Vitreoschisis

[Epiretinal membrane: diagnostics, indications and surgical treatment]

An epiretinal membrane (ERM) is a frequently occurring disease affecting the macula, which can be associated with visual impairment and metamorphopsia, depending on the severity and location. A distinction is made between an idiopathic form caused by age-related changes of the vitreous body and a secondary form associated with diseases of the posterior segment. The development of fibrocellular epiretinal membranes formed by dedifferentiation of intraretinal and extraretinal cells at the level of the vitreomacular interface plays a major role in the pathogenesis. The diagnostics and indications for surgical treatment of ERM are based on the visual acuity, evidence of metamorphopsia, ophthalmoscopic findings and optical coherence tomography (OCT) of the macula. In addition to the possibility of observation of the course where benign spontaneous courses are not uncommon, pars plana vitrectomy (PPV) with peeling of the ERM and internal limiting membrane (ILM) to prevent recurrences is the treatment of choice in symptomatic patients. The prognosis after surgical treatment is very good. In approximately two thirds of the cases, an improvement in visual acuity and/or a reduction of metamorphopsia can be achieved, with a number of predictive, primarily OCT-based factors enabling a prediction of the functional prognosis. Comprehensive patient education regarding the generally long duration of postoperative rehabilitation and the possibility of persistent symptoms or visual deterioration despite successful membrane removal is essential.

IMAGING RHEGMATOGENOUS RETINAL LESIONS AND PERIPHERAL VITREORETINAL INTERFACE WITH WIDEFIELD OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

Analyze the peripheral vitreoretinal interface with widefield optical coherence tomography.

METHODS

Retrospective chart analysis and widefield optical coherence tomography in 120 consecutive cases of rhegmatogenous pathology.

RESULTS

There were 166 lesions in 120 eyes, including 106 horseshoe tears, 22 operculated holes, 30 nonoperculated holes, six giant tears, and two peripheral lamellar defects followed for 6.1 ± 1.2 months. Posterior vitreous detachment was present in all eyes (101/101, 100%) with tears and operculated holes, but only in 5/19 eyes (26.3%) with nonoperculated holes ( P < 0.001). Axial vitreous traction was evident at the anterior edge of horseshoe tears (106/106, 100%), but not the posterior border (18/106, 17%, P < 0.001). Operculated holes located posterior to the vitreous base were free from vitreous traction, displaying a morphology similar to the macular hole. Nonoperculated holes were farther anterior with signs of tangential traction in 23/30 (76.7%) cases. Peripheral vitreoschisis was more often associated with nonoperculated holes (25/30, 83.3%), than horseshoe tears (17/106, 16%; P < 0.001). Horseshoe tears and nonoperculated holes were more often associated with retinal detachment (58/106 [54.7%] and 15/30 [50%], respectively) than operculated holes (5/22, 22.7%), P = 0.023.

CONCLUSION

Peripheral vitreoretinal interactions are similar to vitreomaculopathies, with axial and vitreoschisis-related tangential traction playing different roles in different rhegmatogenous pathologies. Peripheral optical coherence tomography improves understanding of pathophysiology and risks of retinal detachment.

Prevalence of vitreoschisis-induced vitreous cortex remnants over the peripheral retinal surface in eyes undergoing vitrectomy for primary rhegmatogenous retinal detachment

PURPOSE

Unremoved vitreoschisis-induced vitreous cortex remnants over the peripheral retinal surface posterior to the vitreous base (pVCR) may increase the risk of surgical failure after primary rhegmatogenous retinal detachment (RRD) repair. The purpose of this study was to validate our previous findings on pVCR prevalence during vitrectomy for RRD and to examine their association with proliferative vitreoretinopathy (PVR) and surgical failure.

METHODS

Prospective observational multisurgeon study of 100 eyes of 100 consecutive patients who underwent vitrectomy for RRD by one of four vitreoretinal surgeons. Collected data included detected pVCR and known PVR risk factors. Pooled analysis with our previous retrospective study (251 eyes of 251 patients) was also performed.

RESULTS

Initial PVR (≥C) was present and removed in 6/100 (6%) patients, pVCR were detected in 36/100 (36%) patients, pVCR were removed in 30/36 (83%) patients with pVCR, and 4/36 (11%) patients with pVCR were high myopes (≤-6D). Six per cent (6/100) developed a retinal redetachment, of which 3/6 (50%) had initial PVR (≥C). Surgical failure rates in eyes with and without pVCR were 17% (6/36) and 0% (0/64), respectively. In eyes with pVCR and surgical failure, pVCR were not or not completely removed during the first surgery. Overall analysis showed that pVCR were statistically significantly associated with PVR.

