Anatomical and Micro-CT measurement analysis of ocular volume and intraocular volume in adult Bama Miniature pigs, New Zealand rabbits, and Sprague-Dawley rats.

AIM: Utilizing a combination of micro-computed tomography (micro-CT) and anatomical techniques for the volumetric assessment of the eyeball and its constituents in Bama Miniature Pigs, New Zealand rabbits, and Sprague-Dawley(SD) rats. METHOD: Six Bama Miniature pigs, New Zealand rabbits, and SD rats were enrolled in the study. Micro-CT and gross volumetric estimation of ocular volume were employed to acquire data on ocular volume, anterior chamber volume, lens volume, and vitreous cavity volume for each eye. RESULTS: The eyeball volume of pigs ranges from approximately 5.36 ± 0.27 to 5.55 ± 0.28 ml, the lens volume from approximately 0.33 ± 0.02 to 0.37 ± 0.06 ml, the anterior chamber volume from approximately 0.19 ± 0.05 to 0.28 ± 0.04 ml, and the vitreous volume is approximately 3.20 ± 0.18 ml. For rabbits, the eye volume, lens volume, anterior chamber volume, and vitreous volume range from approximately 3.02 ± 0.24 to 3.04 ± 0.24 ml, 0.41 ± 0.02 to 0.44 ± 0.02 ml, 0.23 ± 0.04 to 0.26 ± 0.05 ml, and 1.54 ± 0.14 ml, respectively. In SD rats, the volumes are 0.14 ± 0.02 to 0.15 ± 0.01 ml for the eyeball, 0.03 ± 0.00 to 0.03 ± 0.00 ml for the lens, 0.01 ± 0.00 to 0.01 ± 0.01 ml for the anterior chamber, and 0.04 ± 0.01 ml for the vitreous volume. CONCLUSION: The integration of micro-CT and gross volumetric estimation of ocular volume proves effective in determining the eyeball volume in Bama Miniature Pigs, New Zealand rabbits, and SD rats. Understanding the volume distinctions within the eyeballs and their components among these experimental animals can lay the groundwork for ophthalmology-related drug research.

Precise prediction of size of a foldable capsular vitreous body via computerized three-dimensional ocular reconstruction in severe retinal detachment.

BACKGROUND: This study aimed to precisely predict the size and silicone oil injection of a foldable capsular vitreous body (FCVB) via computerized three-dimensional (3D) ocular reconstruction in the treatment of severe retinal detachment in China. METHODS: The 3D software Unigraphics NX was applied to determine the volume of the inner cavity with 16-30 mm axial length, assigning the anterior and posterior chambers, the FCVB sizes, and the silicone oil injection volume, and modeling the data between the axial length and the FCVB size. In clinical practice, IOL Master was applied to accurately measure the axial length of the contralateral healthy eye to anchor the anterior-posterior and horizontal diameters of the operated eye in horizontal position CT, and compared with the model to recommend the FCVB size and silicone oil amount, and the clinical effect was validated in cases across five hospitals in China. RESULTS: For the axial length of 16-30 mm, the volume of the inner cavity is 1.2 ml-8.4 ml. FCVB size and silicone oil volume were recommended based on this volume of the inner cavity. Of 253 cases, we noted 11 cases implanted with AV-10P and 1.05 ± 0.21 ml of silicone oil, 41 with AV-12P and 1.58 ± 0.18 ml of silicone oil, 163 with AV-13.5P and 2.48 ± 0.29 ml of silicone oil, 31 with AV-15P and 3.57 ± 0.39 ml of silicone oil, and 7 with AV-17P and 5.71 ± 0.81 ml of silicone oil. There was no significant difference in postoperative visual acuity scores compared with preoperative (P = 0.097), postoperative IOP(10.29 ± 0.57mmHg)was slightly higher than preoperative IOP (9.76 ± 0.48 mmHg), but there was still no statistically significant difference between the two comparisons (P = 0.405). CONCLUSION: Three-dimensional reconstruction prediction is a good solution for eyeballs with obvious individualized changes in severe retinal detachment, and this method helps doctors standardize FCVB size selection and the silicone oil amount for patients.

