Optical Coherence Tomography Research Articles

Robotics and optical coherence tomography: current works and future perspectives [Invited

Optical coherence tomography (OCT) is an interferometric technique for micron-level imaging in biological and non-biological contexts. As a non-invasive, non-ionizing, and video-rate imaging modality, OCT is widely used in biomedical and clinical applications, especially ophthalmology, where it functions in many roles, including tissue mapping, disease diagnosis, and intrasurgical visualization. In recent years, the rapid growth of medical robotics has led to new applications for OCT, primarily for 3D free-space scanning, volumetric perception, and novel optical designs for specialized medical applications. This review paper surveys these recent developments at the intersection of OCT and robotics and organizes them by degree of integration and application, with a focus on biomedical and clinical topics. We conclude with perspectives on how these recent innovations may lead to further advances in imaging and medical technology.

A Case of Concomitant Acute Zonal Occult Outer Retinopathy and Secondary Nonparaneoplastic Autoimmune Retinopathy

Introduction: Acute Zonal Occult Outer Retinopathy (AZOOR) is a rare inflammatory retinal disease with rapid outer retinal function loss, photopsias, unremarkable fundus findings, and electroretinography (ERG) abnormalities. AZOOR diagnosis can be challenging due to its overlap with other retinal conditions, such as acute idiopathic blind spot enlargement syndrome (AIBES) and autoimmune retinopathies (AIRs). Multimodal imaging, including fundus autofluorescence (FAF) and optical coherence tomography (OCT), has improved detection, revealing progressive outer retinal damage. Although the etiology of AZOOR remains uncertain, autoimmune mechanisms and viral associations have been proposed. Recent studies have identified anti-retinal antibodies, complicating differentiation from other autoimmune retinopathies.. Case Presentation: A 63-year-old male presented with photopsias, floaters, and worsening vision in his left eye. He had a prior diagnosis of autoimmune retinopathy with serum antibodies against enolase, arrestin, and heat shock protein 27 (HSP27). Despite corticosteroid therapy, his visual acuity worsened from 20/20 to 20/60. Fundus examination showed subtle changes, and multimodal imaging revealed outer retinal damage consistent with AZOOR. He was started on mycophenolate mofetil, cyclosporine, and intravenous immunoglobulin (IVIg). Over a year of follow-up, his vision improved to 20/25, and imaging showed stabilization of retinal damage. Conclusion: This case report highlights AZOOR can be associated with secondary npAIR. Multimodal imaging, electrophysiologic testing of retina and RPE, and anti-retinal antibody may be helpful for diagnosis of these patients. A combination of conventional immunomodulatory therapy and IVIg can help with controlling AZOOR and secondary npAIR.

Assessment of interocular symmetry of choroidal vascularity index and thickness in patients with systemic sclerosis: a prospective study

PurposeSystemic sclerosis (SSc) affects blood vessels, internal organs, and skin. In ophthalmology, SSc impacts the choroid. The choroidal vascularity index (CVI) measures the vascular component of the choroid and may serve as a biomarker for the disease staging and prognosis. Studies have reported reduced choroidal thickness and altered CVI in SSc, which supports the theory of vascular damage. This study aimed to examine interocular symmetry in choroidal parameters among SSc patients. It has provided the insight into the disease symmetry and assessed the representativeness of examining one eye.MethodsThis prospective single-center cross-sectional study included 33 patients with SSc and 40 healthy controls. The patients underwent ophthalmological examination (including refraction, visual acuity, IOP, biometry, slit-lamp biomicroscopy, dilated fundus examination, and spectral-domain optical coherence tomography) and rheumatological evaluation. Various parameters of the choroid in the macular and peripapillary regions were analyzed, including choroidal thickness, choroidal volume, and CVI. The interocular asymmetry in the choroidal parameters was quantified using signed and absolute differences. The correlation analysis between the left and right eyes was based on the intraclass correlation coefficient (ICC), Spearman’s correlation coefficient, and paired Wilcoxon test.ResultsThere were no significant differences in the macular and peripapillary choroidal parameters between fellow eyes in both SSc patients and controls (p > 0.05). The parameter that showed the lowest correlation among those examined was CVI—in both groups, as well as in both examined areas. The interocular correlation of choroidal parameters was stronger in the peripapillary area than in the macular area in both groups. In general, the results were confirmed in subgroup analyses stratified according to sex, SSc subtype, Scl70 antibody positivity and previous and/or active digital ulcers.ConclusionThere is interocular symmetry of the choroidal parameters in patients with SSc and controls included in our study. The parameters from one eye are representative of the fellow eye of a given patient. This conclusion may contribute to the design and interpretation of future studies. It also broadens our knowledge of SSc pathophysiology.

