Subscleral Trabeculectomy with Ologen implant versus Mitomycin C in primary infantile glaucoma: up to 103 months’ follow-up

doi:10.21203/rs.3.rs-2734611/v1

Purpose

To compare the effect of SST augmented with Mitomycin C (MMC) versus Ologen implant as secondary procedures for treatment of primary congenital glaucoma.

Methods

This is a retrospective study evaluating records of 38 eyes that had undergone SST with MMC (group M, 17 eyes) versus Ologen (Group O, 21 eyes), by authors of the study. The study primary endpoint was set at 5 to 9 months postoperatively and the secondary endpoint was the last follow-up. A successful outcome was an IOP </=18 mmHg for infants < 1 year, and </= 20 mmHg for older ones.

Results

Follow-up duration was 1.25 to 51 (26.79 +/- 27.583) months in group M, and 0.25 to 103 (22.86+/-28.991) months in group O (p = .673). The mean preoperative IOP was 28.06+/-3.929 in group M and 26.95+/-6.095 in group O (p = .522). Reduction of IOP was significant in group M at all follow-up visits, but starting at the fourth postoperative month in group O. Recorded IOP in groups M and O, respectively, was 14.9+/-6.437 and 12.1+/-5.043 at the primary endpoint, and 22.35+/-8.536 and 22.52+/-10.152 (p > .05) at the secondary endpoint. A successful outcome was achieved in groups M and O, respectively, in 47.1% and 47.6% at the primary endpoint and in 47.1% and 52.4% at the secondary endpoint (p > .05). Cataract, posterior synechiae and pupillary abnormalities were insignificantly different in both groups (p = .623).

Conclusions

Ologen implant was comparable to MMC, in terms of efficacy and safety. Reoperations are inadvisable prior to 4 months of Ologen implants.

Health sciences/Diseases

Health sciences/Diseases/Eye diseases

Health sciences/Diseases/Eye diseases/Ocular hypertension

Health sciences/Diseases/Eye diseases/Ocular hypertension/Glaucoma

Biodegradable collagen matrix implant

Bleb

Intraocular pressure

Mitomycin C

Ologen

primary congenital glaucoma

primary infantile glaucoma

subscleral trabeculectomy.

- Untreated primary congenital glaucoma results in visual loss due to elevated IOP with subsequent corneal edema, Haab striae, amblyopia, and optic nerve damage.

- In case of failed angle surgery, subscleral trabeculectomy or glaucoma valves become the treatment options.

- The high rate of postoperative fibrosis in the pediatric age group makes failure of subscleral trabeculectomy inevitable without the use of adjuvants to limit fibrosis.

- Mitomycin C is one option but has a high rate of potential complications. Ologen is a biodegradable collagen matrix implant is presumably a safer wound healing modulator.

- This study compared subscleral trabeculectomy with Mitomycin C versus Ologen implant. Ologen implant was found comparable in efficacy to Mitomycin C.

Primary congenital or infantile glaucoma results from developmental angle and trabecular meshwork anomalies, leading to defective aqueous outflow, with subsequent elevated intraocular pressure (IOP). It has an onset between birth to 4 years of age and is often associated with significant visual loss due to elevated IOP with subsequent corneal edema, Haab striae, amblyopia, and optic nerve damage. Surgery is the mainstay of treatment starting with goniotomy or trabeculotomy and ending with subscleral trabeculectomy (SST) or glaucoma drainage devices.^1,2

The success of SST to treat primary congenital glaucoma (PCG) in children is lower than in adults with primary open-angle glaucoma (POAG), because of the exaggerated healing reaction in young eyes, resulting in subconjunctival scarring in the filtering bleb.³ The adjuvant use of antimetabolites, such as mitomycin C (MMC) or 5-fluorouracil (5-FU), during SST was, therefore, recommended to limit the scarring process. Mitomycin C is, however, associated with a higher risk of post-operative complications.⁴

The biodegradable collagen matrix implant, Ologen™, (Aeon Astron Europe BV, Leiden, The Netherlands) may be used as an alternative wound-healing modulator. It consists of a collagen-based scaffold containing thousands of microscopic pores. The implant is placed over the scleral flap and influences the healing process by forcing fibroblasts and myofibroblasts to grow into the pores and secrete connective tissue in the form of loose matrix. This, theoretically, results in decreased scar formation and improved surgical success of SST, while avoiding the risks of antimetabolites.⁵

This is a retrospective study involving the records of 38 eyes of Egyptian children affected with primary congenital glaucoma. The study was conducted in the department of pediatric ophthalmology and strabismus of the Children’s hospital of Cairo University. The study conformed to local laws and the declaration of Helsinki. Approval of the study was obtained from the scientific committee and council of the Ophthalmic department, and the council of the Faculty of Medicine of Cairo University. Informed consent was obtained from parents of children included in the study.

