**9. Incidence of complications and adverse events**

Complications are listed in Table 5. In the trabeculectomy group, 5 eyes (12.5 %) exhibited hypotony and flat/shallow anterior chamber. In the trabeculotomy group, hyphema was observed in 14 eyes (33.3 %) and intraocular pressure spike in 3 eyes (7.1 %). All the bleeding disappeared within one week. No progression of cataract was found in the two groups.


**Table 5.** Incidence of complications

#### **10. Discussion**

There was no significant difference in hypotensive efficacy between patients undergoing trabeculotomy augmented by postoperative topical medication and those undergoing trabeculectomy augmented by mitomycin C at 12 months postoperatively. In the current study, 42 eyes (100 %) in the trabeculotomy group and 37 eyes (92.5%) in the trabeculectomy group were considered to be a success defined as an intraocular pressure of less than or equal to 20 mm Hg and a minimum of 30 percent reduction. There was no significant difference in the success rate or intraocular pressure between the trabeculotomy group and the trabeculectomy group at 12 months although the intraocular pressure was higher in the trabeculotomy group at every visit after surgery.

**Trabeculotomy augmented by postoperative medication group**

Topical medication 42 (100.0%) 8 (20.0%) 0.0023 Laser suture lysis 0 (0%) 15 (37.5%) < 0.0001 Needling 0 (0%) 6 (15.0%) 0.0091 5-fluorouracil injection 0 (0%) 0 (0%) - Additional surgery 0 (0%) 3 (7.5%) 0.1

Complications are listed in Table 5. In the trabeculectomy group, 5 eyes (12.5 %) exhibited hypotony and flat/shallow anterior chamber. In the trabeculotomy group, hyphema was observed in 14 eyes (33.3 %) and intraocular pressure spike in 3 eyes (7.1 %). All the bleeding disappeared within one week. No progression of cataract was found in the two groups.

> **Trabeculotomy augmented by postoperative medication group**

Hypotension 0 (0%) 5 (12.5%) 0.0181 Shallow/flat anterior chamber 0 (0%) 5 (12.5%) 0.0181 Choroidal detachment 0 (0%) 1 (2.5%) 0.3 Intraocular pressure spike 3 (7.1%) 0 (0%) 0.1 Hyphaema 14 (33.3%) 2 (5.0%) 0.0012 Flat bleb - 5 (12.5%) - Anterior iris synechia 0 (0%) 0 (0%) - Posterior iris synechia 0 (0%) 0 (0%) -- Progression of cataract 0 (0%) 0 (0%) - Blebitis/endophthalmitis 0 (0%) 0 (0%) -

There was no significant difference in hypotensive efficacy between patients undergoing trabeculotomy augmented by postoperative topical medication and those undergoing

Number of patients 42 40

**Table 4.** Postoperative intraocular pressure-lowering procedure

100 Advances in Eye Surgery

**Table 5.** Incidence of complications

**10. Discussion**

**9. Incidence of complications and adverse events**

**Trabeculectomy group P**

**Trabeculectomy group P**

Each surgery had its own advantage. In the trabeculotomy group, all patients showed an intraocular pressure of less than or equal to 20 mm Hg at 12 months. However, patients with higher preoperative pressure showed a relatively higher intraocular pressure at 12 months even though it was less than 20 mm Hg. There was a significant increase in the intraocular pressure at 12 months in relation to the increase in preoperative intraocular pressure. Postop‐ erative intraocular pressure was calculated from the preoperative intraocular pressure by using a correlation equation as follows:

[Intraocular pressure at 12 months] = 0.26 x [preoperative intraocular pressure] + 7.71 (r2 =0.440, P < 0.0001).

Patients receiving trabeculotomy experienced less postoperative surgical interventions than those receiving trabeculectomy. In addition, 3 patients in the trabeculectomy group underwent additional surgery although no patient in the trabeculotomy group did.

In contrast to the trabeculotomy group, there was no significant correlation between preop‐ erative intraocular pressure and postoperative intraocular pressure in patients undergoing trabeculectomy augmented by mitomycin C. This procedure can be employed in all patients to achieve lower postoperative pressure regardless of how high the preoperative intraocular pressure might be. At 12 months, there was a significantly larger percent of eyes of less than or equal to 12 mm Hg in patients undergoing trabeculectomy compared with trabeculotomy despite of postoperative medications. Several investigators have demonstrated that it was pivotal to set a target pressure and achieve it based on patients' visual function [12-15]. Patients with greater visual function deterioration need lower target pressures to maintain residual visual function. According to the target pressure, indication for each of these methodologies should be carefully considered prior to any surgical interventions.

This study has important limitations. The sample size of this study was small, therefore not powered to detect small differences. The small sample size also precluded assessment of safety. Furthermore, a masked study design could have reduced observer bias. The postoperative follow-up period also was short, and therefore we could not assess long-term efficacy and safety.

Although the sample size in each group was small, the current study demonstrated that (1) there was no significant difference in hypotensive efficacy between patients undergoing trabeculotomy augmented by postoperative topical medications and those undergoing trabeculectomy augmented by mitomycin C at 12 months postoperatively and (2) in those receiving trabeculotomy, patients with higher preoperative pressure showed a significantly higher intraocular pressure at 12 months even though less than 20 mm Hg. Future study of a large population is needed to verify these observations. However, this information may be clinically valuable when treating patients with open-angle glaucoma.