ADAPTIVE OPTICS AND MULTIMODAL IMAGING FOR INFLAMMATORY VITREORETINAL INTERFACE ABNORMALITIES.

PURPOSE: To investigate changes to the vitreoretinal interface in uveitis with multimodal imaging including adaptive optics. METHODS: Four eyes (four patients) affected by fovea-attached (subtype 1A) or fovea-sparing epiretinal membranes (ERMs) on spectral-domain optical coherence tomography or visible internal limiting membrane (ILM) on infrared scanning laser ophthalmoscope (SLO) fundus imaging were recruited in this pilot study. The microstructure of the vitreoretinal interface was imaged using flood-illumination adaptive optics (FIAO), and the images were compared with the cross-sectional spectral-domain optical coherence tomography data. RESULTS: Adaptive optics images revealed multiple abnormalities of the vitreoretinal interface, such as deep linear striae in ERM, and hyperreflective microstructures at the location of ERMs and ILMs. The cone mosaic was imaged by FIAO and was found altered in the four eyes with ERMs or visible ILM. The same four eyes presented alteration of photopic 30 Hz flicker that was reduced in amplitude indicating cone inner retinal layer dysfunction. CONCLUSION: FIAO imaging can identify specific patterns associated with ERMs and ILMs. Correlating FIAO imaging of the vitreomacular interface with the structural alterations seen in FIAO at the level of the outer retinal structures can help understand the cause of significant macular dysfunction associated with ERM.

Visualization of distribution in the vitreous cavity via eye drops using ultra-heavily T2-weighted sequences in MRI: a preliminary study with enucleated pig eyes.

We investigated whether magnetic resonance imaging can visualize the distribution in the vitreous cavity via eye drops of ophthalmic solutions, gadolinium-based contrast agent, and 17O-water, and to clarify the usefulness of ultra-heavily T2-weighted sequences in the research of intraocular distribution. Five different solutions (V-ROHTO, TRAVATANZ, gadobutrol, H217O, and saline) were administered to excised pig eye specimens. The samples were scanned using T1 mapping, T2 mapping, 3D T2-weighted (echo times (TE): 500, 3200, and 4500 ms), a half-Fourier single-shot turbo-spin echo sequence (HASTE; TE: 440 and 3000 ms), and 3D-real inversion-recovery before eye drops administration. Subsequently, we used a plastic dropper to drop a 0.5 mL solution each, and images were obtained up to 26 h later. Temporal changes in the T1 and T2 values of the anterior chamber and vitreous cavity were compared. The other sequences were evaluated by determining temporal signal changes as signal intensity ratio (SIR) compared to "No drop." The T1 and T2 values of samples treated with gadobutrol and H217O decreased over time. The SIR of samples treated with gadobutrol and H217O showed remarkable changes in the 3D T2-weighted images, whereas no remarkable temporal changes were observed in the other solutions. Longer TEs resulted in remarkable changes. We demonstrated that visualization of distribution in the vitreous cavity via eye drops could be achieved with excised pig eyes using gadobutrol and H217O, but not with ophthalmic solutions. Ultra-heavily T2-weighted sequences may be promising for the early and highly sensitive visualization of the intraocular distribution of eye drops.

CLINICALLY RELEVANT POSTERIOR VITREOUS DETACHMENT STAGING USING CIRCUMPAPILLARY AND MACULAR VOLUME OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: This study was designed to investigate retinal nerve fiber layer circumpapillary optical coherence tomography to determine posterior vitreous detachment (PVD) status and to develop a clinically relevant PVD grading scale based on retinal nerve fiber layer circumpapillary optical coherence tomography to determine the incidence of PVD by age and association with vitreomacular traction disorders. METHODS: Ophthalmic images and medical records of patients with retinal diseases were retrospectively analyzed by three masked graders using retinal nerve fiber layer circumpapillary optical coherence tomography and macular optical coherence tomography. Based on PVD status, eyes were categorized into five newly defined PVD stages. RESULTS: Among 2002 eyes, PVD stages were as follows: A) 25 (1.25%); B) 725 (36.21%); C-) 248 (12.39%); C+) 151 (7.54%); D) 851 (42.51%); X) 2 (0.1%). Posterior vitreous detachment was correlated with advanced age (P < 0.0001). Limited separation or partial separation between lamella within the posterior vitreous cortex (Stage B) was noted early (68% of eyes <18 years). Overall, 34% of eyes >70 years did not exhibit complete PVD. Of 75 eyes with tractional vitreoretinal disorders, 64 (85.3%) were Stage C-/C+, identifying Stage C as the high-risk "complication" stage. CONCLUSION: Imaging analyses using retinal nerve fiber layer circumpapillary optical coherence tomography and macular optical coherence tomography scans in conjunction allow rapid assessment of the PVD stage. These techniques can assist clinicians and surgeons in counseling patients and planning surgical approaches. Observations confirmed the progression of PVD through predictable stages and the progression of PVD with age.

