When I was a resident we had limited options to treat allergic conjunctivitis. Now we have many more options.
As of 2016 options include:
1. Cold ice packs with cold nonprescription artificial tears
2. Crolomn sodium
3. Olopatadine: called Patanol or Pataday
4. Alcaftadine 0.25%: called Lastacaf
5. Nonsteroidal drops
6. Steroid drops: varying strengths
There remains few studies comparing the above options head to head. Below are a couple of studies I found thus far.
Still it is possible that a patient respond better to one class of drop than another. Thus the frustration of sometimes having to try different options may be needed. In addition I have had many patients say they have used an particular drop for years with effect only to not have it work any more. Is this tolerance in some patients? Possibly but we do not for sure why this happens in some and not in others.
Ocular Itch Relief with Alcaftadine 0.25% Versus Olopatadine 0.2% in Allergic Conjunctivitis: Pooled Analysis of Two Multicenter Randomized Clinical Trials
The efficacy and safety of the once-daily topical ophthalmic solutions, alcaftadine 0.25% and olopatadine 0.2%, in preventing ocular itching associated with allergic conjunctivitis were evaluated.
Methods
Pooled analysis was conducted of two double-masked, multicenter, active- and placebo-controlled studies using the conjunctival allergen challenge (CAC) model of allergic conjunctivitis. Subjects were randomized 1:1:1 to receive alcaftadine 0.25%, olopatadine 0.2%, or placebo. The primary efficacy measure was subject-evaluated mean ocular itching at 3 min post-CAC and 16 h after treatment instillation. Secondary measures included ocular itching at 5 and 7 min post-CAC. Ocular itch was determined over all time points measured (3, 5, and 7 min) post-CAC and the proportion of subjects with minimal itch (itch score <1) and zero itch (itch score = 0) was also assessed.
Results
A total of 284 subjects were enrolled in the two studies. At 3 min post-CAC and 16 h after treatment instillation, alcaftadine 0.25% achieved a significantly lower mean itch score compared with olopatadine 0.2% (0.50 vs. 0.87, respectively; P = 0.0006). Alcaftadine demonstrated a significantly lower mean itch score over all time points compared with olopatadine (0.68 vs. 0.92, respectively; P = 0.0390); both alcaftadine- and olopatadine-treated subjects achieved significantly lower overall mean ocular itching scores compared with placebo (2.10; P < 0.0001 for both actives). Minimal itch over all time points was reported by 76.1% of alcaftadine-treated subjects compared with 58.1% of olopatadine-treated subjects (P = 0.0121). Treatment with alcaftadine 0.25% and olopatadine 0.2% was safe and well tolerated; no serious adverse events were reported.
Conclusion
Once-daily alcaftadine 0.25% ophthalmic solution demonstrated greater efficacy in prevention of ocular itching compared with olopatadine 0.2% at 3 min post-CAC (primary endpoint), and over all time points, 16 h post-treatment instillation. Alcaftadine and olopatadine both provided effective relief compared with placebo and were generally well tolerated.
