Comparative accuracy of intraocular lens power calculation formulas when targeting myopia.

Purpose: This study aims to compare the accuracies of intraocular lens (IOL) power calculation formulas when targeting myopia versus emmetropia. Methods: A total of 450 patients were included, with 225 patients targeting emmetropia and 225 patients aiming for approximately -2.0 diopters of myopia. This retrospective analysis utilized data from a single eye of each patient, with preoperative biometric measurements obtained using the IOL Master 700. The study considered established formulas such as Haigis, Hoffer Q, Holladay 1, Holladay 2, and SRK/T, as well as modern formulas including Barrett Universal II, Cooke K6, EVO 2.0, Hill-RBF, Hoffer QST, Kane, Olsen, and PEARL-DGS. Statistical analyses, including Friedman test and post hoc analysis, were employed to compare the accuracy of each IOL power calculation formula between the two groups. Additionally, a multiple regression analysis was conducted to identify variables influencing the accuracy of intraocular lens power calculation formulas. Results: In targeting myopia, all IOL formulas tended to exhibit a greater refractive error compared to when targeting emmetropic eyes. Notably, the Haigis, SRK/T, and Holladay 2 formulas were found to be highly influenced by this trend, while the modern formulas were less affected. Conclusion: The accuracy of IOL power calculation formulas diminishes when targeting myopia in comparison to emmetropia. However, the modern formulas appear less susceptible to this trend. Consequently, when aiming for myopia, the use of the modern formulas is recommended for enhanced accuracy in IOL power calculation.

In Vivo Human Lacrimal Gland Imaging Using an Ultrasound Biomicroscopy.

PURPOSE: In the present study, we introduce human lacrimal gland imaging using an ultrasound biomicroscopy (UBM) with a soft cover and show their findings. METHODS: The representative UBM findings of palpebral lobes in seven subjects (four with non-Sjögren dry eye syndrome, one with Sjögren syndrome, and two healthy subjects) were described in this study. To prolapse the palpebral lobe, the examiner pulled the temporal part of the upper eyelid in the superotemporal direction and directed the subject to look in the inferonasal direction. We scanned the palpebral lobes longitudinally and transversely using UBM. We used an Aviso UBM with a 50 MHz linear probe and ClearScan. RESULTS: In UBM of two healthy subjects, the echogenicity of the lacrimal gland was lower than that of the sclera and homogeneous. But the parenchyma of a patient with Sjögren dry eye syndrome was quite inhomogeneous compared to the healthy subjects. In two patients with dry eye syndrome, we were able to observe some lobules in the parenchyma. We could find excretory ducts running parallel at the surface of the longitudinal section in some subjects. In the longitudinal UBM scan of a subject, we observed a tubular structure at a depth of 1,500 µm that was considered a blood vessel. It ran from the superonasal to the inferotemporal direction. In a subject, we observed a large cyst beneath the conjunctiva. CONCLUSIONS: Lacrimal gland imaging using UBM has both advantages of optical coherence tomography and sonography, and could be useful for evaluating dry eye syndrome.

Changes in Neurodegeneration and Visual Prognosis in Branch Retinal Vein Occlusion after Resolution of Macular Edema.

This study aimed to examine the thicknesses of the ganglion cell layer (GCL) and peripapillary retinal nerve fiber layer (RNFL) in eyes with resolved macular edema (ME) in branch retinal vein occlusion (BRVO) and determine their relationship with visual acuity (VA). This retrospective observational case-control study included 57 eyes of BRVO patients with resolved ME after treatment. The macular GCL thickness, peripapillary RNFL thickness, and central macular thickness (CMT) measured on swept-source optical coherence tomography scans with the contralateral eyes used as controls were evaluated. The mean CMT was 270.48 ± 32.7 µm; the mean RNFL thickness was 105.46 ± 25.94 µm in BRVO eyes. Although the average RNFL thickness was decreased in BRVO eyes compared to unaffected eyes, there was no significant difference between the groups. However, the temporal and nasal RNFL thicknesses were significantly different between the groups. The mean affected quadrant had a significantly thinner GCL compared to the corresponding opposite unaffected quadrant (p = 0.02). Final VA was significantly correlated with nasal and middle GCL thicknesses in the affected area (r = -0.512, p = 0.003 and r = -0.537, p = 0.001, respectively); no correlation was found between the average RNFL thickness and mean CMT. The peripapillary RNFL and GCL thicknesses of the affected area were reduced in BRVO eyes compared to unaffected eyes. VA significantly correlated with nasal and middle GCL thicknesses in the affected area. Inner retinal damage occurring in patients with ME secondary to BRVO may be related to the visual prognosis.