RESUMEN
BACKGROUND: High myopia represents a health issue and leads to the development of complications that threaten vision. The study of macular changes in high myopia patients has undergone great advances with updated technology via new spectral optical coherence tomography (OCT) and Optical coherence tomography angiography (OCTA). Most of related studies have focused on the adults and additional studies need to investigate macular changes in children and adolescents. This study aimed to evaluate the changes in the macular structure by OCT and the macular vessel density in high myopia in children and adolescents by OCTA. METHODS: A cross-sectional comparative study. The population was divided into two groups: group 1 (4-11 years) and group 2 (12-18 years). The results were comparable to those of control study of the same age group. The two high myopia groups and the control groups were examined by macular OCT and OCTA to evaluate macular thickness and vessel density in the superficial and deep capillary plexuses. RESULTS: OCT measurements of patients in group 1 revealed that central macular thickness was significantly lower in high myopia group than in the control group and measured 220.91 ± 27.87 µm and 258.23 ± 17.26 µm, respectively, (P < 0.0001). However, in group 2 the central macular thickness in the high myopia group and control group was 236.32 ± 27.76 µm and 247.09 ± 16.81 µm respectively, and the difference was not statistically significant (P = 0.09). The parafoveal macular thickness and the perifoveal macular quadrants thickness were significantly lower in high myopic children and high myopic adolescents (P < 0.0001) than age matched controls. The parafoveal and perifoveal vessel densities in the superficial and deep capillary plexuses were lower in the high myopia groups than in the age-matched controls in both groups with a few segment exceptions in group 1. The FAZ was significantly wider in group 1 than in the age-matched emmetropes (P = 0.02). The FAZ was wider in group 2 than controls, but the difference was not statistically significant, (P = 0.75). CONCLUSION: High myopic children and adolescents have thinner macular thickness than comparable age-matched emmetropes and have less vessel density in superficial and deep capillary plexuses with a wider FAZ.
RESUMEN
PURPOSE:: To compare surface alterations between preloaded and manually loaded intraocular lens. METHODS:: Scanning electron microscope was utilized to evaluate surface alteration and deposits in four different types of intraocular lenses: preloaded hydrophobic acrylic, preloaded hydrophilic acrylic, manually loaded hydrophobic acrylic, and manually loaded hydrophilic acrylic. Six lenses with different powers (+6 D, +22 D, and +29 D) were used from each category, to represent different thickness categories of the intraocular lenses. RESULTS:: In total, 30 intraocular lenses have been evaluated in this study: 4 from the control group (2 hydrophobic and 2 hydrophilic lenses) and 12 from the preloaded intraocular lens and manually loaded groups (6 hydrophilic and 6 hydrophobic lenses with different powers). Surface deposits were found in eight hydrophobic intraocular lenses compared to a single intraocular lens with scattered deposits on the optical surface of a hydrophilic intraocular lens. In manually loaded intraocular lens group, five hydrophobic and one hydrophilic intraocular lenses showed identifiable marks on the optical surface. In the preloaded intraocular lens group, three hydrophobic intraocular lenses showed identifiable marks on the optical surface and three hydrophobic intraocular lenses showed surface wrinkling. All hydrophilic intraocular lenses revealed no identifiable marks. CONCLUSION:: Surface alterations and deposits are a common finding in both preloaded and manually loaded intraocular lenses. Water content of acrylic intraocular lenses is an important factor predisposing to these changes, and hydrophobic intraocular lenses are more vulnerable than hydrophilic lenses. The impact on the final visual outcome needs further studies.