Inclusion criteria involved: records of all patients who underwent SST with MMC in one eye and Ologen implant in the fellow eye by the authors of the study. Patients were operated upon and followed up between January 2012 till June 2021. All patients had to fulfill the following criteria before surgery: bilateral primary infantile glaucoma, with onset below 4 years of age, who had at least 1 previous failed glaucoma surgery, with IOP higher than 18 mmHg if below 1 year of age and higher than 21 mmHg if above 1 year of age. Exclusion criteria involved absence of any of the above criteria.

Preoperative evaluation included: history taking for sex, age, age at onset, consanguinity, medications, previous surgeries, other ocular or general diseases. Preoperative examination was carried out under sedation with chloral hydrate (ml taken were equivalent to 50 to 80% of body weight in kg). Topical anesthesia with Benoxinate hydrochloride 0.4% eye drops was applied. Eyes were examined for corneal clarity (scored as 0 = clear, 1 = Haab’s striae, 2 = mild haze, 3 = moderate haze, 4 = dense opacity), horizontal corneal diameter, central corneal thickness (CCT), IOP (measured by Perkins hand-held applanation tonometer, Haag-Streit, UK), cup/disc ratio, in addition to complete anterior and posterior segment evaluation, and cycloplegic refraction.

Eyes underwent surgery in the form of SST with either MMC (Group M) or Ologen implant (Group O). Surgery was performed under general anesthesia by authors of the study. A corneal traction suture using 7/0 Vicryl (occasionally a superior rectus bridle suture) was applied. A superior fornix-based conjunctival flap was created followed by diathermy and creation of a scleral flap. In group M, MMC (0.2-0.4mg/ml) was applied for 2–4 minutes either subconjuctival or both subconjunctival and subscleral. This was followed by trabeculectomy and closure of scleral flap with 10/0 nylon sutures. In group O, no MMC was used. Instead, after trabeculectomy, Ologen implant (Ologen™, Aeon Astron Europe BV, Leiden, The Netherlands) was applied over the repositioned sutureless scleral flap. In 4 eyes of Group O, the Ologen implant was divided and one piece was placed under and the other over the sutured scleral flap. In all cases of both groups, Healon or methyl cellulose were used to reform the anterior chamber as necessary. At the end, the conjunctiva was closed with 10/0 nylon sutures. Subconjunctival diprofoss was injected in most cases. All eyes were patched.

Postoperative medications prescribed included: steroid eye drops 6 times daily and tapered over 6 weeks, broad-spectrum antibiotic eye drops 4 times daily, and cycloplegic eye drops 3 times daily. Antibiotic-steroid eye ointment was used by night for 6 weeks.

Postoperative evaluation was scheduled at: 1 day, 1 week, 1 month, monthly till 6 months, then every 3 months. Chloral hydrate sedation and topical anesthesia, using Benoxinate hydrochloride 0.4% eye drops, were used in younger children. Cooperative children, growing older, however, were examined under topical anesthesia without sedation.

At each follow-up visit, examination was performed in the same manner as done preoperatively in addition to bleb evaluation, based on Moorfield’s bleb scoring system, with modification. Blebs were scored for: area (1 = 0%, 2 = 25%, 3 = 50%, 4 = 75%, 5 = 100% of superior 180-degree conjunctiva), maximal height (0–4), and vascularity (1 = avascular, 2 = normal vascularity, 3 = mild hyperemia, 4 = moderate hyperemia, 5 = severe hyperemia). During the first postoperative week, special attention was paid for anterior chamber depth or abnormal contents (hyphema, hypopyon, flare, or cells), and IOP was evaluated digitally, and given a score of 1 (very low), 2 (low), 3 (normal), 4 (high) and 5 (very high).