Vascular Density and Retinal Structure Relationships Across Sectors and Regions of the Optic Nerve in Patients with Primary Open Angle Glaucoma

Précis: The relationship between structural and hemodynamic parameters in patients with primary open angle glaucoma is strongest in the temporal region of the optic nerve. Purpose: To investigate the relationship between radial peripapillary capillary (RPC) vessel density (VD) and retinal nerve fiber layer (RNFL) thickness in quadrants and sectors of the optic nerve head (ONH) in patients with and without primary open angle glaucoma (POAG). Methods: In a cross-sectional prospective analysis, 191 subjects (80 early-stage POAG; 111 non-glaucomatous controls) were assessed for RNFL thickness and RPC VD in each quadrant [superior (S), inferior (I), nasal (N) and temporal (T)] and sector [inferior-temporal (IT), temporo-inferior (TI), temporo-superior (TS), superior-temporal (ST), inferior-nasal (IN), naso-inferior (NI), naso-superior (NS), and superior-nasal (SN) sectors] of the ONH via optical coherence tomography angiography (OCTA, Avanti, Optovue). Pearson correlations were used to test for associations between measurements, with P<0.05 considered statistically significant. Results: Significantly stronger positive correlations were found between RPC VD and RNFL thickness in the S, I, and T quadrants in POAG patients compared to non-glaucomatous controls (all P<0.05). The temporal quadrant in POAG patients displayed the largest difference in correlation compared to controls. A stronger positive correlation was also found between RPC VD and RNFL thickness in the temporal sectors of the ONH in POAG patients compared to controls, with the largest difference in the TS sector (all P<0.05). Conclusion: Early-stage POAG patients have a stronger relationship between RPC VD and RNFL in the temporal regions of the ONH compared to non-glaucomatous controls, with the TS sector demonstrating the largest difference between groups. Temporal sector VD loss may represent an early-stage biomarker for vascular-linked POAG disease.

Anatomy-driven segmentation of parafoveal optical coherence tomography (OCT) measures may improve associations with clinical outcomes in multiple sclerosis.

Previous investigations on optical coherence tomography (OCT) in multiple sclerosis (MS) focused on generalizable macular and peri-papillary regions without considering the anatomic variations of the retinal layer thickness. This study aimed to assess the utility of parafoveal retinal layer thickness measured by OCT, underscoring its relationships with clinical outcomes in MS. In this cross-sectional study, 214 people with MS (pwMS) and 57 age- and sex-matched healthy controls (HCs) were enrolled. Spectral domain OCT evaluation using 1, 3, 6mm Early Treatment Diabetic Retinopathy Study grid were conducted. The macular and parafoveal thickness (excluding the 1mm foveal/umbo contribution) of the retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), ganglion cell layer (GCL), inner plexiform layer (IPL), and the peri-papillary RNFL (pRNFL) were measured. Multivariable step-wise logistic, linear and generalized estimating equation (GEE) regression models were used to assess the association between the OCT parameters and clinical MS outcomes. The parafoveal RNFL thickness (d = 0.27, p = 0.023), GCL (d = 0.87, p < 0.001), IPL (d = 0.82, p < 0.001), and GCIPL (d = 0.85, p < 0.001) were all significantly lower in pwMS than HCs. Optic neuritis history [odds ratio (OR) = 0.84, p < 0.001] and progressive MS (PMS) status (OR = 0.92, p < 0.001) were bothbest predicted by parafoveal GCL. The Expanded Disability Status Scale (EDSS) was associated with the parafoveal thickness of GCL (standardized β = -0.472, p < 0.001) and pRNFL (standardized β = 0.187, p = 0.021). The parafoveal GCL thickness as predictor of MS disability was also confirmed by the GEE models. This investigation supports the potential use of parafoveal OCT segmentation as an alternative assessment method in detecting neuroinflammatory and neurodegenerative processes in MS. Averaging of the parafoveal retinal layer thickness into the OCT measures may increase the sensitivity of the standard macular OCT segmentation outcomes. Further studies should aim at exploring the reproducibility of this OCT outcome and its longitudinal responsiveness.

