Phase of Neovascularization in Wound Repair: Topical Impact of Low-Level Laser Therapy with Conventional Treatment in Rabbit Model

Abstract

Background: Neovascularization is the rate-limiting event in the proliferative phase of wound repair, and its accelerated induction represents a key therapeutic target in surgical wound management. Low-level laser therapy (LLLT), a non-invasive photobiomodulatory modality, has demonstrated pro-angiogenic properties through cytochrome c oxidase-mediated bioenergetic stimulation and growth factor upregulation, yet direct histomorphometric comparisons with conventional topical agents such as normal saline and Edinburgh University Solution of Lime (Eusol) remain insufficiently characterised. Objective: To evaluate and compare the effect of topical LLLT, normal saline, and Eusol dressing on the neovascularization phase of full-thickness surgical wound repair using quantitative vascular density assessment across discrete healing time points in an experimental rabbit model. Methods: Fifteen male albino rabbits (200–350 g) were randomly allocated to three groups (n = 5/group): Group A (normal saline, daily), Group B (LLLT, 10 J/cm², 830 nm, THOR DD II device, daily), and Group C (Eusol dressing, daily). Full-thickness excisional wounds (2.5 × 2.5 cm²) were created on the dorsal surface under ketamine–xylazine anaesthesia. Wound tissue biopsies were collected at Days 3, 7, and 14, processed for haematoxylin and eosin staining, and mean vascular counts were enumerated per 0.196 mm² field at 400× magnification by a blinded histologist. Data were analysed using one-way ANOVA with post hoc Tukey's HSD test (p < 0.05). Results: Group B demonstrated significantly superior mean vascular counts at all time points: Day 3 (6.65 ± 1.80 versus 2.31 ± 1.20 and 3.54 ± 0.41), Day 7 (10.47 ± 0.11 versus 3.21 ± 0.32 and 5.68 ± 1.74), and Day 14 (8.88 ± 0.63 versus 4.45 ± 0.71 and 5.97 ± 1.57) for Groups A and C respectively (p = 0.040–0.001; η² = 0.721–0.916). A biphasic trajectory with peak neovascularization at Day 7 was observed exclusively in Group B. Conclusion: LLLT significantly accelerates surgical wound neovascularization compared with normal saline and Eusol, supporting its integration as an adjunctive modality in evidence-based wound management protocols.