The study primary endpoint was set at the closest follow-up to 6 months’ postoperatively between 5 to 9 postoperative months. The secondary endpoint was considered the last follow-up visit. If a glaucoma reoperation or cyclodiode (but not needling or anterior chamber reformation) was done at any stage, termination of postoperative documentation of results of the former operation ensued.

A successful outcome was defined as IOP 18 mmHg or less (if 1-year-old or younger) or 20 mmHg or less (if older than 1 year) without anti-glaucoma medications (complete success) or with anti-glaucoma medications (qualified success).

Records of 38 eyes of Egyptian children with primary congenital glaucoma, that had been treated with SST with either MMC (Group M, 17 eyes) or Ologen implant (Group O, 21 eyes), were retrospectively analyzed as part of this study. Patients in group M were followed up for 1.25 to 51 (26.79 +/- 27.583) months, and in group O for 0.25 to 103 (22.86+/-28.991) months (p =.673). Details of preoperative and operative data are listed in Table 1, which shows harmonious distribution of all parameters between both groups (p >.05). Postoperative data are shown in Table 2, which revealed insignificant differences between both groups, except for significantly greater bleb area and height at 1 month as well as bleb area at 4 months postoperatively in group O. Intraocular pressure was significantly reduced after surgery during all follow-up visits in group M, while its reduction became significant in group O only starting 4 months postoperatively. Postoperative data are highlighted in Figure 1. Outcome at each follow-up visit is shown in Table 3, which revealed insignificant differences in success rates between the 2 groups. Figure 2a summarizes data of the last follow-up for all patients. Figure 2b highlights the survival in both groups. There was an early survival drop in both groups, followed by a plateau that was longer in Group O, followed by another drop.

First week postoperative adverse effects were recorded in 6 of 12 examined M eyes (50%), and in 11 of 18 examined O eyes (61.1%). These included [n (%)] in M then O: hyphema [0 (0%), 1 (5.6%)], hypotony [5 (41.7%), 7 (38.9%)], high IOP [0 (0%), 1 (5.6%)], shallow anterior chamber [3 (25%), 4 (22.2%)], lost anterior chamber [1 (8.3%), 4 (22.2%)], choroidal effusion [1 (8.3%), 1 (5.6%)], and exudative retinal detachment [1 (8.3%), 0 (0%)]. Adverse effects encountered later were recorded in 6/17 M eyes (35.3%) and in 6/21 O eyes (28.6%). These included: cataract recorded in 1 eye (5.9%) in group M and in 2 eyes (9.5%) in group O, posterior synechiae and/or pupillary abnormalities seen in 5 eyes (29.4%) in group M and in 4 eyes (19.05%) in group O (p>.05).

It is well known that episcleral fibrosis and subconjunctival scarring, causing obstruction of aqueous outflow, are the major causes of failure in glaucoma filtering surgery. Antimetabolites such as MMC and 5-fluorouracil, are used to modulate wound healing in glaucoma filtering surgery (3). Mitomycin C is a chemotherapeutic agent, that acts by inhibiting synthesis of DNA, cellular RNA, and protein, thus inhibiting the synthesis of collagen by fibroblasts.⁶

Mitomycin C has been widely used for enhancing the success rate of glaucoma filtration surgery and postoperative IOP reduction.⁷ However, it is frequently accompanied by short- and long-term complications such as hypotony, bleb leaks, cataract formation, avascular filtering blebs, thinning of the conjunctiva, blebitis, and endophthalmitis.⁸ This urged for a safer alternative for fibrosis control.

Ologen, a collagen matrix implant for wound modulation, may reduce these problems. It was developed, aiming at replacing MMC for trabeculectomy. It is a disc-shaped artificial porcine extracellular matrix made of atelocollagen cross-linked with glycosaminoglycan. When inserted under the conjunctiva at the time of trabeculectomy, it mechanically separates the conjunctiva and episcleral surface and prevent adhesions between them. Moreover, Ologen is a scaffolding matrix that induces a regenerative wound healing process, minimizing the random growth of fibroblasts and, instead, promoting their growth through the pores in the matrix without the need for antifibrotic agents. This prevents scarring. Ologen is biodegradable in 90 to 180 days.^5.9–11

Ologen implant during SST was previously used to treat POAG in adults with variable results. Some studies found Ologen comparable to MMC,^12–17 whereas others found Ologen inferior to MMC in its IOP lowering effect.^18,19