Cardiology. Coronary and structural interventional cardiology

The year 2024 has witnessed substantial advancements in interventional cardiology, encompassing both coronary and structural interventions.In coronary field, trials have explored percutaneous innovations for coronary lesions, strategies for managing post‑infarction cardiogenic shock and non‑invasive approaches for guiding revascularization. The uploaded guidelines for chronic coronary syndromes emphasize individualized care, integrating modalities such as fractional flow reserve (FFR), intravascular ultrasound (IVUS), optical coherence tomography (OCT) and new teatments, including cochicine, GLP-1 receptor agonists and bempedoic acid. In structural field, recent trials have confirmed the growing efficacy and safety of percutaneous interventions for aortic, mitral and tricuspid valve diseases, while highlighting theimportance of careful patient selection.

Correlation between mri findings and cebrebrospinal pressures in patients with idiopathic intracranial hypertension

Background: Idiopathic Intracranial Hypertension (IIH) is characterized by elevated intracranial pressure (ICP) without identifiable etiology. While Magnetic Resonance Imaging (MRI) often reveals findings such as empty sella turcica, optic nerve abnormalities, and transverse sinus stenosis, their correlation with cerebrospinal fluid (CSF) pressure remains unclear. Objective: To investigate the correlation between MRI abnormalities and lumbar opening and closing pressures in patients with IIH. Methods: A cross-sectional study was conducted with 21 IIH patients diagnosed using the Modified Dandy Criteria over five years. MRI findings were categorized as normal or abnormal (empty sella, optic nerve abnormalities, and transverse sinus stenosis), and their association with lumbar opening and closing pressures, measured during the initial lumbar puncture, was analyzed using Student's T-test. Results: No statistically significant differences in lumbar opening or closing pressures were observed between patients with normal and abnormal MRI findings (P = 0.605 and P = 0.778, respectively). Similarly, no significant associations were identified for optic nerve abnormalities (P = 0.494 and P = 0.522), venous sinus abnormalities (P = 0.356 and P = 0.370), or empty sella turcica (P = 0.685 and P = 0.591). Conclusion: The study found no significant correlation between MRI findings and CSF pressures in IIH patients. These results align with existing literature, suggesting that MRI findings alone may not adequately predict CSF pressure levels. Alternative diagnostic methods, such as optical coherence tomography, may be more sensitive in detecting early optic nerve abnormalities.

Unraveling the inflammation–degeneration tangle in early MS: preliminary insights from ferritin, neurogranin, TREM2, and retinal ganglion cell layer

BackgroundMultiple sclerosis (MS) involves a complex interplay between immune-mediated inflammation and neurodegeneration. Recent advances in biomarker research have provided new insights into the molecular underpinnings of MS, including ferritin, neurogranin, Triggering Receptor Expressed on Myeloid cells 2 (TREM2), and neurofilaments light chain.ObjectivesThis pilot study aims to investigate the levels of these biomarkers in the cerebrospinal fluid (CSF) of MS patients and explore their associations with clinical, cognitive, and optical coherence tomography (OCT) parameters.MethodsThis cross-sectional pilot study included 26 patients with relapsing MS (RMS) and 13 symptomatic controls (SCs). Clinical, cognitive, and OCT assessments were performed, and CSF samples were analyzed for ferritin, neurogranin, TREM2, and neurofilaments.ResultsNeurogranin levels were significantly higher in RMS patients compared to SCs (p = 0.04), and the receiver-operating characteristic (ROC) analysis indicated that neurogranin could be considered a disease biomarker (AUC = 0.733, p = 0.01). Ferritin and neurogranin showed a strong positive correlation (r = 0.690, p < 0.01), and both were inversely correlated with retinal ganglion cell layer (GCL) thickness. TREM2 was positively associated with baseline Expanded Disability Status Scale score.ConclusionThis pilot study suggests that neurogranin may be a potential biomarker at the time of MS diagnosis, and the interplay between ferritin, neurogranin, and TREM2 highlights the complex relationship between inflammation, oxidative stress, and neuronal damage in MS. The inverse association of ferritin and neurogranin with GCL thickness warrants further investigation into the role of iron metabolism and synaptic damage in the early stages of the disease.

In vivo assessment of regional scleral stiffness by shear wave elastography and its association with choroid and retinal nerve fiber layer characteristics in high myopia.

