Abstract
Purpose :
To evaluate the effect of meditation on oxygenation in the visual cortex using functional near infrared spectroscopy (fNIRS) in patients with primary open angle glaucoma (POAG).
Methods :
Forty POAG patients aged more than 45 years on topical ocular hypotensive therapy with best corrected visual acuity of 20/40 or better in both eyes were randomized into two groups. Twenty patients (Group I) underwent 60 minutes of mindfulness meditation focussed on breathing under a trained YOGA instructor for 21 days while 20 patients (Group II) were shortlisted for future meditation exercises and continued medical therapy. Patients with any co-morbid ocular or systemic diseases, performing yoga or meditation were excluded. Parameters evaluated included occipital cortex oxygenation by using functional near infrared spectroscopy, circumpapillary vessel perfusion (cpVP) on OCT Angiography (OCTa) and IOP. A 15-channel (s1 to s8, d1 to d7) fNIRS testing was done by using visual stimulation (Flicking checkerboard) to measure absolute changes in oxygenated (HbO) and deoxygenated (HbR) haemoglobin concentrations in the occipital cortices.
Results :
The mean age of the patients was 55.04± 7.23 and 57.11± 6.90 years in Group I and Group II respectively. (p= 0.47). Both groups had comparable baseline IOP (Group I: 17.16± 2.30 mmHg, Group II: 18.22± 3.65 mmHg, p= 0.39). In Group I, IOP decreased from 17.16± 2.30 to 13.30 ± 1.85 mmHg, p= 0.001; whereas no significant change was noted in Group II (18.22± 3.65 to 17.30± 1.44 mmHg, p= 0.63). In Group I, cpVP on OCTA increased from (.328± .054 to .515± .033) in superior, (.301± .042 to .483± .044) in nasal & (.228± .071 to .453± .057) in temporal quadrants (p= 0.001) in a 3mm scan; whereas no significant change in cpVP was noted in Group II (p= 0.49). On fNIRS, Group I showed a characteristic response of increased oxygenated haemoglobin (HbO) (Figure 1) and decreased deoxygenated haemoglobin (HbR) during visual stimulation presentation in occipital cortex, demonstrating a significant change in the functional cortical activity in occipital lobe after meditation [t >3.14, p=0.002]. However, no significant change was noted in Group II [t <1.12, p= 0.14].
Conclusions :
Meditation was associated with significant increase in occipital cortex oxygenation with better circumpapillary vessel perfusion and a decrease in IOP in POAG patients.
This is a 2020 ARVO Annual Meeting abstract.