Glaucoma in the pediatric age group is different from adults in several respects. First, the pathology is different, where there is congenital angle anomaly (trabeculodysgenesis) in PCG, which warrants angle surgery (goniotomy or trabeculotomy) prior to resorting to SST.^2,20 If SST is eventually needed, it will be done on a non-virgin globe, where subconjunctival and subscleral fibrosis and adhesions have followed trabeculotomy, and peripheral anterior synechiae might have complicated goniotomy or trabeculotomy. Second, scarring is more pronounced in the pediatric age group than in adults, which limits the success rate of any surgery including SST.^2,3 Third, the normal and, in turn, the target IOP in the pediatric age group is much lower than in adults. This was estimated as 11.5 ± 2.34 mmHg in Egyptian children up to 12 years of age and 10.74 ± 2.3 mmHg in Egyptian infants below 1-year of age.²¹ Fourth, antiglaucoma drugs are used in pediatrics on temporary basis and not life-long, so a qualified success is actually a temporary success. Fifth, amblyopia is always a risk in pediatrics, necessitating urgent control of IOP, correction of refractive errors, and patching as indicated.²

The present study compared Ologen to MMC as adjuvants to SST for treatment of primary congenital glaucoma in Egyptian pediatrics. This study represents the longest follow-up, reaching 103 months. The present study recorded a success rate in groups M and O of 47.1% and 47.6%, respectively, at the study end-point, and 47.1% and 52.4%, respectively, at the last follow-up, with insignificant differences between both groups. Adverse effects reported were also insignificantly different between both groups. These denote equivocal efficacy and safety of MMC and Ologen implants. This agrees with most adult studies on POAG. ^12–17

A single study compared SST augmented with MMC versus Ologen implant for treatment of juvenile open angle glaucoma.²² It was conducted in Egypt, by El-Sayyad et al., on 40 eyes of patients with a mean age of 23.3+/-4.3 years. The authors reported significantly lower IOP in MMC group during the first postoperative week, no significant difference from 1 to 6 months, then significantly lower IOP in the Ologen group at 1 year. In the present study, the differences in IOP between both groups were insignificant all through, yet it agrees with El-Sayyad et al. in reporting a lower IOP at 1 year in group O (10.5+/-4.504) versus M (16+/-7.681), p = .097.

Two studies evaluated the effect of Ologen implants in PCG, and were conducted in Egypt, but in institutions other than that of the present study.^23,24 El-Hefny et al.²³ evaluated the effect of Ologen implant in 20 eyes with infantile glaucoma, as an adjuvant to combined trabeculotomy-trabeculectomy, as a primary procedure. On the contrary, trabeculectomy was not combined with trabeculotomy in the present study, although some cases had had an earlier trabeculotomy that had failed. Comparing their study to group O of the current study, the current one included older patients of 24.48+/-29.44 months versus 5.7+/-5.69 in the earlier study. This could be related to operating only on eyes with previous failed angle surgery in the present study, unlike the previous one that excluded eyes that had undergone any previous glaucoma surgeries. The present study reported a longer follow-up of 22.86+/-28.99 months versus 10.05+/-1.15 months in the previous one. In group O of the present study, the mean preoperative IOP was 26.95+/-6.095 mm Hg and dropped to 10.5+/-4.5 at 10–12 months, while it was 25.9+/-3.08 and dropped to 17.7+/-3.51 mmHg at 12 months postoperatively in the earlier study. This suggests that previous angle surgery or even SST, presumably, does not affect the IOP lowering effect of subsequent SST with Ologen implant. Studies on larger sample sizes are, however, necessary to prove this assumption and further support the inclination towards angle surgery as a primary procedure prior to resorting to SST, which is the trend in our institution and in the literature,² due the reported higher complications rate of the latter especially if MMC is used as an adjuvant.⁴

El-Hefny et al.²³ reported an early rise of IOP during the first postoperative month and attributed this to absorption of aqueous by Ologen, which pressed on the scleral flap, providing resistance to aqueous outflow, which decreased as the implant biodegraded. This agrees with the present study, where IOP was higher during the first 3 months than during later visits, and bleb height was maximum during the first month (Table 2 and Fig. 1). This is consistent with previous studies, reporting the biodegradation of Ologen over 30 to 180 days.^23,25,26 This prompts attention to avoid early reoperation after Ologen implant assuming early failure. This also was the justification behind application of Ologen over a sutureless scleral flap in the present study, to avoid the need for postoperative laser suture lysis, as the implant would support the flap.

