Purpose: This study aims to evaluate the early to the midterm efficacy of deep sclerectomy (DS) without an intra-scleral spacer for open-angle glaucoma (OAG) patients. Materials and methods: Retrospective study of 99 eyes (88 patients) with open-angle glaucoma who underwent DS were recruited in a consecutive order following informed consent. Intraocular pressure (IOP) was collected up to 60 months post operation (mean 19.87 ± 15.13 months). Criteria of success were defined as the qualified success (QS) or complete success (CS) with IOP level less than 21, 18 and 15 mm Hg and a reduction of more than 20% IOP from baseline. QS includes additional medication post-DS, while CS requires no other medications or surgery post-DS. Further analysis includes comparing the criteria of success based on several factors. The data were analyzed using statistical package for social sciences (SPSS version 21) statistical software. Results: The QS at 60 months for IOP less than 21, 18 and 15 mm Hg is 71.3% (45.12 ± 2.46), 63.9% (40.41 ± 2.75) and 48.7% (35.62 ± 2.85), respectively. The CS at 60 months for IOP less than 21, 18 and 15 mm Hg are 69.3% (47.51 ± 2.77), 57.9% (40.41 ± 2.75) and 45.2% (35.62 ± 2.85), respectively. There was no significant difference between QS and DS post-DS based on the level of experience of the surgeons; intraoperation complication; age and gender. There was a significant reduction in IOP post operation (p < 0.001). Conclusion: DS is observed to be an effective surgical method with a favorable safety profile to manage patients with open-angle glaucoma. It has a better safety profile compared to trabeculectomy (TE) and can be performed by surgeons of different experience safely and successfully. Clinical significance: To our knowledge, this is the first report of DS in an Australian population with up to 60 months of follow-up. It is an effective procedure for IOP control in patients with OAG and has fewer complications compared to TE. DS is less popular than TE primarily due to a perceived steep learning curve, but most of the literature on DS describe single surgeon results. Our study compared the outcome of five surgeons with a variety of experience and found no significant differences in the rate of success for all levels of IOP.