World Glaucoma Congress Melbourne 2019

World Glaucoma Congress Melbourne 2019

Dr Philip Rothschild presents TEI research at the World Glaucoma Congress in Melbourne, 27-30 March 2019

Recent University of Tasmanian graduate, Dr Philip Rothschild presented a poster titled ‘Factors influencing the success and failure of iStent and iStent inject, when combined with cataract surgery’ at the World Glaucoma Congress in Melbourne, 27-30 March 2019. The research was led by Dr Tze’Yo Toh in collaboration with Dr Philip Rothschild, Dr Joobin Hooshmand, Dr Penny Allen and Dr Brendan Vote.

The study aim was to identify the pre-operative variables that may predict the success of trabecular micro-bypass stents combined with cataract surgery.

A case series of 245 eyes with mild to moderate primary open angle glaucoma (POAG) undergoing trabecular micro-bypass with iStent of iStent inject insertion combined with cataract surgery. Primary success was defined as an IOP of ≤ 18 with zero medications at 12 months.

245 eyes from 148 patients, aged 53-89 years were assessed. There were 145 eyes in the iStent and 100 eyes in iStent inject groups. All patients had a confirmed diagnosis of POAG. The mean pre-operative IOP was 18.9 (SD 5.2).

Of the 219 eyes followed-up at 12 months, 100  (45.7%) failed to achieve an IOP of ≤ 18 with zero medications at 12 months. iStent/iStent inject was not associated with underlying glaucoma severity when VCDR (p=0.91), PSD (p=0.31), and central corneal thickness (p=0.37) were used as surrogates. Pre-operative IOP (3 groups: ≤15 vs 16-20 vs >20) (p<0.01) and the number of pre-operative agents (≥ 2 pre-operative hypotensive agents) (p<0.01) were associated with treatment failure at 12 months.

Compared to the reference group of IOP ≤15 mmHg, a pre-operative IOP>20 mmHg had an adjusted relative risk of failure of 1.8 (95% CI 1.2, 2.6). The adjusted relative risk for ≥2 pre-operative hypotensive agents was 2.3 (95% CI 1.6, 3.2), compared to those eyes with zero or one pre-operative agent.

In conclusion, both trabecular micro-bypass stents were effective in achieving a post operative IOP of ≤ 18mmHg with zero topical hypotensive agents at 12 months in patients with a pre-operative IOP of ≤ 15 mmHg who were treated with less than 2 topical hypotensive agents.