El-Hefny et al.²³ reported no complications or signs of toxicity or inflammation in their cases. On the contrary, cataract, posterior synechiae and/or pupillary abnormalities were seen in 6/21 eyes (28.6%) in group O. Group M, however, had a rather similar rate of 6/17 eyes (35.3%).

Singab et al.²⁴ conducted a study on 34 eyes, comparing combined trabeculotomy-trabeculectomy with Ologen implant versus MMC to treat primary congenital glaucoma. Similar to El-Hefny et al.,²³ and contrary to the present study, the authors²⁴ excluded patients who had undergone previous glaucoma surgeries. Singab et al.²⁴ applied Ologen both under and over the scleral flap. This was done in 4 eyes of the present study, while it was applied only over the scleral flap in the rest. Three of these 4 eyes (75%) had a successful outcome at the last visit, while a successful outcome was achieved in only 5/17 eyes (29.4%) that had Ologen only over the scleral flap. Singab et al. ²⁴ recorded an IOP higher than 20 mmHg at 12-month follow-up in only 13.3% of their cases. Their results and that achieved in the present study draw attention to the superiority of combined subscleral and subconjunctival Ologen application over mere subconjunctival Ologen application. This is theoretically explained by the presumption that Ologen controlled postoperative scarring in both the subscleral and subconjunctival spaces if placed in both spaces, while it controlled scarring only in the subconjunctival space if placed only subconjunctivally. This, however, needs further evaluation by large-sample comparative studies.

Similar to the present study, Singab et al.,²⁴ reported no significant differences in postoperative IOP levels or complications rate in Ologen versus MMC groups during their 12 months of postoperative follow-up (p > .05).

In conclusion, Ologen implant was comparable to MMC as an adjuvant to SST for treatment of PCG, in terms of efficacy and safety. Although IOP reduction was significant after SST with MMC during at all follow-up visits, it was only significant with Ologen implants starting 4 months following surgery, which could be attributed to resistance to aqueous outflow by the Ologen implant prior to its degradation. The authors, therefore, advise against reoperations prior to 3 months after Ologen implant. If Ologen is opted for, the authors recommend its application both subconjunctivally and subsclerally. Further studies on a larger sample size are encouraged.

The author declares no conflict of interest. This work was not, and is not scheduled to be, presented at any conference. The authors declare no financial relationship with any organization.

ACKNOWLEDGEMENTS

FUNDNG

The manuscript was self-funded by the authors.

DISCLOSURES

The authors (Rehab Kassem and Amanne Esmael) declare no competing interests.

COMPLIANCE WITH ETHICS GUIDELINES

The study conformed to local laws and the declaration of Helsinki. Approval of the study was obtained from the scientific committee and council of the Ophthalmic department, and the council of the Faculty of Medicine of Cairo University.

DATA AVAILABILITY

All underlying data is made available from the corresponding author on reasonable request.

THANKING

The authors would like to thank all parents of patients involved in the study as well as nurses of the pediatric glaucoma clinic.

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Table 1. Preoperative and operative data.

