Taiwan Journal of Ophthalmology最新文献

Purpose: Conjunctival microvasculature is associated with ocular and systemic diseases. Previous studies have reported increased blood flow velocity (BFV), blood flow rate (BFR), vessel density, and diameter in dry eye disease (DED). This study aimed to compare bulbar conjunctival microvascular morphology and hemodynamics between patients with DED with and without Sjögren's dry eye (SSDE and NSDE) who had comparable symptoms, and to assess their correlations with Meibomian gland dysfunction (MGD) parameters.

Materials and methods: In this prospective study, conjunctival imaging for the left eyes of patients with DED was performed using a previously developed optical system incorporating Attention-UNet-based vessel segmentation and a validated two-step motion-correction pipeline. Tear film lipid layer thickness measurement and meibography were performed using the LipiView® II Ocular Surface Inferometer. Microvascular parameters, including BFV, BFR, and diameter, were quantified.

Results: The mean microvessel diameter for the SSDE group (12.985 ± 2.478 μm) was significantly higher than that for NSDE (9.431 ± 3.982 μm) (P < 0.050). In the NSDE group, diameter correlated positively with BFR (P < 0.050), and BFR correlated with both upper and lower meiboscores (P < 0.050).

Conclusion: These findings reveal distinct conjunctival microvascular signatures in patients with SSDE, and support vessel diameter as a discriminator. The association between hemodynamic changes and MGD parameters in the NSDE group underscores the interplay between MGD and conjunctival microcirculation in NSDE. The differences in microvasculature identified in this study may serve as valuable biomarkers for DED subtype classification and the development of personalized treatment.

We prefer using posterior capsular rent is a significant intraoperative complication of cataract surgery, often leading to vision-threatening sequelae if not promptly recognized and appropriately managed. PCR can result from various factors, weak zonules, posterior polar cataracts, including improper phacoemulsification techniques, and excessive instrument manipulation. Early recognition is critical, and swept-source optical coherence tomography and intraoperative assessments can enhance early detection. Prevention strategies focus on meticulous surgical planning, careful hydrodissection, judicious use of phaco power, and maintaining anterior chamber (AC) stability. Techniques such as slow-motion phacoemulsification, femtosecond laser-assisted cataract surgery (FLACS), and capsule-stabilizing devices can reduce the risk of PCR in high-risk cases. Once a rupture occurs, prompt and careful management is essential to prevent further complications such as vitreous loss, retained lens fragments, or intraocular lens (IOL) malposition. Anterior vitrectomy using bimanual or coaxial techniques is crucial for clearing vitreous from the AC and preventing traction on the retina. The choice of IOL implantation depends on the extent of PCR, with options including sulcus-fixated, iris-fixated, scleral-fixated, or ACIOLs when capsular support is inadequate. Postoperative management includes monitoring for cystoid macular edema, retinal detachment, and endophthalmitis, which are more common following PCR. This review underscores the importance of surgical vigilance, adherence to best practices, and an individualized approach to optimizing the visual outcomes following this challenging complication.

Purpose: The purpose of the study was to evaluate macular microvascular alterations using optical coherence tomography angiography (OCTA) in typical retinitis pigmentosa (RP) patients with and without isolated macular lesions, and to assess their relationship with best-corrected visual acuity (BCVA).

Materials and methods: This retrospective study included 77 patients with typical RP from the Taiwan Inherited Retinal Degeneration Project, categorized into two groups: with isolated macular lesions (T+M, n = 44) and without (T, n = 33). Eighteen age-matched healthy individuals served as controls. All participants underwent comprehensive ophthalmic examinations and OCTA imaging. Quantitative parameters-vessel density in superficial and deep retinal plexuses, foveal avascular zone (FAZ) area, and outer retinal flow-were analyzed and correlated with BCVA.

