Additional Table 3.

Summary of the effects of omega-3 and vitamin B3 on glymphatic activity and the visual system

Type of supplement	Specific supplement(s)	Exp. Type	Model/Species	Dosage and Admin. Route	Exp. Protocols	Main findings	Citation
Omega-3	Safflower, flaxseed, and tuna oils	in vivo	Sprague- Dawley rats	° ω-3−: 7% saff. oil ° ω-3+: 5.5% saff., 1.00% flax., 0.50% tuna oils ° Oral	° IOP measured at 5, 10, 20, 40 wk of age	° 20+ wk old mice: ↓ IOP more in ω-3+ group than ω-3− group ° May be correlated with decreased aqueous outflow facility in the ω-3− group	Nguyen et al. (2007)
	DHA	in vivo	fat-1, C57BL/6J, Aqp4-/-mice	° 30 mg/kg ° Fish oil with 52.4% DHA ° Oral	° Daily oral gavage for 3 wk °Intracisternal infusion of FITC-d3 tracer to track CSF movement	° fat-1: ↑ endogenous n-3 PUFA levels ∝ faster and more efficient Aβ clearance, ↓ impairment of hippocampus-dependent memory and AQP4 polarization post-Aβ ICV injection ° C57BL/6J: ↑ CSF influx and clearance, hippocampus CA3 region neuron survival, spatial learning and memory ° Aqp4-/-: confirmed involvement of AQP4 channels in PUFA promoting CSF clearance	Ren et al. (2017)
		in vivo	Humans	° 1050 mg/d ° Oral	° 6 mon treatment ° Evaluated at baseline, 3 and 6 mon	↓ IOP by 2-3 mmHg in both eyes in treatment group ↑ DHA content in erythrocyte membrane, TAC, MDA, plasma IL-6 levels	Romeo Villadóniga et al. (2018)
	DHA, EPA	in vivo	APP/PS1, C57BL/6J mice	° 50 μL of fish oil (13 μM EPA, 99 μM DHA) ° Intragastrical	° daily for 4 wk	TAC, MDA, plasma IL-6 levels ↑ Aβ1-40 levels in plasma ∝↑ Aβ transport from brain by transport proteins ↓ Overactivation of astrocytes and microglia by inhibiting NF-κB phosphorylation	Yan et al. (2020)
	DHA, EPA, ALA	in vivo	Humans	° 500-600 mg DHA, 1000 mg EPA, +/-900 mg ALA daily ° Oral	° 90 d treatment ° IOP measured at baseline and day 90	↓ IOP by at least 8% in non-glaucomatous adults consuming typical Western diet with ω-3 supplementation	Downie and Vingrys (2018)
	DHA, EPA,	in vivo	Sprague-	° 10% EPA + 7%	° 6 mon treatment	↑ IOP increase post-laser treatment	Schnebelen et al. (2009)
	GLA		Dawley rats	DHA ° 10% GLA or ° 10% EPA + 7% DHA + 10% GLA ° Oral	° IOP elevation at 3 mon via laser photocoagulation of episcleral veins, limbus, and TM ° IOP measured weekly	° PUFA supplementation did not affect rate of IOP change post-op, did not prevent loss of RGCs or retinal function ° EPA+DHA+GLA: ↓ glial cell activation and ↑ retinal cells preservation ∝↓ retinal stress post-photocoagulation
	DHA, EPA, timolol	in vivo	DBA/2J, C57BL/6J mice	° 270 mg/g/d (400 mg EPA + 200 mg DHA) ° 0.5% timolol ° Oral and/or topical	° Daily treatment for 3 mon total ° Disease progression monitored via tonometry and slit lamp biomicroscopy	° PUFA+timolol: preserved RGC density but no effect on retinal microglial activation ° PUFA or timolol: ↓ expression of retinal pro-inflammatory cytokines and M1/M2 macrophages ° timolol only: ↓ IOP	Kalogerou et al. (2018)
Vitamin B3	NAM	in vivo, in vitro	DBA/2J mice	° 550 or 2000 mg/kg ° Oral	° Received NAM treatment at 6 mon old (pre-IOP elevation) or at 9 mon old (post-IOP elevation)	↓ ON degeneration, RGC soma loss, RNFL thinning ↑ Protection of visual and metabolic functions ↓ Age-related gene expression changes in RGCs ° Higher dosage led to no ON damage in 93% of treated eyes and less IOP elevation	Williams et al. (2017)
		in vivo, in vitro	DBA/2J mice	° 550 mg/kg/d ° Oral	° NAM added to drinking water	° Resulted in protection from synapse and RGC loss, RGC activity declines, anterograde axon transport and decreased incidences of remodeling and atrophy of ONH	Williams et al. (2018)
		in vivo	Humans diagnosed with glaucoma	° 1.5 g/d, then 3.0 g/d ° Oral	° 6 wk of each dosage, then crossover without washout	° Significant improvement in inner retinal function in high dosage most likely via metabolic rescue of RGCs ° No significant changes in IOP or RNFL thickness	Hui et al. (2020)
		in vivo	DBA/2J mice	° 200 mg/kg/d Oral	° Chow/water enriched with NAM ° Mice monitored from 3 to 12 mon old ° PERG with flickering field to assess RGC autoregulation	↑ Preservation of RGC function ↓ IOP ° At least 2x more preservation of RGCs and mitochondria than in control mice	Chou et al. (2020)

Aβ: Amyloid-beta; ALA: α-linolenic acid; AQP4: aquaporin-4; CSF: cerebrospinal fluid; DHA: docosahexaenoic acid; EPA: eicosapentaenoic acid; FITC: fluorescein isothiocyanate; GLA: γ-linolenic acid; ICV: intracerebroventricular; IL: interleukin; IOP: intraocular pressure; MDA: (plasma) malondialdehyde; NAM: nicotinamide; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; ω-3: omega-3; ON: optic nerve; ONH: optic nerve head; PERG: pattern electroretinogram; PUFA: polyunsaturated fatty acids; RGC: retinal ganglion cells; RNFL: retinal nerve fiber layer; TAC: total antioxidant capacity; TM: trabecular meshwork.