18683
document
Further evaluation of docosahexaenoic acid in patients with retinitis pigmentosa receiving vitamin A treatment : subgroup analyses . OBJECTIVE To determine whether docosahexaenoic acid will slow the course of retinal degeneration in subgroups of patients with retinitis pigmentosa who are receiving vitamin A . DESIGN A cohort of 208 patients with retinitis pigmentosa , aged 18 to 55 years , were randomly assigned to 1200 mg of docosahexaenoic acid plus 15 000 IU/d of vitamin A given as retinyl palmitate ( DHA + A group ) or control fatty acid plus 15 000 IU/d of vitamin A ( control + A group ) and followed up over 4 years . Seventy percent of the patients in each group were taking vitamin A , 15 000 IU/d , prior to entry . We compared rates of decline in ocular function in the DHA + A vs control + A groups among the subgroups defined by use or nonuse of vitamin A prior to entry . We also determined whether decline in ocular function was related to red blood cell phosphatidylethanolamine docosahexaenoic acid level , dietary omega-3 fatty acid intake , or duration of vitamin A use . Main outcome measures were Humphrey Field Analyzer visual field sensitivity , 30-Hz electroretinogram amplitude , and visual acuity . RESULTS Among patients not taking vitamin A prior to entry , those in the DHA + A group had a slower decline in field sensitivity and electroretinogram amplitude than those in the control + A group over the first 2 years ( P =.01 and P =.03 , respectively ) ; these differences were not observed in years 3 and 4 of follow-up or among patients taking vitamin A prior to entry . In the entire cohort , red blood cell phosphatidylethanolamine docosahexaenoic acid level was inversely related to rate of decline in total field sensitivity over 4 years ( test for trend , P =.05 ) . This was particularly evident over the first 2 years among those not on vitamin A prior to entry ( test for trend , P =.003 ) . In the entire control + A group , dietary omega-3 fatty acid intake was inversely related to loss of total field sensitivity over 4 years ( intake , < 0.20 vs > or =0.20 g/d ; P =.02 ) . The duration of vitamin A supplementation prior to entry was inversely related to rate of decline in electroretinogram amplitude ( P =.008 ) . CONCLUSIONS For patients with retinitis pigmentosa beginning vitamin A therapy , addition of docosahexaenoic acid , 1200 mg/d , slowed the course of disease for 2 years . Among patients on vitamin A for at least 2 years , a diet rich in omega-3 fatty acids ( > or =0.20 g/d ) slowed the decline in visual field sensitivity .
18684
Intervention_Pharmacological
docosahexaenoic acid
18685
Intervention_Pharmacological
vitamin A
18686
Intervention_Pharmacological
docosahexaenoic acid
18687
Intervention_Pharmacological
vitamin A
18688
Intervention_Pharmacological
docosahexaenoic acid plus 15 000 IU/d of vitamin A given as retinyl palmitate ( DHA + A group )
18689
Intervention_Control
control fatty acid plus 15 000 IU/d of vitamin A ( control + A group )
18690
Intervention_Pharmacological
vitamin A
18691
Intervention_Pharmacological
DHA + A
18692
Intervention_Pharmacological
control + A
18693
Intervention_Pharmacological
vitamin A
18694
Intervention_Psychological
not taking vitamin A
18695
Intervention_Pharmacological
DHA + A
18696
Intervention_Pharmacological
control + A
18697
Intervention_Pharmacological
vitamin A
18698
Intervention_Pharmacological
docosahexaenoic acid
18699
Intervention_Pharmacological
not on vitamin A
18700
Intervention_Pharmacological
dietary omega-3 fatty acid
18701
Intervention_Pharmacological
vitamin A supplementation
18702
Intervention_Physical
vitamin A therapy
18703
Intervention_Pharmacological
docosahexaenoic acid
18704
Intervention_Pharmacological
vitamin A
18705
Intervention_Pharmacological
omega-3 fatty acids
18706
Outcome_Physical
Humphrey Field Analyzer visual field sensitivity
18707
Outcome_Other
30-Hz electroretinogram amplitude
18708
Outcome_Physical
visual acuity
18709
Outcome_Physical
field sensitivity
18710
Outcome_Other
electroretinogram amplitude
18711
Outcome_Physical
total field sensitivity
18712
Outcome_Physical
total field sensitivity
18713
Outcome_Physical
duration of vitamin A supplementation
18714
Participant_Condition
retinitis pigmentosa
18715
Participant_Condition
retinitis pigmentosa
18716
Participant_Sample-size
208
18717
Participant_Condition
retinitis pigmentosa
18718
Participant_Age
18 to 55 years
18719
Participant_Condition
retinitis pigmentosa