Dose-dependent immunohistochemical changes in rat cornea and retina after oral methylphenidate administration

A systematic review and meta-analysis on the ocular characteristics in children and adolescents with neurodevelopmental disorders

To conduct a systematic review and meta-analysis of the association between children and adolescents with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) and ocular characteristics. Systematic review with meta-analysis. Six databases (PubMed, Scopus, APA PsycInfo, Embase, EBSCOhost, and Cochrane library) were selected for a systematic literature search from database inception to July 2022. The observational studies assessing and reporting at least one outcome regarding ocular characteristics in children and adolescents with ADHD or ASD aged 6-17 were included. Studies in languages other than English, studies of adult or elderly human populations, and animal studies were excluded. The results were analyzed following the PRISMA guideline 2020. The findings of 15 studies, including 433 participants with ADHD, 253 participants with ASD, and 514 participants with typical development (TD), revealed that there were no significant differences in retinal nerve fiber layer, ganglion cell complex, and macular thickness between the ADHD group and the TD group. In subgroup analysis, significant differences in inferior ganglion cell (MD = - 3.19; 95% CI = [- 6.06, - 0.31], p = 0.03) and nasal macular thickness (MD = 5.88; 95% CI = [- 0.01, 11.76], p = 0.05) were detected between the ADHD group and the TD group. A significant difference in pupillary light reflex (PLR) was also observed between the ASD group and the TD group (MD = 29.7; 95% CI = [18.79, 40.63], p < 0.001). Existing evidence suggests a possible association between children and adolescents with ADHD or ASD and ocular characteristics. Given the limited number of studies, further research on a larger cohort is necessary to claim a possible diagnosis of ADHD or ASD through ocular characteristics.

Choroidal Vascular Index in Patients With Attention-Deficit/Hyperactivity Disorder and Methylphenidate

PURPOSE

To investigate choroidal vascularity in children with attention-deficit/hyperactivity disorder (ADHD) who were not receiving therapy, children with ADHD who were regularly taking methylphenidate (MPH), and healthy controls.

METHODS

The study included three groups: patients with newly diagnosed ADHD without treatment, patients diagnosed as having ADHD who were already being treated with oral MPH, and controls. Both choroidal vascularity index (CVI) and choroidal thickness were measured using an enhanced-depth imaging mode of spectral-domain optical coherence tomography (EDIOCT) (Spectralis; Heidelberg Engineering GmbH).

RESULTS

There was a significant difference in CVI and stromal area between groups. Post-hoc univariate analysis showed that CVI was significantly lower in patients with ADHD treated with MPH compared with the other groups (P < .001, for each); however, there was no difference between the treatment-free ADHD group and controls (P = .305). In contrast, stromal area was significantly higher in patients with ADHD treated with MPH than the other groups (P < .001, for each group). The correlation of CVI with MPH treatment duration in patients with ADHD treated with MPH showed a significant, moderate negative correlation (P = .01, r = - 0.66).

CONCLUSIONS

CVI is reduced in patients with ADHD treated with MPH, and the decrease in CVI becomes significant with increasing duration of MPH treatment. This result reflects an indirect effect of MPH treatment on choroidal vascular structures. [J Pediatr Ophthalmol Strabismus. 2023;60(6):411-416.].

Methylphenidate causes cytotoxicity on photoreceptor cells via autophagy

Methylphenidate (MPH) is used as the first-line treatment for attention-deficit hyperactivity disorder. However, there are concerns that this treatment may be associated with increased risk of retinal damage. This study was to investigate cytotoxicity of MPH on photoreceptor cells and explore its underlying mechanisms. MPH-caused cell toxicity was established in 661 W cells. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium-bromid and lactate dehydrogenase assays. Oxidative stress was measured by the markers: glutathione (GSH) reductase, catalase, and superoxide dismutase activities as well as GSH, reactive oxygen species, and malondialdehyde levels. Gene and protein expression was detected by real-time polymerase chain reaction (PCR) and western blot, respectively. Results showed that MPH decreased 661 W cell viability, increased caspase-3/9 activities, and induced oxidative stress. Furthermore, MPH treatment increased messenger RNA (mRNA) expression of Beclin-1 and microtubule-associated protein 1A/1B-light chain 3B (LC3B) protein expression in 661 W cells, suggesting autophagy was induced. MPH treatment also upregulated p-JAK1/p-STAT1 protein expression. These data demonstrated that MPH could increase oxidative stress in photoreceptor cells to cause cell toxicity via autophagy, providing the scientific rationale for the photoreceptor cell damage caused by the MPH administration.

Foveal avascular zone and vessel density in children with attention deficit hyperactivity disorder

PURPOSE

To compare the retinal and choroidal microvasculature quantitatively via optical coherence angiography (OCTA) in children with attention deficit hyperactivity disorder (ADHD) who were under methylphenidate (MFD) treatment or newly diagnosed as ADHD and were not taking any medication.

METHODS

This was a cross-sectional, comparative, and observational study. The children who were between 6 and 17 years old and previously diagnosed as ADHD and were under MFD treatment or who were newly diagnosed as ADHD were included in the study. Optical coherence tomography angiography imaging was performed via OCT RT XR Avanti with AngioVue software (Optivue Inc, Freemont, CA). The main outcome measure of the study was OCTA parameters of the children with ADHD.

RESULTS

A total of 186 eyes of 186 patients were included in the study. There were 80 eyes in the control group (newly diagnosed) and 106 eyes in the treatment group (under MFD treatment). The mean duration of methylphenidate use in the treatment group was 33.9 ± 20.1 months (between 6 and 84 months). The choriocapillary flow area (p = 0.03), superficial parafoveal thickness (p = 0.01), and deep parafoveal thickness (p = 0.01) were statistically greater in the treatment group than the control group.

CONCLUSION

Most of the important OCTA parameters especially foveal avascular zone (FAZ) area and FAZ perimeter were similar in the two groups. There was a significant difference between the two groups in parafoveal thickness values which might point to a slight effect of MFD on retinal circulation.