Layer-Specific Corneal Densitometric Remodeling After Lasik, Clear, And Prk For Myopia ≤6.00 D: A Prospective Comparative Scheimpflug Analysis
Published 2026 - 44th Congress of the ESCRS
Reference: FP27.09 | Type: Free paper | DOI: 10.82333/3rza-gm82
Authors: Dr Renzo Pomatanta Diaz* 1 , Mr Rolando Rojas 1 , Mr Jose Chauca 2 , Dr Luis Izquierdo Jr 3 , Dr Maria A. Henriquez 1
1Research department,Oftalmosalud,Lima,Peru, 2Research department,Oftalmosalud,Lima,Peru;Department of Statistics, Demography, Humanities and Social Sciences,Universidad Peruana Cayetano Heredia,Lima,Peru, 3Research department,Oftalmosalud,Lima,Peru;San Fernando School of Medicine,Universidad Nacional Mayor de San Marcos,Lima,Peru
Purpose
To quantitatively compare layer-specific corneal densitometric changes after LASIK, CLEAR, and PRK in patients with myopia ≤6.00 D, and to determine whether different surgical mechanisms induce differential transparency alterations within the central optical zone.
Setting
Research Department at Oftalmosalud, Instituto de Ojos, Lima, Peru.
Methods
A prospective comparative study including 175 eyes undergoing refractive surgery: LASIK (n=87), CLEAR (n=60), and PRK (n=28). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalent were evaluated preoperatively and at 3 months postoperatively. Corneal densitometry (grayscale units, GSU) was obtained using Scheimpflug tomography (Pentacam HR), analyzing the anterior, central, posterior, and total stromal layers within concentric zones of 0–2, 2–6, 6–10, and 10–12 mm. Intra- and intergroup comparisons were performed using R statistical software, with significance set at p<0.05
Results
Postoperative spherical equivalent was −0.13±0.44 D (LASIK), −0.12±0.21 D (CLEAR), and −0.17±0.24 D (PRK), without intergroup differences (p=0.553). Anterior densitometry in the 0–6 mm zone differed significantly (global p<0.0001). In the 0–2 mm zone, values increased from 20.47±1.48 to 21.59±4.14 GSU (LASIK), 16.11±1.19 to 18.26±1.47 GSU (CLEAR), and 15.99±1.11 to 18.23±4.20 GSU (PRK). In the 2–6 mm zone, increases were greater after LASIK (14.69±0.78 to 19.15±3.08 GSU) compared with CLEAR (14.89±1.03 to 16.94±1.45) and PRK (14.72±0.89 to 15.61±3.17) (post-hoc p<0.0001). Total densitometry also increased in both zones, with significant intergroup differences (p<0.0001).
Conclusions
Significant differences were observed in anterior and total corneal densitometry within the central optical zone. LASIK induced the greatest increases in the 0–6 mm region, reflecting more pronounced anterior and overall stromal remodeling, whereas CLEAR showed the lowest densitometric impact.