Purpose : To study the immediate effect of Lycium barbarum (LB) treatment on retinal functions, especially the cone function, in patients with retinitis pigmentosa (RP).
Methods : The study is a double-masked randomized clinical trial. RP subjects were recruited with eye examination including ETDRS Visual Acuity, Humphrey Field Analysis and Multifocal Electroretinogram. The RP subjects were randomly allocated to either LB or placebo groups with daily treatment (10g/day) for 12 months and had follow up in every 6 months.
Results : It is the report after the first 6 months of intervention. There were 23 subjects in LB group (49.8±13.3yr) and 12 in placebo group (46.5±10.2yr); p=0.43). The compliance rates for LB and placebo groups were 89±8.2% and 85±11.1% respectively (p=0.30).
The changes of 90% contrast VA for LB and placebo groups were -0.01±0.05 and 0.07±0.12 respectively (p=0.09). The changes of 10% contrast VA for LB and placebo groups were -0.05±0.08 and 0.06±0.07 respectively which were significantly different (p=0.047). The changes of mean defect from HFA 30-2 full-threshold for LB and placebo groups were -0.33±0.80dB and -0.06±0.63dB respectively (p=0.50). The changes of mean defect from HFA 10-2 full-threshold for LB and placebo groups were -0.13±1.10dB and -1.40±1.25dB respectively which were significantly different (p=0.04).
The amplitude changes of direct component (DC) from global flash mfERG for LB and placebo groups were: -2.44±4.25nV/°2 (Central, C); -0.14±1.13nV/°2 (Paracentral, P) and 2.01±8.52nV/°2 (C); 0.03±0.83nV/°2 (P) respectively. The amplitude changes of induced component (IC) from mfERG for LB and placebo groups were -5.28±12.2nV/°2 (C); -0.23±1.30nV/°2 (P) and -0.73±4.71nV/°2 (C); -0.33±0.58nV/°2 (P) respectively. The implicit time changes of DC for LB and placebo groups were: 0.73±3.07msec (C); 0.64±4.71msec (P) and 1.55±4.28 msec (C); -0.35±2.51msec (P) respectively. The implicit time changes of IC for LB and placebo groups were: 1.41±2.52msec (C); 1.21±5.42msec (P) and 0.42±4.81msec (C); -0.52±4.82msec (P) respectively. No significance were observed in all mfERG parameters (p>0.05).
Conclusions : Our results confirm that the 6 months LB treatment for RP patients had marginal significant improvement in low-contrast VA and central visual sensitivity. The neuroprotective effect of LB is believed to delay or minimize the deterioration of central visual function in RP.
|Conference||Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting 2016|
|Period||1/05/16 → 5/05/16|