Corneal densitometry changes after femtosecond laser-assisted intracorneal ring segments implantation in keratoconus.

Autor:	Mounir A; Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt., Mohamed Mostafa E; Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt., Amer I; Ophthalmology Department, Faculty of Medicine, Assiut branch, Al-Azhar University, Assiut, Egypt., Abdelgbar AA; Ophthalmology Department, Faculty of Medicine, Assiut branch, Al-Azhar University, Assiut, Egypt., Osman HO; Ophthalmology Department, Faculty of Medicine, Assiut branch, Al-Azhar University, Assiut, Egypt., Ahmed MA; Ophthalmology Department, Faculty of Medicine, Assiut branch, Al-Azhar University, Assiut, Egypt., Ziada H; Ophthalmology Department, Faculty of Medicine, Cairo branch, Al-Azhar University, Cairo, Egypt., Ali El Gabbar AG; Ophthalmology Department, Faculty of Medicine, Cairo branch, Al-Azhar University, Cairo, Egypt., Hassan MA; Ophthalmology Department, Faculty of Medicine, Cairo branch, Al-Azhar University, Cairo, Egypt., Mahmoud A; Ophthalmology Department, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt.
Jazyk:	angličtina
Zdroj:	Medical hypothesis, discovery & innovation ophthalmology journal [Med Hypothesis Discov Innov Ophthalmol] 2024 Jul 01; Vol. 13 (1), pp. 27-34. Date of Electronic Publication: 2024 Jul 01 (Print Publication: 2024).
DOI:	10.51329/mehdiophthal1491
Abstrakt:	Background: Intrastromal corneal ring segments are commonly implanted in the corneas of eyes with mild-to-moderate keratoconus; however, changes in corneal densitometry (CD) after implantation are a matter of debate in the current literature. We evaluated the changes in CD 1 and 3 months after femtosecond laser-assisted Keraring implantation. Methods: This retrospective, non-comparative, multicenter, case series study included patients with keratoconus who underwent femtosecond laser-assisted implantation of double segments with 90° and 160° arc lengths or two 160° arc length Keraring segments. Demographic and baseline clinical ophthalmic data were recorded. Corneal topography and tomography data acquired using a Pentacam HR Scheimpflug tomography system (Pentacam High Resolution; Oculus, Wetzlar, Germany) with a best-fit sphere were used as a reference surface. Using the Pentacam HR, CD measurements were acquired over a corneal area of 12 mm in total and at four concentric zones (0-2, 2-6, 6-10, and 10-12 mm) of three corneal stromal depths: 120 μm of the anterior corneal stromal layer, 60 μm of the posterior corneal stromal layer, and the central layer of stroma lying between these two layers. Results: We included 40 eyes of 40 patients, including 8 (20%) male and 32 (80%) female individuals, with a mean (standard deviation) age of 21.0 (6.4) years. We observed a significant improvement in the topographic values of steep keratometry (K), flat K, maximum K, and corneal astigmatism (all P < 0.05), but not in the mean K, thinnest corneal pachymetry, corneal thickness at the apex, back elevation, or front elevation (all P > 0.05). The mean total anterior, central, and posterior CD differed significantly among the time points, with a significant increase from the preoperative to the 1-month and 3-month postoperative visits (all P < 0.05) and no difference between those of the 1-month and 3-month postoperative visits (all P > 0.05). The mean CD for the anterior layer in the central, paracentral, and mid-peripheral zones, and the central layer in all four zones, differed significantly among time points, with a significant increase from the preoperative to the 1-month and 3-month postoperative visits (all P < 0.05), which remained unchanged from the 1-month to the 3-month postoperative visit (all P < 0.05), except for the central 2-6-mm zone, which decreased significantly from the 1-month to the 3-month postoperative visit (P < 0.001). The CD of the central 10-12-mm zone did not differ significantly in each pairwise comparison (all P > 0.05). In contrast, CD for the posterior layer in the paracentral zone decreased significantly from the preoperative to the 1-month and 3-month postoperative visits but increased, to a lesser extent, from the 1-month to the 3-month postoperative visit (all P < 0.05). Conclusions: Femtosecond laser-assisted Keraring implantation significantly changes CD, with improvement in most topography parameters. Further longitudinal studies with larger sample sizes are required to verify these preliminary findings. Competing Interests: None. (© Author(s).)
Databáze:	MEDLINE
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