Abstract
PURPOSE: This study aimed to evaluate ocular structural parameters in children with attention-deficit/hyperactivity disorder (ADHD) and to investigate potential differences associated with Methylphenidate Hydrochloride (MPH) treatment. METHODS: In this cross-sectional case-control study, 193 children were included and divided into three groups: Group 1 comprised 56 ADHD patients receiving MPH, Group 2 included 55 drug-naïve ADHD patients, and Group 3 consisted of 82 healthy controls. All participants underwent comprehensive ophthalmologic examinations, including cycloplegic refraction, intraocular pressure (IOP), corneal topography, specular microscopy, and spectral-domain optical coherence tomography (SD-OCT). Retinal nerve fiber layer (RNFL) thickness, macular ganglion cell complex (GCC), and retinal thickness in parafoveal and perifoveal regions were analyzed. RESULTS: No significant differences were observed in refraction, IOP, or corneal parameters among the three groups. OCT measurements showed that superior and inferior RNFL were significantly thinner in MPH-treated ADHD patients compared with controls (p = 0.010 and p < 0.001, respectively). Parafoveal retinal thickness, excluding the nasal quadrant, was increased in drug-naïve ADHD patients (superior p = 0.008, inferior p = 0.015, temporal p = 0.040), whereas perifoveal thickness was reduced in MPH-treated children (superior p = 0.011, inferior p = 0.014, temporal p = 0.004). No significant differences were found in GCC thickness between the groups. No significant correlation was observed between duration of MPH treatment and retinal thickness parameters (all p > 0.05). CONCLUSIONS: Anterior segment parameters were similar across groups, but retinal thickness differed between drug-naïve and MPH-treated ADHD patients, possibly related to disease characteristics or treatment effects, with no clear association with treatment duration. Prospective studies are needed to clarify these effects. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12886-026-04713-z.