To evaluate the posterior scleral stiffness of different regions in high myopic eyes and to explore its associations with macular choroidal and peripapillary retinal nerve fiber layer (pRNFL) thickness and vasculature. Thirty subjects with high myopic eyes and 30 subjects with low myopic eyes were included in this study. The elastic modulus of the macular and peripapillary sclera at the temporal, nasal, superior and inferior regions were determined via shear wave elastography (SWE). Optical coherence tomography and angiography (OCT/OCTA) centered on the fovea and optic disc was obtained by using a commercially available swept-source OCT/OCTA device. Built-in automated software was used to quantify macular subfovea choroidal vessel volume (SFCVV), macular subfovea choroidal thickness (SFCT) and pRNFL thickness. The SWE results demonstrated that high myopic eyes had significantly lower macular and peripapillary scleral elastic modulus than low myopic eyes (P < 0.001). The reduction in the elastic modulus was slightly greater in the temporal peripapillary region, followed by the superior peripapillary, inferior and nasal peripapillary regions (P > 0.05). The linear regression analysis demonstrated a significant association between the posterior scleral elastic modulus and SFCT and inferior pRNFL thickness (P < 0.001). High myopic eyes had weakened posterior scleral stiffness. The regional change in the elastic modulus was associated with the SFCT and inferior quadrant pRNFL thickness. This novel in vivo quantitative assessment of scleral stiffness via SWE may help to characterize the underlying pathologic mechanism of scleral biomechanics on choroid and pRNFL changes in high myopia. WHAT IS KNOWN : Previous studies reported significant choroid thickness and peripapillary nerve fiber layer thickness decrease in high myopia The scleral stiffness is weakened in myopic eyes WHAT IS NEW : Shear wave elastography (SWE) is a novel tool to detect posterior scleral biomechanics in myopic eyes in vivo Stiffness of the posterior sclera at macular and peripapillary regions is lower in high myopic than in low myopic eyes The posterior scleral stiffness is correlated with subfovea choroidal thickness and inferior quadrant peripapillary nerve fiber layer thickness.

Self-starting Cr2+:ZnSe femtosecond laser with 200 nm continuous tuning and 96.5 nm bandwidth at 2.2 µm

High-resolution optical diagnostics in the short wavelength infrared (SWIR II) region have gained significant attention in medical research, showing great potential for tissue spectroscopy and visualization due to the region’s low water absorption and scattering coefficients. However, high-beam-quality sources covering an entire spectral range are limited. This paper presents the development of a femtosecond Cr2+:ZnSe laser with a 2.2 µm center wavelength, a pulse duration of 60 fs, a spectral width of 96.5 nm, and an energy of 4.5 nJ. The resulting source is expected to enable spectroscopy and the optical coherence tomography system for diagnosing collagen-rich tissues.

Genetic Characteristics of 63 Patients with Non-syndromic Retinitis Pigmentosa at a Single Korean Institution

Purpose: To investigate the genetic characteristics of patients with non-syndromic retinitis pigmentosa (RP) analyzed at a single institution.Methods: We conducted a retrospective analysis of 63 patients clinically diagnosed with non-syndromic RP who underwent genetic testing. The clinical features of patients exhibiting the most common mutations, &lt;i&gt;EYS&lt;/i&gt; and &lt;i&gt;USH2A&lt;/i&gt;, were further assessed through routine ophthalmic examinations.Results: Of the 63 patients, 22 (34.9%) exhibited significant mutations. Notably, &lt;i&gt;EYS&lt;/i&gt; and &lt;i&gt;USH2A&lt;/i&gt; mutations were each found in 5 patients (7.9%); &lt;i&gt;RP1&lt;/i&gt; mutations were found in 4 patients (6.3%). The average ages at diagnosis were 38.8 years for &lt;i&gt;EYS&lt;/i&gt; mutations and 41.8 years for &lt;i&gt;USH2A&lt;/i&gt; mutations. The average best-corrected visual acuities were logMAR 0.08 for &lt;i&gt;EYS&lt;/i&gt; mutations and logMAR 0.51 for &lt;i&gt;USH2A&lt;/i&gt; mutations. Both mutation types showed a decrease in the normal macular area in fundus photographs with increasing age. In &lt;i&gt;USH2A&lt;/i&gt; mutations, optical coherence tomography revealed a more pronounced reduction in central macular thickness and central foveal ellipsoid length compared with &lt;i&gt;EYS&lt;/i&gt; mutations. Visual field tests indicated a reduction within the central 10° in 40% of &lt;i&gt;EYS&lt;/i&gt; mutations and 60% of &lt;i&gt;USH2A&lt;/i&gt; mutations. Electroretinography showed non-detectable responses in 2 individuals with &lt;i&gt;EYS&lt;/i&gt; mutations and 4 individuals with &lt;i&gt;USH2A&lt;/i&gt; mutations (40% and 80%, respectively).Conclusions: &lt;i&gt;EYS&lt;/i&gt; and &lt;i&gt;USH2A&lt;/i&gt; mutations represented 45% of the genetically identified cases; affected patients typically were diagnosed in their 40s. &lt;i&gt;EYS&lt;/i&gt; mutations tended to preserve retinal function and central foveal structure better than &lt;i&gt;USH2A&lt;/i&gt; mutations.

