Posterior Vitreous Detachment: Methods for Detection

Symptomatic Vitreous Opacities: Exploring the Mismatch between Clinical Observation of Vitreous Alterations and Self-Reported Symptoms

Objectives: To assess the mismatch between the clinical observation of vitreous alterations and self-reported symptoms in young patients complaining of symptomatic vitreous opacities (SVO). Methods: The ophthalmic medical records of young patients presenting primarily with SVO were retrospectively evaluated. Symptoms severity was assessed using a questionnaire. The status of the vitreous body was examined with indirect ophthalmoscopy at the slit-lamp and classified according to an ad hoc severity scale. Results: Sixty eyes of thirty otherwise healthy patients (median age: 32.5 (IQR: 29.0-37.0) years old) complaining of SVO (median duration: 38 months; interquartile range: 18-84 months) were enrolled. SVO was rated as severe by 50% of participants, affecting all the activities explored in the questionnaire. Twenty-three patients (76.6%) reported SVO-related depression and/or anxiety, for which eleven patients (36.6%) were or had been using medication. Fifty-eight eyes (96.6%) showed no evidence of (or minimal) vitreous opacity, while two eyes (3.3%) were found to have significant vitreous opacity. No significant inter-gender differences (p > 0.05) and no significant differences (p > 0.05) were found between the severity of vitreous opacity and patients' reported symptoms nor with their psychological status and medication use. Conclusions: Severe discomfort related to the perception of vitreous floaters exists in young patients whose vitreous gel examination is unremarkable or shows only minor alterations. We believe this discrepancy can be explained by optical anisotropy; significant forward-scattering of light, which results in floater symptoms; and reduced back reflection, which limits the clinical observation.

Degradation of Photopic and Mesopic Contrast Sensitivity Function in High Myopes With Partial Posterior Vitreous Detachment

Purpose

The purpose of this study was to evaluate the effects of posterior vitreous detachment (PVD) on visual quality in patients with high myopia, as well as investigate the associated factors of photopic and mesopic contrast sensitivity function (CSF) in high myopia.

Methods

Visual quality was comprehensively assessed in patients with high myopia. Visual acuity, contrast sensitivity (CS) at four spatial frequencies (3, 6, 12, and 18 cycles per degree [c.p.d.]) under photopic and mesopic conditions, as well as the modulation transfer function cutoff value (MTFcutoff), the objective scatter index (OSI), the Strehl ratio (SR), and internal aberrations, were measured in this cross-sectional study.

Results

This study included 94 eyes from 47 subjects with bilateral high myopia, including 23 eyes with complete PVD (cPVD), 21 eyes with partial PVD (pPVD), and 50 eyes without PVD (nPVD). There was no significant difference in visual quality between the cPVD group and the nPVD group. Whereas in eyes with pPVD, there was a degradation of overall photopic CSF (versus nPVD, P = 0.048), photopic CS at 3 c.p.d. (versus cPVD, P = 0.009 and versus nPVD, P = 0.032), photopic CS at 18 c.p.d. (versus nPVD, P = 0.033), overall mesopic CSF (versus nPVD, P = 0.033), and secondary astigmatism (versus cPVD, P = 0.044). Under photopic conditions, the factors affecting CSF were pPVD and SR, whereas the factors affecting mesopic CSF were pPVD, OSI, and ganglion cell-inner plexiform layer thickness.

Conclusions

The pPVD impaired visual quality in patients with high myopia compared to nPVD or cPVD, and pPVD could be a factor explaining CSF at both photopic and mesopic illumination.

Translational Relevance

Clinicians need to closely monitor patients with high myopia with pPVD due to the potential decline in visual quality and the development of vitreoretinal disorders.

Evaluation of epiretinal membrane formation after scleral buckling for treating rhegmatogenous retinal detachment: En face optical coherence tomography image-based study

PURPOSE

To assess epiretinal membrane (ERM) formation, severity, and the associated risk factors after scleral buckling using en face optical coherence tomography (OCT) images.

METHODS

Medical records of 61 consecutive patients (66 eyes) with rhegmatogenous retinal detachment who underwent scleral buckling were retrospectively reviewed. Posterior vitreous detachment (PVD) was determined based on B-scan OCT images. En face OCT images were used to visualize the ERM and retinal folds. ERM formation was identified by comparing en face images pre- and post-surgery. The maximum depth of the retinal folds (MDRF) was measured using en face imaging to objectively assess traction strength.

RESULTS

ERM formation occurred in 15 (22.7%) eyes at the final visit; the foveal pit was preserved in all cases. Parafoveal retinal folds were present in 5 (7.6%) eyes, with a mean MDRF of 21.8 ± 12.6 µm. No significant difference was observed in best-corrected visual acuity (logarithm of the minimal angle of resolution) between the ERM formation (-0.019 ± 0.128) and non-ERM formation (-0.001 ± 0.213) groups at the final visit (P = 0.593; Mann-Whitney U test). Multivariate logistic regression analysis revealed that older age and the presence of PVD were significant risk factors for ERM formation (odds ratio 1.07, 95% confidence interval 1.01-1.14, P = 0.032; odds ratio 5.26, 95% confidence interval 1.06-26.10, P = 0.042; respectively).

CONCLUSION

ERM occurred in 22.7% of cases but was mild and did not affect visual acuity. Older age and the presence of PVD are risk factors for ERM formation.

Risk Factors for the Development of Fellow Eye Horseshoe Retinal Tears Following Horseshoe Retinal Tear in the Presenting Eye

BACKGROUND

This study investigated factors associated with fellow eye horseshoe retinal tear (HST) development in consecutive patients with a presenting eye HST.

