Relevance: To determine whether red-spectrum photodynamic therapy (PDT) with methylene blue, alone or combined with the antioxidant drop Vixipin, accelerates epithelial regeneration after chemical eye burns, quantified by cytomorphometry. Methods: In a prospective clinical study (2019–2021), 110 patients (155 eyes) with grade I–III chemical burns were assigned to: conventional therapy (comparison), conventional therapy + PDT (630 nm), or conventional therapy + PDT + Vixipin. Impression cytology of the cornea/conjunctiva was analyzed with ImageJ to measure nuclear and cytoplasmic areas; the nuclear-to-cytoplasmic ratio (NCR = nucleus area / cytoplasm area) was the primary endpoint. Outcomes were assessed at baseline and day 7. Group differences and within-group changes were tested at α=0.05. Results: Baseline cytomorphometry was comparable across groups. By day 7, epithelial cytoplasm area decreased markedly, indicating maturation: ≈2.2× in the comparison group, ≈4.3× with PDT, and ≈5.0× with PDT + Vixipin. Nuclear area remained relatively stable across groups. Consequently, NCR rose significantly: from 0.069±0.016 to 0.146±0.039 (↑2.12×) in the comparison group, from 0.077±0.018 to 0.296±0.067 (↑3.84×) with PDT, and from 0.066±0.016 to 0.319±0.063 (↑4.83×) with PDT + Vixipin (all p<0.05), with both active arms superior to comparison and the combination superior to PDT alone. Conclusions: Red-laser PDT enhances early epithelial recovery after chemical ocular burns, and adjunctive Vixipin further augments this effect. The significant rise in NCR with concurrent cytoplasmic shrinkage supports faster epithelial renewal under the combined regimen, suggesting a practical, reproducible adjunct to standard care.

Chemical eye burn, laser radiation, photodynamic therapy, Vixipin

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