Peripapillary and Macular Microvasculature of the Retina in Primary Angle Closure Suspect

Purpose: To compare the macular and peripapillary vascular parameters between the primary angle closure suspect (PACS) eyes and normal control eyes using optical coherence tomography angiography (OCTA).Methods: In this retrospective study, 42 PACS subjects and 38 normal individuals are included. Vessel density (VD) and perfusion density (PD) of the macular area and peripapillary area, and fovea avascular zone parameter were analyzed using OCTA and compared between two groups after adjustment for the axial length.Results: There were no statistically significant differences in sex ratio, age, refractive errors and intraocular pressures between both groups. In the peripapillary area, inferior VD and PD in the outer zone were significantly lower in the PACS eyes, while the retinal nerve fiber layer thicknesses were similar between groups (&lt;i&gt;p&lt;/i&gt; = 0.032, 0.026). In the macular superficial capillary plexus, inferior VD and PD in the inner zone, inferior VD and PD, nasal VD and PD in the outer zone were significantly lower in the PACS eyes, whereas ganglion cell inner plexiform layer thickness were similar between both groups (all &lt;i&gt;p&lt;/i&gt; &lt; 0.005).Conclusions: The VDs and PDs of retinal capillaries in PACS eyes, which have no glaucomatous changes in the retinal nerve fiber layer and optic nerve disc, were significantly lower compared to normal eyes.

Relationship between nocturnal blood pressure dip and β-parapapillary atrophy zone choroidal vessel density in normal-tension glaucoma patients

Purpose To investigate the relationship between nocturnal blood pressure (BP) dip and parapapillary choroidal vessel density (pCVD) in patients with normal-tension glaucoma (NTG) Methods This study analyzed 267 eyes of 267 untreated NTG patients who underwent 24-hour (h) intraocular pressure (IOP) and ambulatory BP monitoring in the habitual position. Patients were classified into 3 groups [non-dippers (nocturnal BP dip &lt; 10%), dippers (nocturnal BP dip between 10% and 20%, and over-dippers (nocturnal BP dip &gt; 20%)], and pCVDs were measured by using optical coherence tomography angiography (OCTA) images. Logistic regression analyses were performed to identify clinical factors associated with “over-dipper” cases. Linear regression analyses were conducted to determine the correlation between various clinical variables and pCVD. Results In clinical characteristics, over-dippers exhibited lower pCVD values compared to non-dippers or dippers (P = 0.004). High diurnal intraocular pressure (IOP) fluctuation (P = 0.031), high diurnal mean arterial pressure (MAP) fluctuation (P = 0.001), and low pCVD (P = 0.002) were identified as predictors of being “over-dipper” in multivariable logistic regression analyses. Moreover, peripapillary retinal vessel density (P = 0.040), presence of choroidal microvasculature dropout (P = 0.039), and nocturnal MAP dip % (P = 0.002) showed significant correlations with pCVD according to multivariable linear regression analyses. Conclusion Over-dippers presented with lower pCVD than non-dippers or dippers as measured by OCTA choroidal images. Low pCVD was a predictor of “over-dipper” cases and associated with a greater percentage of nocturnal MAP dip in NTG patients. 24-h ambulatory BP monitoring may provide further information for detecting low pCVD in NTG patients with nocturnal BP dip.

