Effect of epigallocatechin-gallate on inner retinal function in ocular hypertension and glaucoma: a short-term study by pattern electroretinogram.
BACKGROUND
Epigallocatechin-gallate (EGCG) is a powerful antioxidant with suggested neuroprotective action. The aim of this study was to evaluate the effect of short-term supplementation of EGCG on inner retinal function in ocular hypertension (OHT) and open-angle glaucoma (OAG).


METHODS
Eighteen OHT and 18 OAG patients (perimetric mean deviation: >-10 dB) were randomly assigned to assume oral placebo or EGCG over a 3-month period in a randomized, placebo-controlled, double-blind, cross-over design clinical trial (clinicaltrials.gov identifier: NCT00476138). Pattern-evoked electroretinograms (PERGs) to 1.6 cycles/degree square-wave gratings, counterphased at 16 reversals/second, and standard automated perimetry (Humphrey 30-2) were assessed at the study entry (baseline), and after 3 months of placebo or EGCG.


RESULTS
After EGCG, PERGs of OAG, but not OHT patients were increased in amplitude, compared either to baseline values (mean amplitude change: 0.06 log microV, p < 0.05) or to PERG amplitude values found in the same patients after placebo administration (mean change: -0.02 log microV, p not significant; difference between EGCG and placebo: 0.08 log microV, p < 0.05). In both OHT and OAG patients, standard automated perimetry did not show significant changes after either EGCG or placebo. In individual OAG patients, the magnitude of PERG amplitude increment after EGCG was inversely related (r = -0.8, p < 0.01) to corresponding baseline amplitudes.


CONCLUSIONS
Although this study cannot provide evidence for long-term benefit of EGCG supplementation in OAG, and the observed effect is small, the results suggest that EGCG might favourably influence inner retinal function in eyes with early to moderately advanced glaucomatous damage.
Falsini
Benedetto
B
Institute of Ophthalmology, Catholic University, Largo Francesco Vito 1, 00168 Rome, Italy. md0571@mclink.it
Marangoni
Dario
D
Salgarello
Tommaso
T
Stifano
Giovanna
G
Montrone
Lucrezia
L
Di Landro
Salvatore
S
Guccione
Laura
L
Balestrazzi
Emilio
E
Colotto
Alberto
A
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage*; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004596:Electroretinography; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy / Q000503:physiopathology; D010364:Pattern Recognition, Visual; D012165:Retinal Ganglion Cells / Q000502:physiology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
D000975:Antioxidants; D002392:Catechin; C045651:epigallocatechin gallate