Interventional procedure overview of trabeculectomy with a biodegradable collagen matrix implant for glaucoma

Safety summary

Hypotony (IOP <5mm Hg)

In the meta-analysis of 11 studies, comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC, pooled analysis of 10 studies reported a statistically significantly higher incidence of hypotony in the MMC group (collagen implant 25/183 versus MMC 40/193, RR 0.64 [95% CI 0.42 to 0.98], p=0.04) (Song 2019).

In a Cochrane review, pooled analysis of 6 studies (including 233 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for hypotony (collagen implant 19/112 versus trabeculectomy plus MMC 27/121, RR 0.75 [95% CI 0.47 to 1.19], p=0.22) (Wang 2015).

Hypotony maculopathy

In the meta-analysis of 11 studies, 1 study reported that the rate of hypotony maculopathy was similar between the groups (collagen implant 4/20 versus MMC 8/20, RR 0.50 [95% CI 0.18 to 1.40], p=0.19) (Song 2019).

Surgical revision

In the Cochrane review, pooled analysis of 4 studies (including 150 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups in the rates of surgical revision within 3 months (collagen implant 7/75 versus MMC 3/75, RR 1.7 [95% CI 0.38 to 7.63], p=0.49) (Wang 2015).

Endophthalmitis or blebitis

In the meta-analysis of 11 studies, pooled analysis of 3 studies reported that the rate of blebitis was similar between the groups (collagen implant 3/109 versus MMC 5/118, pooled RR 0.73 [95% CI 0.21 to 2.47], p=0.61) (Song 2019).

In the Cochrane review, pooled analysis of 3 studies (including 164 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for endophthalmitis or blebitis (collagen implant 2/78 versus MMC 1/86, RR 1.57 [95% CI 0.25 to 9.70], p=0.63) (Wang 2015).

Bleb leakage

In the meta-analysis of 11 studies, pooled analysis of 8 studies reported that the rate of bleb leakage was similar between the groups (collagen implant 12/135 versus MMC 15/137, RR 0.81 [95% CI 0.41 to 1.63], p=0.56) (Song 2019).

In the Cochrane review, pooled analysis of 4 studies (including 129 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for bleb leakage (collagen implant 7/64 versus MMC 9/65, RR 0.85 [95% CI 0.33 to 2.2], p=0.73) (Wang 2015).

Hyphaema

In the meta-analysis of 11 studies, pooled analysis of 9 studies reported that the rate of hyphaema was similar between the groups (collagen implant 18/165 versus MMC 11/167 RR 1.65 [95% CI 0.83 to 3.29], p=0.16) (Song 2019).

In the Cochrane review, pooled analysis of 6 studies (including 229 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for hyphaema (collagen implant 16/114 versus MMC 9/115, RR 1.46 [95% CI 0.51 to 4.19], p=0.48) (Wang 2015).

Encapsulated bleb

In the meta-analysis of 11 studies, pooled analysis of 2 studies reported that the rate of encapsulated bleb was similar between the groups (collagen implant 3/38 versus MMC 2/46, RR 1.68 [95% CI 0.30 to 9.43], p=0.56) (Song 2019).

Flat avascular bleb

Flat non-filtering blebs were reported in 10% (2/20) of eyes in the shunt device group and 15% (3/20) of eyes in the collagen implant group in the RCT of 33 patients (40 eyes) at 6 months follow up (Bhatkoti 2021).

Choroidal detachment

In the meta-analysis of 11 studies, pooled analysis of 5 studies reported that the rate of choroidal detachment was similar between the groups (collagen implant 9/95 versus MMC 10/97, RR 1.10 [95% CI 0.56 to 2.15], p=0.78) (Song 2019).

In the Cochrane review, pooled analysis of 4 studies (including 129 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for choroidal detachment (collagen implant 7/64 versus MMC 9/65, RR 0.83 [95% CI 0.33 to 2.09], p=0.7) (Wang 2015).

Shallow anterior chamber

In the meta-analysis of 11 studies, pooled analysis of 9 studies reported that the rate of shallow anterior chamber was similar between the groups (collagen implant 17/162 versus MMC 20/171, RR 0.88 [95% CI 0.50 to 1.53], p=0.65) (Song 2019).

In the Cochrane review, pooled analysis of 5 studies (including 213 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for shallow anterior chamber (collagen implant 7/102 versus MMC 9/111, RR 0.79 [95% CI 0.32 to 1.93], p=0.6) (Wang 2015).

Anterior chamber reaction

In the meta-analysis of 11 studies, pooled analysis of 5 studies reported that the rate of anterior chamber reaction was similar between the groups (collagen implant 18/100 versus MMC 17/102, RR 1.09 [95% CI 0.61 to 1.93], p=0.78) (Song 2019).

In the Cochrane review, pooled analysis of 2 studies (including 99 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for anterior chamber reaction (collagen implant 10/49 versus MMC 9/50, RR 1.21 [95% CI 0.56 to 2.6], p=0.62) (Wang 2015).

Positive Seidel test

In the Cochrane review, pooled analysis of 3 studies (including 164 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for positive Seidel test (collagen implant 3/78 versus MMC 1/86, RR 1.93 [95% CI 0.32 to 11.54], p=0.47) (Wang 2015).

Tenon's cysts

In the Cochrane review, pooled analysis of 3 studies (including 124 eyes) comparing trabeculectomy plus collagen implant with trabeculectomy plus MMC reported no statistically significant difference between the groups for Tenon's cysts (collagen implant 5/58 versus MMC 6/66, RR 0.88 [95% CI 0.21 to 3.66], p=0.86) (Wang 2015).

Suture lysis

In the meta-analysis of 11 studies, 1 study reported a statistically significantly higher incidence of suture lysis in the MMC group (collagen implant 3/20 versus MMC 10/20, pooled RR 0.30 [95% CI 0.10 to 0.93], p=0.04) (Song 2019).

Needling

In the meta-analysis of 11 studies, 1 study reported that the rate of needling was not significantly different between the groups (collagen implant 0/20 versus MMC 4/20, pooled RR 0.11 [95% CI 0.01 to 1.94], p=0.13) (Song 2019).

Central retinal vein occlusion

Central retinal vein occlusion following trabeculectomy with biodegradable collagen implant in the early postoperative period was reported in 3 cases in a case report. Two patients had decreased visual acuity and 1 patient had blurred vision and retinal haemorrhages involving the macula (Tranos 2010).

Cataract

One eye in each group developed a cataract in the RCT of 33 patients (40 eyes) comparing a shunt device (20 eyes) with collagen implant (20 eyes) at 6 months follow up (Bhatkoti 2021).

Postoperative complications

The rate of postoperative complications was lower in the shunt group compared to the collagen implant group, in both early (within 30 days) (35% [7/20] versus 50% [10/20]) and late follow up (20% [4/20] versus 30% [6/20]) in the RCT of 33 patients (40 eyes) (Bhatkoti 2021).