	Group M (N=17)	Group O (N=21)	M vs O (p values)
I. Preoperative data:
A. History
1. Sex: - Males (n,%) - Females (n,%)	9 (52.9%) 8 (47.1%)	9 (42.9%) 12 (57.1%)	.536
2. Age (months), mean+/-SD	14.71+/-17.737	24.48+/-29.441	.237
3. Age at onset (months), mean+/-SD	.2+/-.775	.5+/-1.543	.5
4. Duration (months), mean+/-SD	10.47+/-7.444	23.89+/-29.356	.095
5. Positive consanguinity (n, %)	9 (52.9%)	9 (42.9%)	.536
6. Number of previous surgeries, mean+/-SD	1.82+/-.883	1.9+/-.889	.78
7. Timing of last surgery (months), mean+/-SD	7.733+/-8.24	13.013+/-17.129	.28
8. Anti-glaucoma medications (n, %)	15 (88%)	17 (81%)	.117
B. Examination
1. Corneal clarity (n, %): - Clear = 0 - Haab’s striae = 1 - Mild opacity = 2 - Moderate opacity = 3 - Dense opacity = 4 - Mean+/-SD	1 (6.7%) 1 (6.7%) 3 (20%) 5 (33.3%) 5 (33.3%) 2.8+/-1.207	5 (23.8%) 2 (9.5%) 4 (19%) 3 (14.3%) 7 (33.3%) 2.238+/-1.609	.548
2. Horizontal corneal diamter (mm), mean+/-SD	13.016+/-.878	12.833+/-.808	.517
4. Intraocular pressure (mmHg), mean+/-SD	28.06+/-3.929	26.95+/-6.095	.522
5. Cup/disc ratio, mean+/-SD	.65+/-.19	.557+/-.203	.243
II. Operative data:
1. Site (n,%): - New - Reoperation	10 (62%) 6 (37.5%)	14 (77.8%) 4 (22.2%)	.329
2. Viscoelastic (n,%): - Healon - Methyl cellulose - None	3 (20%) 4 (26.7%) 8 (53.3%)	8 (38.1%) 8 (38.1%) 5 (23.8%)	.183

Table 2. Data of postoperative follow-up.

