Prospective, Randomised Controlled Trial of Cataract Surgery versus combined Cataract Surgery with insertion of iStent Inject.

PURPOSE: To evaluate the efficacy and safety of combined cataract surgery with insertion of an ab interno trabecular microbypass device (iStent Inject, Glaukos Corporation) compared to cataract surgery alone in patients with mild-to-moderate glaucoma.

DESIGN: Prospective, randomized, assessor-masked controlled trial at a single centre.

PARTICIPANTS: Eyes with visually-significant cataract and mild-to-moderate glaucoma with preoperative intraocular pressure (IOP) of 12 - 30 mmHg on 0 to 3 ocular hypotensive medications.

METHODS: Participants eyes were randomised (2017-2020) 1:1 to combined cataract surgery with iStent Inject (treatment group, n= 56) or cataract surgery alone (control group, n=48), and followed up for two years.

MAIN OUTCOME MEASURES: The co-primary effectiveness endpoints were the number of ocular hypotensive medications and IOP at 24-months post-surgery. The secondary effectiveness endpoints were ocular comfort as measured by the Ocular Surface Disease Index (OSDI) and vision-related quality of life as measured by the Glaucoma Activity Limitation Questionnaire (GAL-9) at 24-months. Safety measures included postoperative visual acuity, any unplanned return to the operating theatre, adverse events, and complications.

RESULTS: Participants (67.3% male) were aged 53-85 years and treatment groups were similar in terms of mean medicated IOP (treatment group 17.7 mmHg ± 4.0; control group 17.1 mmHg ± 3.1), and number of ocular hypotensive medications (treatment group 1.69 ± 1.05; control group 1.80 ± 1.22) at baseline. At 24 months, the number of ocular hypotensive medications were 0.7 ± 0.9 in the treatment groups compared to 1.5 ± 1.9 in the control group, with an adjusted difference of 0.6 fewer medications per eye in the treatment group (95% CI 0.2 to 1.1, p=0.008). 57% of eyes in the treatment group were on no glaucoma medications compared to 36% in the control group. There was no significant difference in IOP between the two groups beyond the 4-weeks. There were no differences in patient-reported outcomes between the two groups. The visual outcomes and safety profiles were similar between the two groups.

CONCLUSIONS: Combined cataract surgery with iStent Inject achieved a clinically- and statistically-significantly greater reduction in ocular hypotensive medication usage at 24-months compared to cataract surgery alone, with no significant difference in IOP.