Clinical Retinal Image Quality of a Non-diffractive Wavefront-Shaping Extended Depth of Focus (Vivity) Intraocular Lens.

PURPOSE: To evaluate clinical retinal optical image quality following implantation of an extended depth of focus intraocular lens (EDOF IOL) (Vivity; Alcon Laboratories, Inc), and to compare it with a monofocal and a trifocal IOL. METHODS: This prospective, comparative, case-control study included 88 eyes implanted with: (1) 19 monofocal IOLs (AcrySof SA60AT; Alcon Laboratories, Inc); (2) 38 EDOF IOLs (AcrySof IQ Vivity); and (3) 31 trifocal IOLs (AT LISA tri 839MP; Carl Zeiss Meditec AG). Total root mean square, ocular lower (LOA) and higher (HOA) order aberrations, point spread function (PSF) Strehl ratio (PSF with LOA), and PSF Strehl ratio excluding LOA (PSF without LOA) were analyzed using a Pyramidal WaveFront-based sensor aberrometer Osiris (Costruzione Strumenti Oftalmici) at two different pupil sizes (3 and 4 mm). RESULTS: The trifocal IOL showed the highest PSF without LOA at both pupil sizes (0.52 ± 0.12 and 0.31 ± 0.07, respectively), followed by the AcrySof SA60AT (0.39 ± 0.10 and 0.27 ± 0.07) and AcrySof IQ Vivity (0.34 ± 0.11 and 0.24 ± 0.09) (P < .001). The AcrySof IQ Vivity and monofocal IOLs were comparable (P > .05). Despite the comparable postoperative low spherical equivalent among the IOL groups, the AT LISA tri 839MP retinal image quality (PSF with LOA) was the most severely affected by such residual refractive errors (dropped to 0.26 ± 0.06 at 3 mm; P < .001) compared to the monofocal AcrySof SA60AT (0.24 ± 0.07 at 3 mm) and EDOF Acrysof IQ Vivity (0.23 ± 0.06 at 3 mm) groups. The PSF with LOA was comparable (P > .05) among the three groups at both the 3-and 4-mm pupil size. CONCLUSIONS: Although trifocal IOLs provided significantly better retinal image quality if influence of LOA is excluded, they also demonstrated to be the most sensitive to residual refractive errors. Both the EDOF Acrysof IQ Vivity and mono-focal AcrySof SA60AT IOLs showed a comparable retinal image quality, and they are also comparable with trifocal IOLs when considering the clinically real PSF (PSF with LOA). [J Refract Surg. 2023;39(2):103-110.].

Corneal Epithelium Thickness and Refractive Changes After Myopic Laser Corneal Refractive Surgery.

PURPOSE: To evaluate the postoperative changes in corneal epithelium thickness and refractive power after femtosecond laser-assisted laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE) for myopia correction using anterior segment optical coherence tomography (OCT) with an integrated Placido disc topographer. METHODS: The VisuMax 500-kHz femtosecond laser (Carl Zeiss Meditec AG) and Amaris 750 excimer laser (SCHWIND eye-tech-solutions) were used. Central, paracentral, and 6-mm epithelial thickness values were obtained, and the change in the value of epithelial thickness was calculated. Changes in the refractive power of the epithelium were also evaluated. The repeatability of this new measurement was also analyzed using the intraclass correlation (ICC). The total follow-up period was 6 months. RESULTS: A total of 77 LASIK eyes were matched with 77 SMILE eyes. Mean spherical equivalent was -3.92 ± 1.67 diopters (D) for LASIK versus -4.02 ± 1.63 D for SMILE (P = .356). Epithelial thickness parameters significantly and equally thickened in both types of surgery. The change in the value of epithelial thickness was positively correlated with spherical aberration. Analysis of the refractive power of the corneal epithelial layer (ICC > 0.70) showed a tendency for the postoperative myopization of the refractive component of this layer (-0.11 D for SMILE and -0.53 D for LASIK at 3 mm) and an increase in its cylinder and aberrometry. Increasing postoperative spherical aberration and epithelial thickness increased myopization of the epithelial refractive sphere (P < .05). CONCLUSIONS: Corneal epithelium thickens similarly after LASIK and SMILE, being slightly higher after SMILE. This correlates with the induced spherical aberration. Corneal epithelium thickening induces myopization of its refractive power, which accounts for a slight regression of the net refractive power change on the treated cornea. [J Refract Surg. 2022;38(9):602-608.].