Intraocular Pressure Fluctuations Recorded by a Telemetric Sensor After Nonpenetrating Glaucoma Surgery in Primary Open-Angle Glaucoma.

Objective: To investigate short- and long-term intraocular pressure (IOP) fluctuations in patients with primary open-angle glaucoma (POAG) after successful nonpenetrating glaucoma surgery (NPGS).

Design: Prospective, open-label, multicenter interventional study.

Subjects: A total of 20 patients with POAG who underwent NPGS combined with permanent implantation of a suprachoroidal telemetric IOP sensor (EyeMate-SC, Implandata Ophthalmic Products GmbH, Hanover, Germany). The mean age of the cohort was 66.9 ± 10.6 years. Half were male, and half were female.

Methods: Telemetric IOP measurements were obtained over a 3-year period, excluding the first 180 postoperative days and those during which ocular glaucoma medications were applied. One day was divided into eight time-of-day periods (TODs). The median absolute difference (MAD) in IOP between day χ and day χ + 7, 30, 90, 180, and 360 was calculated for each TOD and each eye, in which sequential IOP measurements were accordingly available.

Main outcome: IOP fluctuations.

Results: The mean follow-up duration was 952.8 ± 276.6 days. For analysis, a total of 139,512 mean IOP values were paired. Overall, diurnal IOP decreased by 20.7%, from 11.1 ± 5.0 mmHg in the "early morning" to 8.8 ± 3.2 mmHg in the "late evening", followed by a nocturnal IOP increase of 13.6% to 10.0 ± 3.8 mmHg in the "late night". Independently of the TOD, fluctuations were smallest during the 7-day interval and largest during the 360-day interval. The awake period, lasting from early morning to early evening, displayed increasing MADs with growing time interval, resulting in moderate IOP fluctuations in the short term (1.5 mmHg < MAD < 2.0 mmHg) and large fluctuations in the long term (MAD > 2.0 mmHg). The late-night TOD displayed the lowest fluctuation amplitude.

Conclusions: Nychthemeral IOP fluctuations persist in eyes with an average IOP of 10 mmHg following successful NPGS. Short-term IOP fluctuations were moderate, whereas long-term fluctuations were large. Irregular IOP measurements are insufficient to assess IOP fluctuation and thus to determine optimal glaucoma management. The implementation of safe and accurate telemetric sensors has the potential to enhance glaucoma management.