Randomized observer-masked single-center trial (N=180, 60 per arm): mean total ocular symptom score fell from 7.7 at baseline to 0.2 at day 14 with alcaftadine, versus 0.4 with olopatadine 0.2% and 0.1 with bepotastine 1.5% (day 14 ANOVA P=0.0008); absolute separation between the three actives was small. Contact lens wearers and severe allergic conjunctivitis were excluded.

Randomized 22-center trial in perennial allergic conjunctivitis (N=139) against masked placebo, with an open-label levocabastine arm: itching and conjunctival redness both improved versus placebo (P<0.001), the combined score improving 1.9 (SD 1.1) versus 0.6 (SD 1.1) on placebo at day 7 from a baseline of 3.7 to 3.8 on a 0 to 6 scale, and continuing to improve through day 42. Bitter taste and application site reaction were the most frequent adverse events. The US indication covers itching only, not redness.

Single center open label comparative trial in 50 patients with vernal keratoconjunctivitis, aged 5 to 15, allocated to 1.5% solution or olopatadine 0.1% BID for 8 weeks. The authors report quicker relief of watering, ocular discomfort, and conjunctival hyperemia in the bepotastine arm but state the difference was not statistically significant; olopatadine improved papillary hypertrophy faster, and the two were equal for itching.

Cochrane review of 30 randomized trials and 4344 participants concluded that topical antihistamines and mast cell stabilizers as a class, sodium cromoglycate among the drugs evaluated, reduce symptoms and signs of seasonal allergic conjunctivitis versus placebo in the short term, with no long term efficacy data and highly variable reporting quality. A comparative review of the seasonal trials notes that cromoglycate eye drops did not control breakthrough symptoms during peak pollen challenge.

Pooled analysis of SICCANOVE and SANSIKA, two double-masked randomized vehicle-controlled phase 3 trials of 0.1% cyclosporine A cationic emulsion dosed once daily for 6 months in adults (395 on drug, 339 on vehicle): treated patients were more likely to be composite corneal staining plus OSDI responders at month 6, odds ratio 1.66 (95% CI 1.11 to 2.50, P = 0.015), holding in severe dry eye (OR 1.80, 95% CI 1.04 to 3.19, P = 0.038) and in Sjogren's syndrome with severe dry eye (OR 3.37, 95% CI 1.20 to 11.19, P = 0.030) but not in the overall Sjogren's population (OR 1.77, 95% CI 0.89 to 3.66, P = 0.109). Conjunctival HLA-DR expression fell versus vehicle (P = 0.002). Note the mismatch with this label: those trials dosed once daily in adults with dry eye, not QID for vernal disease, and dry eye is not a US-approved indication for this product.

Randomized, open-label, multicenter trial during allergy season (N=146, 75 treated vs 71 on rewetting drops alone): mean comfortable wearing time rose 1.33 h vs 0.43 h (P=0.012) and total wearing time 0.35 h vs -0.32 h (P=0.008), with greater improvement in itch and overall comfort and fewer rewetting drop instillations. Read alongside the label, which states the product is not for contact lens-related irritation and that lenses come out before instillation.

Prospective, non-comparative series of 67 eyes in 34 patients on a mean 15.3 months of therapy: 82.0% of eyes reached control of inflammation at a mean of 2.2 months, signs improved significantly by month 3 (p<0.05), 35.8% reached remission, 18.0% relapsed on therapy, and 7.4% failed. No control arm and concomitant pulsed steroid, so the effect cannot be attributed to lodoxamide alone; it supports it as a steroid-sparing maintenance option, not as proven monotherapy.

Randomized, double-masked, seven-center trial in 93 patients with seasonal or perennial allergic conjunctivitis, QID against levocabastine 0.05% BID: both arms produced statistically and clinically significant reductions from baseline in symptom and sign scores by days 7 and 14 with no difference between groups. After the first instillation, however, signs were relieved faster in the levocabastine arm (p<0.001), which is the practical argument for reaching for an antihistamine when a patient needs same-day relief. No placebo arm.

Investigator single-masked randomized trial in children aged 4 to 17 with mostly limbal disease, 18 per arm and 34 completing, against sodium cromoglycate 2% QID for 5 months. Effect came on faster, with significant separation for itching, grittiness, hyperemia, and keratitis by 6 weeks and superiority for hyperemia, keratitis, papillae, and pannus at 22 weeks; full control was recorded for 94% by patient opinion and 100% by clinician opinion versus 29% and 0% on cromoglycate. Weak design: small, no placebo arm, single-masked, and rescue dexamethasone was permitted.

Pooled statistical overview of the manufacturer's double-masked placebo-controlled program: in perennial disease QID (n=146) outperformed BID (n=86), and QID controlled 72% of patients versus 47% on placebo (n=156, p<0.001), while BID was adequate for seasonal disease. Evidence is a sponsor overview of pooled European trials of the same 2% solution, not an independent randomized trial, so treat the QID escalation as reasonable rather than proven.