Dear Editor, Hemodialysis remains the most commonly employed renal replacement therapy for patients with advanced renal dysfunction and is associated with rapid alterations in plasma osmolarity, intravascular volume, and systemic hemodynamics due to extracorporeal solute clearance and ultrafiltration.1 While these systemic effects are well recognized, their ophthalmic implications are often underappreciated in routine clinical practice. Transient fluctuations in intraocular pressure (IOP) during or shortly after hemodialysis have been reported in several studies. These changes are attributed to osmotic disequilibrium between plasma and intraocular fluids, altered aqueous humor dynamics, and variations in episcleral venous pressure.2 Although the direction and magnitude of IOP change are inconsistent, individuals with pre-existing glaucoma or ocular hypertension may be more susceptible, highlighting the importance of targeted ophthalmic surveillance in this subgroup.3 Posterior segment alterations have also been described, particularly involving choroidal thickness and ocular perfusion parameters. Hemodialysis-induced reductions in circulating blood volume and systemic blood pressure may influence choroidal circulation, given the highly vascular nature of this tissue. Such hemodynamic shifts may transiently affect optic nerve head perfusion and visual function. Notably, structural changes detected using imaging modalities do not consistently correlate with functional improvement in visual acuity, underscoring the need for comprehensive functional assessment rather than reliance on imaging findings alone.4 Ocular surface involvement is another frequently observed manifestation in patients undergoing long-term hemodialysis. Reduced tear breakup time and decreased Schirmer’s test values reflect tear film instability and predispose patients to dry eye disease, likely due to dehydration, altered electrolyte balance, and autonomic dysfunction.5 Early recognition and management of ocular surface disease are essential to improve visual comfort and overall quality of life. Importantly, the timing of ophthalmic evaluation in relation to the dialysis session plays a critical role in the interpretation of findings. Assessments performed immediately after hemodialysis may reflect transient physiological instability rather than true baseline ocular status. Delaying ophthalmic examination by a few hours after dialysis may therefore provide a more reliable assessment of IOP, ocular surface parameters, and posterior segment circulation. In summary, it is already known that hemodialysis induces transient systemic and hemodynamic changes that may influence ocular physiology. This letter adds a concise synthesis of recent ophthalmic evidence emphasizing the timing-dependent and largely reversible nature of these ocular changes, highlighting the importance of appropriately timed ophthalmic evaluation to avoid misinterpretation of transient findings in patients undergoing regular hemodialysis. Data availability statement Data supporting the findings of this manuscript are available from the corresponding author upon reasonable request. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Chandra et al. (Wed,) studied this question.