New Molteno implant yields similar results to older double-plate design

This retrospective study found that the 175mm² Molteno3 implant provided comparable success at controlling IOP in the intermediate term in non-neovascular glaucoma patients to the gold-standard double-plate Molteno implant.

This study is important because it illustrates that the smaller Molteno3 implant is as efficacious as the larger double-plate Molteno implant. In addition to using a familiar surgical technique similar to that used with the Baerveldt implant and Ahmed valve, the Molteno3 uses single-quadrant dissection, which may allow for a faster, easier and less traumatic procedure.

The authors compared results at three years of follow-up of the first 87 eyes at one hospital to receive the 175mm² Molteno3 implant with a control group of 115 eyes treated with the double-plate implant.

They found no statistical differences in IOP control, BCVA or hypotensive medication use at any time point between the groups. The probability of IOP control at three years was 0.79 in both groups.

There were significantly more cases of flat anterior chamber requiring reformation in the double-plate group compared to the Molteno3 group (5 percent vs. 0 percent; P = 0.03). However, the frequency of hypotony, choroidal detachment, shallow anterior chamber and diplopia were similar. Additionally, eyes receiving a Molteno3 implant without a Vicryl tie had a significantly higher likelihood of hypotony, and significantly more eyes with the Molteno3 were implanted without a Vicryl tie.

The Molteno3 results were achieved with a much smaller drainage area. The authors postulate that this implant design achieves a more favorable balance between the fibroproliferative and fibrodegenerative responses that occur in bleb capsules after implant insertion, resulting in a thinner, more permeable bleb.