Background <p>Endogenous cortisol excess is a rare cause of secondary open-angle glaucoma and may be overlooked when its early systemic manifestations are mild or nonspecific. As a result, diagnosis is often delayed until irreversible optic nerve damage has occurred, unlike the more commonly encountered corticosteroid-induced intraocular pressure elevation seen with exogenous corticosteroid use.</p> Case presentation <p>We report the case of a 30-year-old woman, one year postpartum, who presented with progressive visual loss and elevated intraocular pressure (IOP) in both eyes. Ocular examination revealed bilateral open angles, corneal edema, and glaucomatous damage to the optic nerve in the left eye. Despite maximal medical therapy and anterior chamber paracentesis, IOP remained uncontrolled, necessitating bilateral trabeculectomies. After surgery, IOP stabilized around 10 mmHg and visual acuity improved. During postoperative follow-up, further history revealed a 20-kg weight gain within one year postpartum and persistent physical changes. Physical examination identified centripetal obesity, abdominal striae, and a moon face, raising suspicion for Cushing’s syndrome. Given the atypical ocular course, these findings raised suspicion of endogenous corticosteroid-induced glaucoma. Although IOP had already been surgically controlled, the atypical ocular course and systemic features prompted referral to internal medicine. Endocrinological evaluation subsequently confirmed Cushing’s syndrome due to a cortisol-secreting left adrenal adenoma, which was surgically removed. Following adrenalectomy, cortisol levels normalized and systemic manifestations gradually resolved.</p> Conclusions <p>Recognition of endogenous cortisol excess as a potential cause of acute bilateral ocular hypertension highlights the need for systemic evaluation in atypical glaucoma and contributes to preventing irreversible visual loss through timely diagnosis and treatment.</p>