Optical coherence tomography features in vitreoretinal lymphoma compared with non-infectious uveitis.

BACKGROUND: Vitreoretinal lymphoma (VRL) is a rare intraocular malignancy that poses a diagnostic challenge due to the non-specific clinical presentation that resembles uveitis. The use of spectral domain optical coherence tomography (SD-OCT) has emerged as a valuable imaging tool to characterize VRL. Therefore, we sought to determine the specific OCT features in VRL compared to the uveitides. METHODS: Retrospective chart review of patients who were seen at Mayo Clinic from January 1, 2010 through December 31, 2022. The medical records and SD-OCT images at time of initial presentation were reviewed in patients with biopsy-proven VRL, intermediate uveitis, or biopsy-confirmed sarcoid posterior uveitis. Patients with VRL or similar uveitides including intermediate uveitis or sarcoid posterior uveitis were included. RESULTS: There were 95 eyes of 56 patients in the VRL group and 86 eyes of 45 patients in the uveitis group, of whom 15 (33.3%) were diagnosed with intermediate uveitis and 30 (66.7%) with sarcoid chorioretinitis. The SD-OCT features more commonly seen at initial presentation in VRL patients (vs. uveitis) included preretinal deposits (31.6% vs. 9.3%, p = 0.002), intraretinal infiltrates (34% vs. 3.5%, p < 0.001), inner retinal hyperreflective spots (15.8% vs. 0%, p < 0.001), outer retinal atrophy (22.1% vs. 2.3%, p < 0.001), subretinal focal deposits (21.1% vs. 4.7%, p = 0.001), retinal pigmented epithelium (RPE) changes (49.5% vs. 3.5%, p < 0.001), and sub-RPE deposits (34.7% vs. 0%, p < 0.001). Features more frequently seen in uveitis included epiretinal membrane (ERM) (82.6% vs. 44.2%, p < 0.001), central macular thickening (95.3% vs. 51.6%, p < 0.001), cystoid macular edema (36% vs. 11.7%, p < 0.001), subretinal fluid (16.3% vs 6.4%, p = 0.04), and subfoveal fluid (16.3% vs. 3.2%, p = 0.003). Multivariate regression analysis controlling for age and sex showed absence of ERM (OR 0.14 [0.04,0.41], p < 0.001) and absence of central macular thickening (OR 0.03 [0,0.15], p = 0.02) were associated with VRL as opposed to uveitis. CONCLUSION: OCT features most predictive of VRL (vs. uveitis) included absence of ERM and central macular thickening.

Postmortem changes in the eye on computed tomography images.

BACKGROUND: Ocular tension decreases with increasing postmortem interval (PMI) and eyes collapse with extreme progression of postmortem change; however, time-related changes in postmortem computed tomography (PMCT) findings have not been clarified. This study aimed to quantitatively evaluate the vitreous volume and CT values of the vitreous body to clarify time-related changes in PMCT. METHODS: We retrospectively reviewed PMCT images of the eyes of subjects who underwent autopsy at our institution between July 2023 and February 2024. They were classified into four PMI groups: PMI-1: < 1 day, PMI-2: 1-2 days, PMI-3: 3-6 days, PMI-4: ≥ 7 days. The vitreous volumes and mean CT values of the vitreous chambers were measured. Additionally, the presence of intraocular gas and crystalline lens dislocation was observed. RESULTS: The PMCT images of 131 eyes of 66 patients (41 males, 25 females) were analyzed. The mean age was 63.7 (22-99) years. The volume of the vitreous cavity was significantly decreased at PMI-3 and PMI-4, which indicated scleral depression. Intraocular gas appeared in PMI-4. Lens dislocation began at PMI-3 and was more frequently observed at PMI-4 and in the higher-temperature environment group. CONCLUSION: Ocular findings on PMCT are useful for estimating the time of death.

