Purpose
Pneumatic Trabeculoplasty (PNT) is a novel technique that reduces intraocular pressure (IOP). To evaluate the efficacy and the safety of PNT in patients with ocular hypertension (OHT) or ocular primary open angle glaucoma (POAG). To analyse the ocular anatomical changes using ultrasound biomicroscopy (UBM).
Methods
23 eyes of 23 patients with OHT or POAG and IOP > 21 mmHg were enrolled in this prospective study with a follow-up of 6 months. At baseline and at 6 months patients underwent BCVA, biomicroscopy, daytime IOP curve, gonioscopy, visual field 24-2, optic nerve SD-OCT and UBM examination. One eye was included in this study while the fellow eye was used as intra-individual control. A single PNT treatment included a combination of a vacuum application for 60 seconds followed by a 5 minutes rest period and by another PNT application. All patients underwent a single PNT at day 0 (baseline), 7, 90 and 180. The degree of opening of the anterior chamber angle and the surface of the ciliary body were recorded. Patient was considered responder if IOP reduction > 15% baseline IOP.
Results
At baseline, median IOP was 26.1 ± 1.9 mmHg in the treated eye, and 22.2 ± 2.2 mmHg in the fellow eye. 19 eyes (82.6%) were responders to PNT on day 90 and 180. At 6 months mean IOP was 21.4 ± 3.2 mmHg (-4.7 mmHg) in the treated eye. At 6 months, for good responders, median IOP was finally of 20.6 ± 1,7 mmHg with a median IOP decrease of 5.5 mmHg. Eyes responders to PNT showed a significant reduction of ciliary body area (mean decrease of 7.4 ± 3.5%, p<0.0001) compared to the fellow eyes (0.7 ± 1.6%, p=0.09), whereas non responders to PNT didn’t shown statistically significant reduction of ciliary body area compared to fellow eyes (p=0.07).
Conclusions
Our experience showed a mean IOP reduction of 4.7 mmHg from the baseline after 180 days in the treated eye by PNT. UBM analysis seems to confirm a cyclo-suppression effect with a likely decline in production of aqueous humor by the ciliary body.