Purpose: This study aimed to investigate the relationship between the graft–host junction (GHJ) configuration and postoperative astigmatism in patients who underwent penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK) and to examine whether variations in epithelial thickness are associated with astigmatic outcomes. Methods: A retrospective analysis was conducted on 54 phakic eyes (30 PK and 24 DALK) with a minimum follow-up of 12 months. GHJ morphology was evaluated using anterior segment optical coherence tomography (AS-OCT). Epithelial thickness was measured in the steepest and flattest corneal areas using RTVue XR. Astigmatism was quantified by auto-refraction, keratometry, and corneal topography. Based on GHJ configuration, eyes were classified as either well-aligned or malaligned. Results: Malalignment of the GHJ was observed in 87.1% of cases. Eyes with malaligned junctions exhibited significantly higher astigmatism across all measurement techniques (P < 0.05). The correlation between GHJ configuration and astigmatism was strong in the DALK group but did not reach statistical significance in the PK group. Malalignment was more frequent following PK than DALK (P = 0.002). The epithelial thickness was significantly lower in the flattest zone (P = 0.006), while the increase in the steepest zone was not significant (P = 0.4). Conclusion: Optimal graft–host junction alignment remains a key determinant of refractive success following corneal transplantation. Integrating intraoperative OCT, femtosecond-assisted trephination, and individualized suturing strategies may help reduce postoperative malapposition and astigmatism. Future prospective studies incorporating epithelial remodeling and visual quality analysis will further clarify the mechanisms linking structural alignment and optical performance after keratoplasty.
H. Hashemian, Zahra Kianzad, Seyed Mohammad Naser Hashemian et al.· Indian Journal of Ophthalmol...· 0 citations
We developed a cost-effective, software-based densification pipeline to overcome the diagnostic limitations of standard 2D OCTA projections, enabling the comprehensive assessment of 3D retinal vascular structures without the need for expensive and inaccessible hardware-based 3D upgrades. We developed a software-based pipeline for 3D densification and reconstruction of retinal vasculature from sparse OCTA B-scan volumes, involving Hue, Saturation, Value (HSV)-based thresholding for layer and vessel segmentation, 5th-order spline interpolation along the y-axis, standard deviation projection for en face views, and affine registration. The method was applied to 304 B-scans per volume from 16 eyes (9 healthy controls, mean age 32 ± 5 years; 7 with diabetic retinopathy, mean age 48 ± 7 years, mild-to-severe NPDR) acquired using a 70 kHz SD-OCT system (RTVue-XR, Optovue, CA). Densification and reconstruction accuracy was evaluated against device-generated 2D en face projections using Dice scores and vessel density metrics, with layer-specific analysis for superficial, deep, and full retina. Post-interpolation, the method achieved mean Dice scores of 0.8321 ± 0.0148 (full retina), 0.7993 ± 0.0309 (superficial), and 0.6871 ± 0.0624 (deep), markedly improving from pre-interpolation values (e.g., full retina: 0.4028 ± 0.0161; p < 0.01). 3D vessel density more than doubled post-interpolation (e.g., full retina: from 0.0778 ± 0.0125 to 0.2095 ± 0.0331), resolving capillary discontinuities. Pathologic eyes showed a trend toward reduced 3D vessel density, particularly in the deep layer (healthy: 0.1803 ± 0.0446 vs. pathologic: 0.1584 ± 0.0330; p = 0.0703), consistent with microvascular dropout in diabetic retinopathy. However, these differences did not reach statistical significance (p > 0.05), likely due to the modest sample size. This hardware-independent software method enables detailed layer-specific 3D visualization of retinal vasculature from sparse OCTA B-scan volumes. By providing enhanced spatial context, it has the potential to support the clinical evaluation of vascular abnormalities. An interactive tool further allows real-time exploration, serving as a cost-effective bridge for 3D volumetric analysis in resource-limited clinics. However, because this approach currently relies on a manual data extraction workaround rather than fully automated workflow integration, and because its direct impact on diagnostic accuracy remains unproven, larger cohort validation and formal clinical diagnostic studies are warranted.
Pooya Janani, Seyed Ali Abdollahian, Mobina Amanollahi et al.· Discover medicine· 0 citations
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