Results: Both RP groups showed compromised macular microcirculation compared to controls. FAZ area was significantly larger in the T+M group than in controls (P = 0.01) and showed a trend toward enlargement compared to the T group (P = 0.06). BCVA was significantly worse in the T+M group than in the T group and controls (P = 0.002). In the T+M group, decreased vessel density in the deep plexus, enlarged FAZ, and reduced outer retinal flow were significantly correlated with poorer vision; these correlations were not observed in the T group.

Conclusion: Macular microvascular impairment is a common feature in typical RP, but its association with central visual loss is particularly pronounced in those with isolated macular lesions. OCTA parameters may serve as useful biomarkers for clinical monitoring and prognosis in this subgroup.

The objective of this review was to provide a summary of the literature on the etiologies and management of positive (PD) and negative dysphotopsia (ND) which are optical phenomena that occur after routine cataract surgery. A search of PubMed and Google Scholar identified 36 relevant papers. There is a consensus on the etiology of PD, which is attributed to the edge design of the intraocular lens (IOL). A truncated square edge can cause light of an oblique incidence to reflect onto the retinal surface and cause streaks and haloes in the visual field. Other causes of PD include diffractive multifocal IOLs and IOLs with a high index of refraction. The causes of ND are multifactorial; however, the majority of the evidence from experimental and clinical studies supports the "illumination gap" of the nasal retina which may arise from the anterior capsule overlying the IOL. Other factors such as pupil size, a high-angle kappa, and increased posterior chamber depth may also play a role. Regarding surgical management, ND has been successfully treated with reverse optic capture, neodymium-doped yttrium aluminum garnet laser capsulectomy, nasal IOL optic truncation, piggyback IOL, and an ND ring. Both PD and ND can be surgically managed by replacing the IOL using in-the-bag exchange or bag-to-sulcus exchange. Technological advancements have presented new avenues for developing antidysphotopsia lenses. Novel approaches utilize anterior capsulotomy fixation using IOL phalanges and a recent diffractive spiral lens that provides smooth full-range vision without dysphotopsia.

Optical coherence tomography (OCT) angiography (OCTA) is a new clinical technology that advances the capabilities of OCT imaging by adding the ability to readily visualize vascular anatomy down to the capillary scale. With this level of detail, OCTA can be used to identify many important vascular pathologies such as capillary dropout, microaneurysms, or neovascularization. Because it offers high-resolution, high-contrast imaging of these and similar features, OCTA is useful not just for visualization but also for quantification. Quantification is a powerful feature that enables the potential for diagnostics, staging, evaluation of treatment response, and patient monitoring in a more rigorous way than simple observation. In this review, we will examine several OCTA measurements with either demonstrated clinical utility or clinical potential through the lens of three prevalent blinding diseases: diabetic retinopathy, age-related macular degeneration, and glaucoma. We will discuss the merits of these various measurements and care that should be taken in their interpretation and analyze their role in patient management.

Intraoperative optical coherence tomography (iOCT) offers valuable real-time, depth-resolved visualization of ocular anatomy and during ophthalmic surgical maneuvers, which can be used to augment clinical decision-making, help verify surgical endpoints, enhance surgical precision, and facilitate the development of novel surgical techniques. Early iOCT demonstrations used perioperative devices, such as handheld and intraocular probes, which required pauses in surgery and disrupted clinical workflow. The advent of microscope-integrated systems addressed these limitations, allowing for iOCT imaging concurrent with surgical microscopy. iOCT image visualization has similarly progressed from external monitors, which require surgeons to divert their gaze, to heads-up displays integrated into microscope oculars, enabling direct overlays and improved ergonomics. Most recent advances have included increasing imaging speed to enable four-dimensional visualization of surgical dynamics and integration of automated surgical instrument tracking technologies. Clinical translation of iOCT has demonstrated utility across a range of procedures, including glaucoma surgery, corneal transplants, cataract extraction, vitrectomy, membrane peel, retinal detachment and macular hole repair, subretinal injection, and retinal prosthesis placement. As more advanced technologies are integrated into the conventional ophthalmic surgical workflow, iOCT has the potential to improve surgical performance and patient outcomes.

