https://doi.org/10.1177/1120672120979903 European Journal of Ophthalmology 1–6 © The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1120672120979903 journals.sagepub.com/home/ejo EJO European Journal of Ophthalmology Introduction Glaucoma is a leading cause of blindness worldwide. It is estimated that it will affect 79.6 million people around the globe by 2020. 1 To date, intraocular pressure (IOP) is the only modifiable risk factor to prevent progression of glaucoma. 2–7 The goal of management is to stabilize the remaining visual field, by setting a target IOP and achiev- ing and maintaining it over time. Studies have shown that eyes having severe glauco- matous damage need lower intraocular pressures. 8 Target IOP in Advanced Glaucoma Intervention Study (AGIS) was < 18 mmHg, however, a post hoc analysis showed that in these stable eyes, the average IOP was 12.3 mm Hg. Even eyes that had a mean IOP in the mid-teens showed progression by 2.5 dB over a period of 6 years. On analysis, Palmberg 9 found a 30% chance of progression if the IOP remained in the mid-teens, and 70% if IOP was 20 mmHg. Achieving low target intraocular pressures in severe glaucoma Gazella Bruce Warjri 1 , Talvir Sidhu 1 , Azmira Kishan 1 , Aswini Kumar Behera 1 , Jyoti Shakrawal 1 , Harathy Selvan 1 , Tanuj Dada 1 , Veena Pandey 2 and Ramanjit Sihota 1 Abstract Purpose: This study aimed to assess details of therapy required to achieve an intraocular pressure (IOP) of ⩽12 mmHg in patients with severe glaucoma of different etiologies. Methods: Patients with a follow-up of at least 1 year, who fulfilled inclusion criteria were selected, and data analyzed with respect to baseline IOP, number of medications, and/or surgeries required to achieve an IOP of ⩽12 mmHg and ⩾6 mmHg. Final IOP, visual field status and medications/surgery required were noted. Results: About 127 eyes of 85 patients met all criteria. There were 48 eyes having primary angle closure glaucoma (PACG), 16 eyes with primary open angle glaucoma (POAG), 17 eyes of juvenile open angle glaucoma (JOAG), and 46 eyes of secondary glaucoma. The mean baseline IOP was 33.14 ± 11.07 mmHg and final IOP 10.25 ± 1.81 mmHg. In the age group >40 years, 29.63% of patients were controlled on medication as compared to 9.09% and 5.71% in the age group of <20 years and 20–40 years (p = 0.007). With a baseline IOP of <25 mmHg, 48.65% required a trabeculectomy, whereas for 25–30, and >30 mmHg, 62.5% and 97.29% respectively, required surgery (p < 0.001).66.67% of patients having mean deviation of −12 to −16 dB (decibels) on Humphrey field analyzer (HFA) underwent surgery to achieve target IOP in comparison to 83.52% who had mean deviation greater than −16 dB (p = 0.036). Conclusion: Only 21.26% of severe glaucoma eyes could be controlled on medications alone. A baseline IOP of >25 mmHg, age <40 years and mean deviation worse than −16 dB, had a higher frequency of trabeculectomies to achieve an IOP of ⩽12 mmHg. Keywords Epidemiology/risk factors, glaucoma, open angle glaucoma, angle closure, glaucoma medical therapies, glaucoma incisional surgery Date received: 22 September 2020; accepted: 3 November 2020 1 Glaucoma Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India 2 Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India Corresponding author: Ramanjit Sihota, Glaucoma Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, AIIMS, New Delhi 110029, India. Email: rjsihota@gmail.com 979903EJO 0 0 10.1177/1120672120979903European Journal of OphthalmologyWarjri et al. research-article 2020 Original research article