Preop./Postop. FU	Group	Tested Variables (n, mean+/-SD)
		Corneal clarity	HCD	IOP	IOP reduction	AGM	C/D	Bleb
		Corneal clarity	HCD	IOP	IOP reduction	AGM	C/D	Area	Height	Vascularity
Preop.	M	2.8+/-1.207	13.016+/-.878	28.06+/-3.929	-	1.4+/-.507	.65+/-.19	-	-	-
Preop.	O	2.238+/-1.609	12.833+/-.808	26.95+/-6.095	-	1.25+/- .716	.557+/-.203	-	-	-
1 w	M	11, 2.27+/-1.489	7, 12.714+/-1.41	15, 2.67+/-0.9	-	0	3, .2+/-.1	7, 3+/-1.414	6, 1.5+/-1.225	6, 4.83+/-.408
	O	15, 2.33+/-1.589	10, 12.45+/-.956	15, 2.57+/-1.21	-	0	4, .35+/-.173	7, 2.71+/-.488	8, 2.25+/-.886	6, 4.17+/-.753
	p	.933	.65	.589	-	-	.243	.623	.207	.086
1 m	M	13, 2.31+/-1.377	12, 12.69+/-.924	14, 17.79+/-6.852	14, 10.57+/-6.745 (p<.001)*¹	14, .29+/-.611	8, .55+/-.22	9, 1.56+/-.527	9, 1+/-1.118	9, 4.33+/-.707
	O	12, 2.5+/-1.732	7, 12.64+/-1.215	15, 22.53+/-11.801	15, 4+/-14.658 (p=.308)¹	13, .54+/-.776	4, .525+/-.34	10, 3+/-.667	10, 2.7+/-.823	10, 4.5+/-.707
	p	.323	.929	.201	.137	.354	.879	<.001*	.001*	.615
2 m	M	11, 2.82+/-1.328	11, 12.8+/-1.065	14, 21.36+/-10.142	14, 6.21+/-8.267 (p.=.015)*¹	13, .77+/-.725	7, .4+/-.231	8, 2.25+/-.886	9, 1.44+/-.726	9, 4.11+/-1.054
	O	13, 2.33+/-1.557	9, 12.64+/-1.039	15, 21.53+/-9.425	15, 4.33+/-10.795 (p=.142)¹	15, .67+/-.617	6, .517+/-.299	10, 2.3+/-1.16	10, 1.4+/-1.265	9, 3.78+/-1.093
	p	.804	.745	.962	.605	.689	.444	.921	.927	.52
3 m	M	3, 2.67+/-1.155	4, 13.375+/-1.109	5, 13.2+/-4.087	5, 15+/-4.472 (p=.002)*¹	5, .8+/-.837	4, .425+/-.33	2, 2.5+/-2.121	2, 1+/-1.414	2, 4.5+/-.707
	O	12, 2.67+/-1.557	9, 12.417+/-.919	13, 21.46+/-12.163	13, 6.46+/-13.295 (p=.105)¹	11, .55+/-.522	7, .5+/-.265	8, 1.88+/-.641	8, 1.25+/-1.165	8, 3.75+/-1.165
	p	.52	.13	.163	.186	.465	.688	.434	.799	.421
4 m	M	9, 1.44+/-1.333	7, 13.25+/-.947	10, 14.6+/-5.816	10, 12.2+/-4.962 (p<.001)*¹	10, .4+/-.699	10, .54+/-.196	4, 1.75+/-.5	4, 1+/-.816	4, 2.25+/-.5
	O	6, 1.67+/-1.966	5, 13.1+/-.652	8, 15+/-3.665	8, 11.13+/-7.864 (p=.005)*¹	7, .29+/-.488	7, .433+/-.321	7, 2.57+/-.535	7, 1.86+/-.9	6, 3+/-.894
	p	.451	.767	.868	.728	.715	.448	.034*	.152	.17
5 m	M	6, 1.83+/-1.329	6, 12.54+/-.714	7, 15+/-4.933	7, 12.14+/-4.018 (p<.001)*¹	7, .86+/-.69	7, .543+/-.19	3, 2.33+/-.577	3, 1.33+/-.577	2, 4+/-1.414
	O	6, 1.83+/-1.472	5, 13.2+/-.837	7, 11.29+/-6.291	7, 14.86+/-11.423 (p=.014)*¹	6, .83+/-.983	5, .58+/-.148	4, 1.75+/-.5	4, 1.25+/-.957	3, 3.67+/-1.528
	p	.675	.192	.243	.564	.96	.724	.211	.9	.822
6 m	M	6, 1.67+/-1.212	5, 13.35+/-1.084	8, 13.88+/-6.854	8, 12.88+/-6.424 (p=.001)*¹	8, .38+/-.518	6, .483+/-.232	5, 2+/-.707	5, 1.2+/-.837	3, 3+/-0
	O	3, 3.33+/-0.516	3, 12.5+/-.5	6, 12.67+/-5.01	6, 11.33+/-10.558 (p=.047)*¹	6, .33+/-.516	3, .3+/-.1	2, 2+/-0	2, 2.5+/-.707	2, 2+/-1.414
	p	.153	.258	.722	.74	.884	.242	1.000	.114	.272
10-12 m	M	5, 2+/-1.225	4, 12.88+/-.629	9, 16+/-7.681	9, 10.67+/-6.265 (p=.001)*¹	9, .56+/-.726	8, .525+/-.183	3, 3+/-1	3, 1.67+/-.577	2, 3+/-0
	O	5, 1.8+/-1.304	4, 12.75+/-.957	8, 10.5+/-4.504	8, 15.13+/-9.613 (p=.005)*¹	8, .63+/-.916	6, .6+/-.155	5, 1+/-1	5, .6+/-.849	5, 2.2+/-.837
	p	.766	.834	.097	.27	.864	.435	.034*	.119	.257
End point	M	9, 1.56+/-1.13	9, 13.03+/-.972	10, 14.9+/-6.437	10, 12.1+/-6.064 (p=.001)*¹	10, .4+/-.516	11, .482+/-.204	10, 1.9+/-.568	10, 1.3+/-.949	8, 3.5+/-.756
	O	9, 1.56+/-1.74	8, 13.16+/-.719	10, 12.1+/-5.043	10, 13.8+/-9.114 (p=.003)*¹	10, .5+/-.707	9, .5+/-.194	8, 2+/-.535	9, 1.78+/-.972	6, 2.83+/-1.472
	p	.204	.764	.293	.629	.722	.842	.708	.294	.289
Last follow-up	M	16, 1.75+/-1.693	12, 12.81+/-.847	17, 22.35+/-8.536	17, 5.71+/-6.762 (p=.003)*¹	17, .71+/-.588	11, .464+/-.206	12, 2+/-.603	12, 1.17+/-.835	10, 2.9+/-1.449
	O	19, 1.58+/-1.805	12, 12.79+/-1.102	21, 22.52+/-10.152	21, 4.43+/-10.81 (p=.075)¹	21, .71+/-.644	13, .515+/-.212	15, 1.8+/-.755	17, 1.18+/-1.185	14, 2.93+/-1.492
	p	.134	.959	.956	.674	.967	.552	.47	.981	.963
Postop. FU = Postoperative follow-up; w = week; m = months; M = Mitomycin C group; O = Ologen group; p = p value of M vs O; * = significant p value; ¹ = p values denote the significance of the amount of postoperative IOP reduction for each group; SD = Standard deviation; Success = Number and percentage of eyes with a successful outcome (complete + qualified success); Corneal clarity is graded as: 0 = clear, 1 = Haab’s striae, 2 = mild opacity, 3 = moderate opacity, 4 = dense opacity, and the mean of these is obtained; HCD = Horizontal corneal diameter (mm); IOP = Intraocular pressure (mmHg), except at 1 week, IOP is scored digitally from 1 (very low) to 5 (very high) and the mean score is recorded; IOP drop = Postoperative minus preoperative IOP; AGM = Number of antiglaucoma medications; C/D = Cup/disc ratio.

