in reflecting the actual highs and lows of a glaucoma patient's IOP. Patients with well-controlled daytime pressures, as measured at the doctor's office, will often develop signs of glaucoma pro- gression with visual field defects. IOP is a modifiable glaucoma risk factor known to fluctuate during the course of the day, and therefore, as- sessing the extent of this fluctuation could be instrumental in helping to guide clinical management in indi- viduals with glaucoma. According to an e-poster presented at the 36th Congress of the European Society of Cataract and Refractive Surgeons (ESCRS) by Carlo Cutolo, MD, Genova, Italy, and co-authors, many glaucoma patients progress and lose valuable eye sight, even those with apparent- ly low IOP measurements. He thinks that the 24-hour variability in IOP may explain optic nerve vulnerabil- ity better than IOP measured during office hours. "Many glaucoma patients experience visual field deterioration despite intraocular pressure mea- surements within normal limits during office hours," Dr. Cutolo said. "Parameters derived from a contact lens based system [CLS, Sensimed Triggerfish, Lausanne, Switzer- land] have recently been shown to correlate better with visual field pro- gression than office hour Goldmann applanation tonometry (GAT). 1,2 In this study, we investigated the effect lowering medications in 60 eyes, laser trabeculoplasty in 69 eyes, and incisional surgery in 53 eyes. A set of 115 different CLS parameters were investigated from the 24-hour recordings. Dr. Cutolo compared before versus after values for each parameter. The average time between measurements was 66±53 days. In addition, linear regression was performed using the percentage change of each CLS parameter as the outcome variable and the type of IOP lowering procedure as the predictor after adjusting for age and race. Finally, the study investigated the relationship between changes in CLS parameters and GAT IOP with Pearson's correlations. The Benjami- ni-Hochberg approach was used to adjust for multiple tests. Open angle glaucoma patients, ocular hypertensives, and glauco- ma suspects underwent a 24-hour CLS and were included in the study provided their CLS readings were sufficient and reliable. Patients with incomplete or insufficient CLS recordings were excluded from the study. Study outcomes All three interventions were effec- tive in reducing IOP in the study participants, to varying degrees. The mean IOP measured in the inci- sional surgery patient group prior to the intervention was 21.4 mm Hg, which was reduced by a mean –6.8 mm Hg (95% CI –9.3 to –4.2) to a mean 14.7 mm Hg after the intervention. In the trabeculoplasty group, IOP went from a mean 17.2 mm Hg before to 14.6 mm Hg after the intervention, reflecting a reduc- tion of –2.7 mm Hg (95% CI –3.6 to –1.7). IOP in the group treated with topical medications was 18.1 mm Hg before and 17.1 mm Hg after drug administration, which was a change in pressure of –0.97 mm Hg (95% CI –2.1 to 0.18). The linear regression analysis revealed that for 23 CLS parameters, incisional surgery was significantly more effective than the other two interventions. Surgery was most predictive for the greatest percentage of change in CLS signals. For one CLS parameter, laser trabeculoplasty was shown to be significantly more effective than topical medications. 24-hour ocular dimensional profile sheds light on 'unexplained' glaucoma progression Dr. Cutolo used a contact lens sensor to record IOP for a 24-hour period and was able to link specific pressure-related parameters with visual field progression. Source: Carlo Cutolo, MD continued on page 68 Presentation spotlight

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