Abstract
Purpose:
To evaluate the effects on contrast sensitivity (cs) measurements of panretinal photocoagulation (prp) associated with intravitreal ranibizumab (rbz) injections versus prp alone in non-high risk treatment-naïve proliferative diabetic retinopathy (pdr) eyes.
Methods:
Fifty eyes of 25 patients with bilateral pdr were randomised to two groups: one randomly selected eye underwent prp and rbz injections (study group, sg) and the other prp alone (control group, cg). All eyes were treated with prp administered in three sessions according to etdrs guidelines. Intravitreal rbz injections (sg) or sham injections (cg) were given at weeks 1 and 4. Cs measurements were performed under photopic conditions (85cd/m2) with the vcts 6500 chart (vistech consultants incorporation, dayton, ohio, usa) positioned 3 m away, allowing for evaluation of five spatial frequencies with sine wave grating charts: 1.5, 3.0, 6.0, 12.0 and 18.0 cycles per degree (cpd).main outcome measures: mean change in cs threshold scores amongst and within groups, from baseline to 1, 3 and 6 months.
Results:
Forty eyes (22 sg and 18 cg) were evaluated, as they had no hemorrhage at any visit. Mean cs threshold in between the two groups showed no significant differences (p>0.05) except at month 1 at 3.0 cpd. Cg had significant worsening (p<0.05) of cs at 3.0 cpd after 1 month. Sg had no significant change. A trend towards worsening for the cg and improvement for the sg at 1.5 and 18.0 cpd, worsening at month 1 but improvement at months 3 and 6 in cg but improvement from month 1 onwards in sg at 6.0 and 12.0, and worsening in both groups at 3.0 cpd was noted.
Conclusions:
In eyes with non-high risk-pdr, prp treatment is associated with early worsening of cs while adjuvant use of rbz prevents such deterioration. Cs evaluation seems to support the adjuvant use of rbz when using prp for the treatment of pdr.
Keywords: 499 diabetic retinopathy •
478 contrast sensitivity •
578 laser