MATERIALS AND METHODS

Medical records were reviewed for patients with initial HSTs between 2015 and 2017 and 24 factors were analyzed. Logistic regression was used to assess factors associated with fellow eye HST development.

RESULTS

In total, 242 patients with an HST were identified with mean follow-up of 68.3 months. Four associations with fellow eye HST development were identified: (1) presence of fellow eye lattice degeneration, (2) subsequent presenting eye HSTs, (3) fellow eye vitreous hemorrhage at presenting eye HST occurrence, (4) OCT-determined stage 3 fellow eye posterior vitreous detachment at presenting eye HST occurrence.

CONCLUSION

Four clinical findings associated with fellow eye HST development following presenting eye HST were identified. These factors may be important considerations during management patients with HST. [Ophthalmic Surg Lasers Imaging Retina 2023;54:338-345.].

Automated Detection of Posterior Vitreous Detachment on OCT Using Computer Vision and Deep Learning Algorithms

Objective

To develop automated algorithms for the detection of posterior vitreous detachment (PVD) using OCT imaging.

Design

Evaluation of a diagnostic test or technology.

Subjects

Overall, 42 385 consecutive OCT images (865 volumetric OCT scans) obtained with Heidelberg Spectralis from 865 eyes from 464 patients at an academic retina clinic between October 2020 and December 2021 were retrospectively reviewed.

Methods

We developed a customized computer vision algorithm based on image filtering and edge detection to detect the posterior vitreous cortex for the determination of PVD status. A second deep learning (DL) image classification model based on convolutional neural networks and ResNet-50 architecture was also trained to identify PVD status from OCT images. The training dataset consisted of 674 OCT volume scans (33 026 OCT images), while the validation testing set consisted of 73 OCT volume scans (3577 OCT images). Overall, 118 OCT volume scans (5782 OCT images) were used as a separate external testing dataset.

Main Outcome Measures

Accuracy, sensitivity, specificity, F1-scores, and area under the receiver operator characteristic curves (AUROCs) were measured to assess the performance of the automated algorithms.

Results

Both the customized computer vision algorithm and DL model results were largely in agreement with the PVD status labeled by trained graders. The DL approach achieved an accuracy of 90.7% and an F1-score of 0.932 with a sensitivity of 100% and a specificity of 74.5% for PVD detection from an OCT volume scan. The AUROC was 89% at the image level and 96% at the volume level for the DL model. The customized computer vision algorithm attained an accuracy of 89.5% and an F1-score of 0.912 with a sensitivity of 91.9% and a specificity of 86.1% on the same task.

Conclusions

Both the computer vision algorithm and the DL model applied on OCT imaging enabled reliable detection of PVD status, demonstrating the potential for OCT-based automated PVD status classification to assist with vitreoretinal surgical planning.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

UTILIZATION OF SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY TO IDENTIFY POSTERIOR VITREOUS DETACHMENT IN PATIENTS WITH RETINAL DETACHMENT

PURPOSE

To compare posterior vitreous detachment (PVD) identification rate between clinical examination versus spectral domain optical coherence tomography in patients with retinal detachment (RD).

METHODS

Data from the Primary Retinal Detachment Outcomes Study were used for this retrospective cross-sectional study of 506 patients. Spectral domain optical coherence tomography scans were reviewed to detect the separation of the posterior hyaloid face from the retina and the optic nerve on all 31 raster cuts of a 30 × 30 scan. Statistical analysis was performed to compare spectral domain optical coherence tomography-identified PVD with PVD identified on slit-lamp biomicroscopy.

RESULTS

There was a significant difference in the rate of PVD identification by clinical examination versus spectral domain optical coherence tomography in patients with RD. Clinical examination identified 51.58% of patients with PVD, whereas spectral domain optical coherence tomography identified 78.42% of patients with PVD. In patients with macula-on RD, 61.68% were found to have PVD on clinical examination versus 83.90% by imaging. Spectral domain optical coherence tomography identified larger number of PVD in patients with macula-off RD compared with clinical examination, 46.28% versus 75.43%, respectively. There was low agreement between the two methods (kappa score = 0.137). There was a significant difference in surgical procedure type chosen in those with versus without PVD.

CONCLUSION

Knowledge about the posterior hyaloid anatomy is important before undergoing RD repair. Spectral domain optical coherence tomography can better identify PVD than clinical examination in patients with RD.

Vitreous and Vision Degrading Myodesopsia

Macromolecules comprise only 2% of vitreous, yet are responsible for its gel state, transparency, and physiologic function(s) within the eye. Myopia and aging alter collagen and hyaluronan association causing concurrent gel liquefaction and fibrous degeneration. The resulting vitreous opacities and collapse of the vitreous body during posterior vitreous detachment are the most common causes for the visual phenomenon of vitreous floaters. Previously considered innocuous, the vitreous opacities that cause floaters sometimes impact vision by profoundly degrading contrast sensitivity function and impairing quality-of-life. While many people adapt to vitreous floaters, clinically significant cases can be diagnosed with Vision Degrading Myodesopsia based upon echographic assessment of vitreous structure and by measuring contrast sensitivity function. Perhaps due to the ubiquity of floaters, the medical profession has to date largely ignored the plight of those with Vision Degrading Myodesopsia. Improved diagnostics will enable better disease staging and more accurate identification of severe cases that merit therapy. YAG laser treatments may occasionally be slightly effective, but vitrectomy is currently the definitive cure. Future developments will usher in more informative diagnostic approaches as well as safer and more effective therapeutic strategies. Improved laser treatments, new pharmacotherapies, and possibly non-invasive optical corrections are exciting new approaches to pursue. Ultimately, enhanced understanding of the underlying pathogenesis of Vision Degrading Myodesopsia should result in prevention, the ultimate goal of modern Medicine.