Current Issue : July-September Volume : 2025 Issue Number : 3 Articles : 5 Articles
Background and Objectives: The cornea protects the eye from external influences and contributes to its refractive power. Corneas belong to the most frequently transplanted tissues, providing a last resort for preserving the patient’s vision. There is a high demand for donor corneas worldwide, but almost 4% of these transplants are not eligible due to microbial contamination. The objective of this study is to ascertain the suitability of 222 nm Far-UVC irradiation for the decontamination of corneas without damaging corneal endothelial cells. Materials and Methods: To assess the destructive effect of irradiation and, thus, identify the applicable dose needed to decontaminate the cornea without interfering with its integrity, 141 porcine corneas were irradiated with 0, 60 or 150 mJ/cm2 at 222 nm. In the second step, a series of 13 human corneas were subjected to half-sided irradiation using 15 or 60 mJ/cm2 at 222 nm. After five days of in vitro culturing, the endothelial cell density of the non-irradiated area of each human cornea was compared to the irradiated area. Results: Irradiation with up to 60 mJ/cm2 had no detectably significant effect on the cell integrity of human corneas (p = 0.764), with only a minimal reduction in cell density of 3.7% observed. These findings were partially corroborated by tests on porcine corneas, wherein the variability between test groups was consistent, even at increased irradiation doses of up to 150 mJ/cm2, and no notable effects on the irradiated porcine endothelium were monitored. The efficacy of the antimicrobial treatment was evident in the disinfection tests conducted on corneas. Conclusions: These initial irradiation experiments demonstrated that 222 nm Far-UVC radiation has the potential to decontaminate the cornea without compromising sensitive endothelial cell viability....
This study compared the refraction measurements of the ClickCheck™ device (CCD), Topcon KR-8000, and subjective clinical refractometry (SCR) in Brazilian public school students with limited access to eye care. Eighty-seven eyes of healthy students aged 7 to 17 underwent refractometry using the CCD, Topcon KR-8000, and SCR methods under cycloplegia, with only the right-eye data analyzed. For comparison, the measurements were converted into spherical equivalents (SEs) and vector magnitudes. The mean SE difference between CCD and Topcon KR-8000 was−0.27 ± 0.58 (p < 0.0001), while the vector magnitudes at the 90◦ and 135◦ meridians were −0.23 ± 0.55 (p = 0.0001) and +0.04 ± 0.47 (p = 0.2246), respectively, demonstrating no clinical relevance. Similarly, the mean SE difference between CCD and SCR was −0.18 ± 0.58 (p = 0.065), with vector magnitudes of −0.20 ± 0.50 (p = 0.0003) at 90◦ and +0.03 ± 0.46 (p = 0.3730) at 135◦, also lacking clinical relevance. Despite statistically significant differences between the methods, the findings confirm strong agreement, validating CCD as an effective refractive assessment tool for children in low-resource settings. These methods can enhance access to refraction services in underserved populations....
Background and Objectives: Age-related macular degeneration (AMD) remains a leading cause of legal blindness. Anti-Vascular Endothelial Growth Factor (VEGF) agents are the first-line treatment for neovascular AMD (nAMD). The choroid plays a key role in AMD and is affected by the anti-VEGF treatment. Faricimab, a bispecific antibody additionally targeting angiopoietin 2 (Ang2), was recently approved for nAMD treatment. This study investigates the effect of Faricimab on choroidal flow signal. Materials and Methods: Optical coherence tomography angiography images of 29 nAMD eyes were examined retrospectively. Patients had received treatment with other anti-VEGF agents before Faricimab application. The flow signal in the choroid was measured before, after one and after a series of ≥2 Faricimab injections. Results: The flow signal decreased significantly (p = 0.026) at the choriocapillaris (CC) level after ≥2 injections. The flow signal did not show a significant change in Haller’s layer but increased slightly in Sattler’s layer (p = 0.034). Conclusions: In conclusion, our results show that the flow signal, especially at the CC level, changed during treatment. Despite the known influence of anti-VEGF treatment on the choroid, auxiliary inhibition of Ang2 might enhance this effect. Due to the retrospective nature, moderate sample size and non-treatment, naïve patients, care must be taken while interpreting our observations. Prospective studies with larger sample sizes and treatment-naïve patients will be needed....