Photopsias are associated with greater levels of depression and anxiety

ABSTRACT Clinical relevance Vitreous floaters have been associated with depressive and anxiety symptoms. However, there is a scarcity in the literature regarding the possible impact of vitreous flashes on the psychological status of the patients. Background Photopsias and vitreous floaters frequently co-exist. Floaters have been accompanied by exacerbated levels of depression and anxiety. The aim of this study was to examine whether the presence of photopsias in patients suffering from vitreous floaters is accompanied by exacerbated levels of anxiety and depression. Methods One hundred and four patients complaining of floaters were included in the study; 51 experienced also photopsias and 53 did not. A comprehensive ocular examination, including funduscopy and optical coherence tomography scans was performed to every patient, while their clinical and demographic data were also assessed. Every participant completed the PHQ-9, the Zung SDS, and the HADS anxiety and depression questionnaires. Results The clinical and demographic data did not differ significantly between the study groups (p > 0.05).The scores of every questionnaire were significantly higher among the patients with vitreous flashes (p < 0.05 for all). After adjustment for several confounders, the values remained significantly impaired. Conclusion Photopsias negatively affect the psychological and mental well-being of the patients, by the terms of amplified levels of depression and anxiety. These findings underscore the necessity for a more holistic approach to managing patients presenting with vitreous flashes.

High-Resolution OCT Reveals Age-Associated Variation in the Region Posterior to the External Limiting Membrane.

To evaluate visibility of a sub-band posterior to the external limiting membrane (ELM) and assess its age-associated variation. In a retrospective cross-sectional study, normal eyes were imaged using a high-resolution spectral-domain optical coherence tomography (SD-OCT) prototype (2.7-µm axial resolution). Volume fusion of six sequential scans (each 500 × 500 A-scans over 6mm × 6mm) was performed in the motion correction and volume reconstruction in OCT (MoReOCT) framework to enhance feature visibility in OCT. The subjects were divided into three groups: young (21-40 years old), middle (41-60 years old), and older (>60 years old). Three expert graders assessed the visibility of the sub-band on B-scans, and its A-scan intensity relative to ELM intensity (peak intensity ratio) was measured. Forty-four eyes of 44 subjects were imaged. The sub-band, tentatively attributed to the photoreceptor myoid, can be visualized under high-resolution OCT. The B-scan gradings showed that sub-band visibility increased with age (visible in 16.7%, 47.2%, and 66.7% of the young, middle, and older age groups, respectively). The gradings were statistically different among age groups at 1mm and 2mm nasal and 1mm and 2mm temporal (P < 0.04) from the foveal center. Similarly, the mean peak intensity ratios of the sub-band to the ELM were 71.6%, 77.5%, and 85.2% in the young, middle, and older age groups, respectively, and were positively correlated with age at 1mm temporal (P = 0.012) and 2mm temporal (P < 0.001). High-resolution OCT, combined with advanced volume fusion, enables visualization of the photoreceptor myoid and investigation of its age-associated variations. Investigating the sub-band can advance our understanding of photoreceptors and their association with aging and disease pathogenesis.

New Directions for Ophthalmic OCT - Handhelds, Surgery, and Robotics.

The introduction of optical coherence tomography (OCT) in the 1990s revolutionized diagnostic ophthalmic imaging. Initially, OCT's role was primarily in the adult ambulatory ophthalmic clinics. Subsequent advances in handheld form factors, integration into surgical microscopes, and robotic assistance have expanded OCT's utility and impact outside of its initial environment in the adult outpatient ophthalmic clinic. In this review, we cover the use of OCT in the neonatal intensive care unit (NICU) environment with a handheld OCT, recent developments in intraoperative OCT for data visualization and measurements, and recent work and demonstration of robotically aligned OCT systems outside of eye clinics. Of note, advances in these areas are a legacy of our colleague, the late Joseph Izatt. OCT has been an important innovation for ocular diagnostics, and these advances have helped it continue to extend in new directions.

Multimodal imaging findings of the fellow eye in Stellate Nonhereditary Idiopathic Foveomacular Retinoschisis (SNIFR)

Purpose: This study examines the multimodal imaging (MMI) findings in two cases of unilateral Stellate Nonhereditary Idiopathic Foveomacular Retinoschisis (SNIFR), including detailed findings from the unaffected fellow eye. Methods: Macular spectral domain optical coherence tomography (OCT) and 3x3 mm optical coherence tomography angiography (OCTA), microperimetry, full-field electroretinography (ff-ERG) for both the affected and the fellow eye were reviewed. Results: The MMI findings were consistent across the two cases (71-year-old female and 60-year-old female). OCT imaging of the affected eyes revealed cystoid spaces between the outer nuclear layer (ONL) and the outer plexiform layer (OPL), with the vascular network remaining intact, indicating no alterations in vessel flow. Microperimetry showed slightly lower pointwise sensitivity in both eyes compared to a normative database. Conclusion: Although SNIFR typically presents as a unilateral condition, our findings suggest that patients may have an inherent structural predisposition to macular schisis, resulting in subtle functional impairments. We hypothesize that the structural damage may involve the macular Müller cells. These observations highlight the importance of further studies to understand SNIFR’s pathophysiology and inform therapeutic approaches.