Table 3. Outcome of subscleral trabeculectomy with mitomycin C versus Ologen implant.

Outcome	Group	1w	1m	2m	3m	4m	5m	6m	End-point	10-12m	Last follow-up
Complete success	M	12 (70.6%)	7 (41.2%)	5 (29.4%)	2 (11.8%)	5 (29.4%)	2 (11.8%)	4 (23.5%)	6 (35.3%)	5 (29.4%)	6 (35.3%)
	O	15 (71.4%)	6 (28.6%)	4 (19%)	5 (23.8%)	6 (28.6%)	4 (19%)	4 (19%)	6 (28.6%)	5 (23.8%)	7 (33.3%)
Qualified success	M	0 (0%)	1 (5.9%)	1 (5.9%)	3 (17.6%)	3 (17.6%)	3 (17.6%)	2 (11.8%)	2 (11.8%)	2 (11.8%)	2 (11.8%)
	O	0 (0%)	0 (0%)	3 (14.3%)	0 (0%)	1 (4.8%)	3 (14.3%)	2 (9.5%)	4 (19%)	3 (14.3%)	4 (19%)
Total success	M	12 (70.6%)	8 (47.1%)	6 (35.3%)	5 (29.4%)	8 (47.1%)	5 (29.4%)	6 (35.3%)	8 (47.1%)	7 (41.2%)	8 (47.1%)
	O	15 (71.4%)	6 (28.6%)	7 (33.3%)	5 (23.8%)	7 (33.3%)	7 (33.3%)	6 (28.6%)	10 (47.6%)	8 (38.1%)	11 (52.4%)
Current failure	M	3 (17.6%)	6 (35.3%)	8 (47.1%)	0 (0%)	2 (11.8%)	2 (11.8%)	2 (11.8%)	3 (17.6%)	2 (11.8%)	9 (52.9%)
	O	6 (28.6%)	9 (42.9%)	7 (33.3%)	8 (38.1%)	1 (4.8%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	10 (47.6%)
Earlier failure (reoperated)	M	0 (0%)	0 (0%)	0 (0%)	6 (35.3%)	6 (35.3%)	6 (35.3%)	6 (35.3%)	6 (35.3%)	6 (35.3%)	-
	O	0 (0%)	0 (0%)	1 (4.8%)	4 (19%)	9 (42.9%)	9 (42.9%)	9 (42.9%)	9 (42.9%)	9 (42.9%)	-
Total failure	M	3 (17.6%)	6 (35.3%)	8 (47.1%)	6 (35.3%)	8 (47.1%)	8 (47.1%)	8 (47.1%)	9 (52.9%)	8 (47.1%)	-
	O	6 (28.6%)	9 (42.9%)	8 (38.1%)	12 (57.1%)	10 (47.6%)	9 (42.9%)	9 (42.9%)	9 (42.9%)	9 (42.9%)	-
Drop-out (or did not reach this length of follow-up)	M	2 (11.8%)	3 (17.6%)	3 (17.7%)	6 (35.3%)	1 (5.9%)	4 (23.5%)	3 (17.6%)	0 (0%)	2 (11.8%)	-
	O	0 (0%)	6 (28.6%)	5 (23.8%)	4 (19%)	4 (19%)	5 (23.8%)	6 (28.6%)	2 (9.5%)	4 (19%)	-
	P value (M vs O)	.705	.439	.596	.004	.544	.264	.417	.163	.342	.827
M = Group M = Mitomycin C group; O = Group O = Ologen group

No competing interests reported.

Subscleral Trabeculectomy with Ologen implant versus Mitomycin C in primary infantile glaucoma: up to 103 months’ follow-up

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