Aim: The aim of this paper is to assess the changes in optical coherence tomography angiography (OCTA) parameters among normal individuals and for type 2 diabetes mellitus (DM) patients, with and without retinopathy, in the adult Saudi population. Methods: This was a prospective cross-sectional study; subjects were divided into four groups. Group 1, the control group, consisted of 40 eyes from normal healthy individuals, while the other three groups included subjects diagnosed with type 2 DM at various stages of retinopathy. All subjects’ OCT and OCTA images were acquired using a swept-source OCT (DRI Triton, Topcon, Inc., Tokyo, Japan). Parameters collected included superficial capillary plexus (SCP) vessel density (VD), foveal avascular zone (FAZ), macular thickness (MT), ganglion cell layer (GCL) thickness, and retinal nerve fiber layer (RNFL) thickness at central and perifoveal locations. OCTA acquisition included a 4.5 × 4.5 mm scan to measure FAZ and SCP VD, with the FAZ manually mapped onto OCTA images at the SCP. Results: There was a significant decrease in SCP VD (p < 0.05) in all quadrants except the central as the severity of diabetes increased. SCP VD was considerably lower in DM patients without retinopathy compared to controls. Additionally, the FAZ area exhibited a significant increasing trend as the severity of diabetic retinopathy (DR) increased. Regression analysis showed a significant decrease in RNFL thickness (p < 0.01) and GCL thickness (p < 0.01) in the nasal quadrant as DR severity increased, even after adjusting for age, gender, and mean arterial pressure. Furthermore, SCP VD showed a significant negative correlation with both the duration of DM and contrast sensitivity. Conclusions: OCT and OCTA parameters were significantly different between the control and diabetic patients with and without DR. The observed microvascular and contrast sensitivity alterations may precede detectable DR damage or changes in visual acuity....
Background: To investigate the retinochoroidal and optic nerve head (ONH) microstructural and microvascular age-related changes in healthy subjects by examining the ganglion cell–inner plexiform layer thickness (GC-IPLT), vessel density (VD), and their ratio. Methods: In this cross-sectional study, 203 subjects (20–69 years old) were divided into five age groups: 20–29 (G1), 30–39 (G2), 40–49 (G3), 50–59 (G4), and 60–69 (G5) (G5). Following a thorough ophthalmological examination, enhanced depth imaging optical coherence tomography (EDI-OCT) scanning was performed along with OCT angiography (OCTA) in a 6 × 6 mm2 scanning area. Results: After adjusting for axial length the GC-IPLT varied significantly among groups, with thickness peaking in G3 (39.63 ± 1.14 μm) and then decreasing to the lowest in G5 (34.15 ± 5.93 μm) (p = 0.008). The whole, foveal, parafoveal, and perifoveal superficial and deep capillary plexus (SCP and DCP) VDs all varied significantly among groups, peaking in G2 and falling to their lowest in G5 (p < 0.05). No significant differences existed among groups regarding the GC-IPLT/whole SCP VD (p = 0.163) or GC-IPLT/whole DCP VD (p = 0.258) ratios. The foveal VDs in a 300-μm wide region surrounding the foveal avascular zone (FAZ) (FD-300) varied significantly among groups, peaking in G1 (57.06 ± 0.58) and dropping to its lowest in G5 (53.54 ± 0.59) (p < 0.05). The choriocapillaris flow differed significantly among groups, peaking in G1 (20.39 ± 0.15 mm2) and dropping to its lowest in G5 (19.24 ± 0.16 mm2) (p < 0.001). Conclusions: The retinochoroidal microstructure and microvasculature ratios display an inverted U-shaped pattern with age, which could be linked to a considerably decreased GC-IPLT versus capillary plexus VDs with age, notably in subjects in their sixties....
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