A journey through the world of vitreous.

Vitreous, one of the largest components of the human eye, mostly contains water. Despite decades of studying the vitreous structure, numerous unanswered questions still remain, fueling ongoing active research. We attempt to provide a comprehensive overview of the current understanding of the development, morphology, biochemical composition, and function of the vitreous. We emphasize the impact of the vitreous structure and composition on the distribution of drugs. Fast-developing imaging technologies, such as modern optical coherence tomography, unlocked multiple new approaches, offering the potential for in vivo study of the vitreous structure. They allowed to analyze in vivo a range of vitreous structures, such as posterior precortical vitreous pockets, Cloquet canal, channels that interconnect them, perivascular vitreous fissures, and cisterns. We provide an overview of such imaging techniques and their principles and of some challenges in visualizing vitreous structures. Finally, we explores the potential of combining the latest technologies and machine learning to enhance our understanding of vitreous structures.

Vitreoretinal Interface Cells Correlate In Vivo With Uveitis Activity and Decrease With Anti-Inflammatory Treatment.

Purpose: To highlight the utility of en face swept-source optical coherence tomography angiography (SS-OCTA) in assessing vitreoretinal interface cells (VRICs) of patients with active uveitis and their dynamics. Methods: In this prospective, single-center study, 20 eyes from patients with active uveitis were analyzed using six 6 × 6-mm macular scans at three time points: active inflammation (baseline), clinically improving (T1), and resolved inflammation (T2). VRICs were visualized using 3-µm en face OCT slabs on the inner limiting membrane. The variation of VRIC number, density, and size over time was assessed, and VRIC measurements were compared with clinical grading. Results: At baseline, the VRIC count was significantly higher (552.5 VRICs) than that of the healthy controls (478.2 VRICs), with a density of 15.3 cells/mm2. VRIC number decreased significantly to 394.8 (P = 0.007) at T1, with a density of 10.9 cells/mm2 (P = 0.007). VRIC size reduced from 6.8 µm to 6.3 µm at T1 (P = 0.009) and remained stable at T2 (P = 0.3). Correlation coefficients between inflammatory parameters (anterior chamber cells and National Eye Institute vitreous haze), and VRIC count indicated a positive correlation at baseline (r = 0.53), weakening at T1 (r = 0.36), and becoming negative at T2 (r = -0.24). Conclusions: En face SS-OCTA revealed increased VRIC number and size in active uveitis, likely due to monocyte recruitment. Post-inflammation control, VRIC number, size, and density significantly decreased, returning to normal despite residual anterior chamber cells or vitreous haze. Translational Relevance: Visualization of VRICs by in vivo OCT opens up new opportunities for therapeutic targets.

[Vitreomacular traction: diagnostics, natural course, treatment decision and guideline recommendations]. / Vitreomakuläre Traktion: Diagnostik, natürlicher Verlauf, Therapieentscheidung und Leitlinienempfehlungen.

Vitreomacular traction is a tractive foveolar adhesion of the posterior vitreous limiting membrane, resulting in pathological structural alterations of the vitreomacular interface. This must be differentiated from physiological vitreomacular adhesion, which exhibits a completely preserved foveolar depression. Symptoms depend on the severity of the macular changes and typically include reduced visual acuity, reading problems and metamorphopsia. High-resolution spectral domain optical coherence tomography (SDOCT) imaging enables classification of the sometimes only subtle morphological changes. If pronounced vitreomacular traction is accompanied by epiretinal gliosis and alterations to the outer retina, it is referred to as a vitreomacular traction syndrome. Vitreomacular traction has a high probability of spontaneous resolution within 12 months. Therefore, treatment should only be carried out in cases of undue suffering of the patient and with symptoms during bilateral vision and a lack of spontaneous resolution. In addition to pars plana vitrectomy, alternative treatment options, such as intravitreal injection of ocriplasmin and pneumatic vitreolysis are discussed for vitreomacular traction with an associated macular hole; however, ocriplasmin is no longer available in Germany. The best anatomical results in comparative investigations were achieved by vitrectomy. Pneumatic vitreolysis is controversially discussed due to the increased risk of retinal tears. In one of the current S1 guidelines of the German ophthalmological societies evidence-based recommendations for the diagnostics and treatment of vitreomacular traction are summarized.