Relationship Between Intraocular Pressure and the True Rate of Functional and Structural Progression in the United Kingdom Glaucoma Treatment Study.

To investigate the effect of average intraocular pressure (IOP) on the true rate of glaucoma progression (RoP) in the United Kingdom Glaucoma Treatment Study (UKGTS). UKGTS participants were randomized to placebo or Latanoprost drops and monitored for up to two years with visual field tests (VF, 24-2 SITA standard), IOP measurements, and optic nerve imaging. We included eyes with at least three structural or functional assessments (VF with <15% false-positive errors). Structural tests measured rim area (RA) with Heidelberg retina tomography (HRT) and average peripapillary retinal nerve fiber layer (pRNFL) thickness with optical coherence tomography (OCT). One eye of 436 patients (222 on Latanoprost) was analyzed. A Bayesian hierarchical model estimated the true RoP of VF and structural metrics, and their correlations, using sign-reversed multivariable exponential distribution. RA and pRNFL measurements were converted to a dB scale, matching the VF metric (mean deviation [MD]). The effect of average IOP on the true RoPs was estimated. True RoP at the mean average IOP (17 mm Hg) was faster (P < 0.001) for VF-MD (-0.59 [-0.73, -0.48] dB/year) than HRT-RA (-0.05 [-0.07, -0.03] dB/year) and OCT-pRNFL (-0.08 [-0.11, -0.06] dB/year). The proportional acceleration of RoP per mm Hg increase was, however, not significantly different (smallest P = 0.15). Accounting for the structural floor-effect largely eliminated the differences in RoPs (smallest P = 0.25). VF appeared to deteriorate at a faster rate than structural measurements. However, this could be explained by the floor-effect from nonfunctional tissue. IOP induced a similar acceleration in RoP per mm Hg increase.

A Survey on Optical Coherence Tomography—Technology and Application

This paper reviews the main research on Optical Coherence Tomography (OCT), focusing on the progress and advancements made by researchers over the past three decades in its methods and medical imaging applications. By analyzing existing studies and developments, this review aims to provide a foundation for future research in the field.

In Vivo Confocal Microscopy Findings in Corneal Stromal Dystrophies

Background/Objectives: In this study, we aim to evaluate in vivo confocal microscopy (IVCM) findings of corneal stromal dystrophies (CSDs) including granular, macular and lattice corneal dystrophy that can be used for differential diagnosis and monitoring recurrences after surgical interventions. Methods: Patients diagnosed with CSD who were followed-up in the cornea and ocular surface unit were included in this study. IVCM was performed using the Heidelberg Retina Tomograph 3, Rostock Cornea Module (Heidelberg Engineering, Germany) and anterior segment optical coherence tomography (AS-OCT) imaging was performed using the Spectralis OCT (Heidelberg Engineering, Germany). The morphological structure, size and location of deposits, epithelial involvement and presence of inflammatory and dentritic cells were compared among the three stromal dystrophies. Results: A total of 72 eyes from 36 participants were included in this study. Twelve patients (33.33%) had granular corneal dystrophy (GCD), ten (27.77%) had macular corneal dystrophy (MCD) and fourteen (38.88%) had lattice corneal dystrophy (LCD). In GCD, highly reflective deposits varying in size (20 µm–300 µm) were observed. In MCD, diffuse hyperreflective stroma with dark striae, dentritic cells around deposits and abnormal keratocytes were observed. In LCD, there were branching, lattice-like and granular deposits with epithelial cell disruption in some of the eyes. In MCD, the central corneal thickness was thinner (449.44 ± 65.45 µm) compared to GCD and LCD (565.16 ± 49.62 µm and 569.91 ± 39.32 µm p &lt; 0.001). Recurrence was observed in five patients following penetrating keratoplasty. Conclusions: IVCM is a valuable tool for distinguishing CSD subtypes and monitoring recurrence following surgical interventions.