Purpose: Hereditary macular dystrophy (MD) usually severely affects the central vision. This study aimed to explore macular microcirculation and its relationship with disease progression in different morphological patterns of MD.

Materials and methods: Sixty-five patients with MD and 26 healthy participants were included. Panel-based next-generation sequencing (NGS), fundus autofluorescence (FAF), and optical coherence tomography angiography (OCTA) were used for genetic diagnosis, morphological classification, and evaluation of macular microcirculation, respectively. Patients were divided into two groups: the central lesion group (CLG) and the dispersed lesion group (DLG), based on FAF findings. The alterations in microcirculation between the groups and subgroups were analyzed and correlated with visual preservation.

Results: A high diagnostic rate of disease-causing genes was achieved with a panel-based NGS test (72.3%). Compromised macular microcirculation was seen in MD of all genotypes. Enlargement of the foveal avascular zone and decreased foveal vessel density was significantly correlated with impaired vision (both P < 0.05). In Stargardt disease, the CLG had an earlier onset than the DLG, with more severely impaired central vision and compromised microcirculation.

Conclusion: OCTA is a reliable, noninvasive tool for evaluating the microcirculation of MD. Our results demonstrate that compromised macular microcirculation occurs with MD, and foveal microcirculation is crucial for visual preservation.

Optical coherence tomography (OCT) is an integral component of present-day ophthalmologic practice. As use of OCT has increased in popularity and frequency of use, a growing number of systemic diseases are now known to have associated findings on both OCT and OCT angiography (OCTA). This review was written to discuss how a multitude of cardiovascular, neurodegenerative, neoplastic, infectious, and autoimmune diseases manifest on OCT and OCTA. The findings thus far highlight the potential utility of OCT and OCTA for diagnosing and monitoring progression of these disease processes. Many current studies are limited by small sample sizes, varying image processing algorithms, image artifact, and differing machines used to acquire images, underscoring the need for further research with increased patient numbers and standardized image acquisition and image processing protocols. Despite these current limitations, the steadily increasing volume of data suggests that there will ultimately be a role for both OCT and OCTA to noninvasively monitor the progression of systemic disease over time.

Purpose: To evaluate quantitative optical coherence tomography (OCT) angiography (OCTA) biomarkers from the choriocapillaris (CC) for detecting early microvascular changes associated with diabetic retinopathy (DR).

Materials and methods: In this retrospective study, 191 macular OCTA images were analyzed from 78 healthy eyes, 64 eyes from diabetic individuals without clinical signs of DR (NoDR), and 49 eyes with mild nonproliferative DR (NPDR). Five CC biomarkers were extracted from 6 mm × 6 mm enface OCTA images: flow deficit density (FDD), FD number (FDN), mean FD size (MFDS), perfusion intensity density (PID), and normalized blood flow index (NBFI). Flow maps were binarized using Phansalkar local thresholding, and statistical comparisons were performed using one-way analysis of variance and two-sample t-tests.

Results: All five biomarkers demonstrated significant differences across study groups (P < 0.001). FDD and MFDS were significantly elevated in both NoDR and mild NPDR eyes compared to controls, indicating increased nonperfusion and enlargement of flow voids. FDN decreased with disease severity, indicating spatial consolidation of capillary loss. PID and NBFI, which reflect flow signal intensity, also declined in diabetic eyes, suggesting a reduction in overall CC perfusion consistent with early vascular compromise.

Conclusion: Quantitative OCTA biomarkers of the CC reveal early microvascular changes in diabetic eyes. Among them, FDN and MFDS demonstrated the highest sensitivity to early disease progression. These findings support the use of CC-derived OCTA features as potential imaging biomarkers for detecting and monitoring early diabetic microvascular dysfunction.