Vitreopapillary Traction in Stickler Type IV COL9A1.

This case report describes a woman aged 43 years with Stickler syndrome and bilateral vitreopapillary traction who presented with shadows and ghosting of vision in both eyes.

The association of symptomatic vitreous floaters with depression and anxiety.

PURPOSE: To evaluate the levels of anxiety and depression in patients with symptomatic vitreous floaters and to determine the possible correlations of psychological implications with the symptoms duration and possible improvement, the degree of posterior vitreous detachment, and the discomfort severity. METHODS: Ninety patients complaining for floaters and fifty-seven age- and gender-matched healthy-control subjects were recruited. Every participant underwent a complete ophthalmological examination, including funduscopy and optical coherence tomography scans, while clinical and demographic data were also gathered. The Patient Health Questionnaire-9 (PHQ-9), the Zung Depression Inventory-Self-Rating Depression Scale (Zung SDS), and the Hospital Anxiety and Depression Scale (HADS) were completed by everyone. RESULTS: Between the studied groups, no significant differences were detected regarding the clinical and demographic data (p > 0.05). The patients with floaters had significantly higher scores of PHQ-9, Zung SDS, HADS Anxiety, and HADS Depression (p < 0.001). After adjustment for several confounders, PHQ-9 (p = 0.041), Zung SDS (p = 0.003), and HADS Anxiety (p = 0.036) values remained significantly impaired. Among the patients, PHQ-9 and Zung SDS scores were significantly elevated in the patients with floaters duration less than 4 weeks (p < 0.05). Finally, anxiety and depression were significantly correlated with the symptoms duration and intensity, with the floater-associated discomfort, and with the stage of posterior vitreous detachment. CONCLUSION: Vitreous floaters have a negative impact on patients' psychological status, by the terms of enhanced depressive and anxiety levels. To the best of our knowledge, our study is the first in the literature to elaborate the aforementioned association, by assessing three different questionnaires simultaneously.

Light Scattering by Vitreous of Humans With Vision Degrading Myodesopsia From Floaters.

Purpose: Vision-degrading myodesopsia (VDM) from vitreous floaters significantly degrades vision and impacts visual quality of life (VQOL), but the relationship to light scattering is poorly understood. This study compared in vitro measures of light scatter and transmission in surgically excised human vitreous to preoperative indexes of vitreous structure, visual function, and VQOL. Methods: Pure vitreous collected during vitrectomy from 8 patients with VDM had wide-angle straylight measurements and dark-field imaging, performed within 36 hours of vitrectomy. Preoperative VQOL assessment with VFQ-25, contrast sensitivity (CS) measurements with Freiburg acuity contrast testing, and quantitative ultrasonography were compared to light scattering and transmission in vitro. Results: All indices of vitreous echodensity in vivo correlated positively with straylight at 0.5° (R = 0.708 to 0.775, P = 0.049 and 0.024, respectively). Straylight mean scatter index correlated with echodensity (R = 0.71, P = 0.04) and VQOL (R = -0.82, P = 0.0075). Dark-field measures in vitro correlated with degraded CS in vivo (R = -0.69, P = 0.04). VQOL correlated with straylight mean scatter index (R = -0.823, P = 0.012). Conclusions: Increased vitreous echodensity in vivo is associated with more straylight scattering in vitro, validating ultrasonography as a clinical surrogate for light scattering. Contrast sensitivity in vivo is more degraded in the presence of dark-field scattering in vitro and VQOL is decreased in patients whose vitreous has increased light scattering. These findings could form the basis for the development of optical corrections for VDM or support new laser treatments, as well as novel pharmacotherapy.

[Isolated primary vitreoretinal lymphoma (case report)]. / Izolirovannaya pervichnaya vitreoretinal'naya limfoma (klinicheskoe nablyudenie).

This case report presents the diagnostic features of isolated primary intraocular lymphoma, which was initially misdiagnosed as neovascular age-related macular degeneration. A comprehensive examination using ultrasound, optical coherence tomography, and fundus autofluorescence revealed changes characteristic of vitreoretinal lymphoma. Molecular genetic analysis of the vitreous body showed the presence of a MYD88 gene mutation and B-cell clonality by immunoglobulin heavy chain (IGH) gene rearrangement tests, which confirmed the diagnosis.

Multimodal imaging observation of primary vitreous cysts.

BACKGROUND: Primary vitreous cyst is a clinical variant delineated by the existence of a vesicle within the vitreous cavity from birth. This particular disease tends to be uncommon, and the underlying mechanisms contributing to its pathogenesis remain obscure. CASE PRESENTATION: A 37-year-old male patient manifested blurry vision and floaters in his right eye, a symptomology first noticed three months prior. Upon slit-lamp examination, a pigmented, round, 1 papilla diameter-sized mass was discerned floating in the vitreous. A meticulous examination of the floaters was conducted using an array of multimodal imaging techniques. Other potential conditions, including cysticercosis, toxoplasmosis, and tumors, were conclusively excluded through comprehensive diagnostic tests such as blood examinations, liver ultrasound, and cranial magnetic resonance imaging (MRI), resulting in the diagnosis of a primary vitreous cyst. The patient did not report any other discomforts and did not receive any subsequent interventions or treatments. CONCLUSION: We furnish an exhaustive case report of a patient diagnosed with a primary vitreous cyst. The incorporation of multimodal images in the characterization of the disease anticipates facilitating an enriched comprehension by medical practitioners.

Influence of Vitreous Cortex Remnants on Normal Retinal Anatomy in Eyes with Primary Rhegmatogenous Retinal Detachment.

PURPOSE: To investigate the influence of vitreous cortex remnants (VCRs) removal on normal retinal anatomy in eyes with rhegmatogenous retinal detachment (RRD). DESIGN: Prospective cohort study. SUBJECTS: Patients with primary RRD operated with pars plana vitrectomy (PPV). METHODS: Blue fundus autofluorescence and spectral-domain OCT were obtained preoperatively, and at 1 and 6 months after operation. MAIN OUTCOME MEASURES: Primary outcomes: rate of retinal displacement and outer retinal folds (ORFs) at 1 month after operation. SECONDARY OUTCOMES: continuity of the external limiting membrane (ELM) and ellipsoid zone (EZ), and the logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) at 6 months after operation. RESULTS: One hundred three eyes were included. Intraoperatively, peripheral VCRs (pVCRs) were found in 42 eyes (40.8%) and successfully peeled off from ≥2 quadrants in 37 eyes. Macular VCRs (mVCRs) were detected in 37 (35.9%) and successfully peeled off in 29 eyes. At the end of operation 44.7% and 55.3% of the eyes were tamponaded with 20% sulfur hexafluoride gas and silicone oil 1000 centistokes, respectively. The only variable significantly associated with displacement was the use of gas tamponade versus silicone oil (P = 0.001), whereas no significant association was found between retinal displacement and pVCRs (P = 0.58) or number of quadrants from which pVCRs were peeled off (P = 0.39). At 1 month postoperatively, ORFs were globally detected in 24 eyes (23.3%). Regression analysis showed a direct correlation between ORFs and the intraoperative detection of mVCRs (P = 0.02) and an indirect correlation between ORFs and mVCRs peeling (P = 0.004). Macular VCRs peeling did not influence the continuity of ELM and EZ at the 6-month follow-up (FU). Intraoperative absence of mVCRs (P = 0.0016) and peeling of mVCRs (P = 0.003) were associated with logMAR BCVA ≤0.3 at the 6-month FU. CONCLUSIONS: Peeling of pVCRs did not seem to influence the rate of retinal displacement, whereas peeling of mVCRs was associated with a reduced risk of developing ORFs without detrimental effect on the continuity of ELM/EZ at 6-month FU. The patients without mVCRs detected intraoperatively, or who underwent mVCRs peeling during operation, showed a significantly better visual acuity at the 6-month FU. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.