CONCLUSIONS

This study confirms our previous findings: a pVCR prevalence of around 35% and an association between pVCR, PVR formation and surgical failure in patients undergoing vitrectomy for RRD. More research is needed to determine which patients would benefit most from pVCR removal.

Vitreous Cortex Remnants Removal With Beveled Vitrectomy Probe During Vitrectomy For Primary Rhegmatogenous Retinal Detachment

PURPOSE

To introduce a new surgical technique with a beveled vitrectomy probe for the removal of peripheral vitreous cortex remnants (VCR) in primary rhegmatogenous retinal detachment (RRD).

METHODS

This study was a retrospective case series. From September 2019 to June 2022, 54 patients with complete or partial posterior vitreous detachment who underwent vitrectomy for primary RRD by a single surgeon were enrolled.

RESULTS

After staining the vitreous with triamcinolone acetonide, the presence of VCR was assessed in detail. If VCR were present, the macular VCR were removed using surgical forceps, and then, a free flap of peripheral VCR was used as a handle for removing peripheral VCR using the beveled vitrectomy probe. Of the total patients, the presence of VCR was confirmed in 16 patients (29.6%). There were no intraoperative or postoperative complications, except for retinal redetachment caused by proliferative vitreoretinopathy, that occurred in only one eye (1.9%).

CONCLUSION

Using a beveled vitrectomy probe was a practical solution for removing VCR during RRD vitrectomy because additional instruments were not needed and risk of iatrogenic retinal damage was low.

Biomarkers of Vitreous Cortex Remnants in Eyes With Primary Rhegmatogenous Retinal Detachment

Purpose

The purpose of this study was to identify pre-operative biomarkers of vitreous cortex remnants (VCRs) in eyes with rhegmatogenous retinal detachment (RRD).

Methods

Prospective case series of 103 eyes treated with pars plana vitrectomy (PPV) to repair RRD. Pre-operatively, optical coherence tomography (OCT) and B-scan ultrasonography (US) were used to study the vitreo-retinal interface and vitreous cortex status. If detected during PPV, VCRs were removed. Images acquired pre-operatively were compared with intra-operative findings and with postoperative OCT images taken at 1, 3, and 6 months of follow-up. Multivariate regression analyses were performed to determine associations between VCRs and pre-operative variables.

Results

The presence of VCRs at the macula (mVCRs) and at the periphery (pVCRs), was ascertained intra-operatively in 57.3% and 53.4% of the eyes, respectively. Pre-operatively, a preretinal hyper-reflective layer (PHL) and a saw-toothed aspect of the retinal surface (SRS) were identified with OCT in 73.8% and 66% of the eyes, respectively. US sections showed a vitreous cortex running close and parallel to the detached retina upon static and kinetic examination (the "lining sign") in 52.4% of the cases. Multivariate regression analyses showed an association between PHL and SRS and intra-operative evidence of mVCRs (P = 0.003 and < 0.0001, respectively) and between SRS and "lining sign" and pVCRs (P = 0.0006 and 0.04, respectively).

Conclusions

PHL and SRS on OCT and the "lining sign" on US appear to be useful pre-operative biomarkers of the intra-operative presence of VCRs.

Translational Relevance

Preoperative identification of VCRs biomarkers may help to plan the operating strategy in eyes with RRD.

Is There a Link Between Vitreous Cortex Remnants and Anatomic Outcome of Vitrectomy for Primary Rhegmatogenous Retinal Detachment?

Purpose

To study the anatomic outcome of leaving vitreous cortex remnants (VCR) during pars plana vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD).

Methods

The study comprised patients with RRD who had PPV by a single surgeon between January 2019 and December 2020 and followed for 6 months. After intravitreal injection of triamcinolone acetonide, the topographic pattern of VCR at the periphery (p) and macula (m) was divided into 2 types by extent: complete or 4 quadrants (pVCR4Q), and between 2 and 4 quadrants ≥2 quadrants (pVCR>2Q), or by location >1 inferior retinal quadrant (pVCR>1InfQ), and at the macula (mVCR). Anatomical failure or retinal re-detachment within 6 months after surgery was the primary outcome measures. The occurrence of grade C proliferative vitreoretinopathy (PVR) and epiretinal membrane (ERM) were used as secondary outcome indicators.

Results

A 6-month prospective follow-up was performed on 103 patients. pVCR4Q was detected in 31 eyes, pVCR>2Q in 40 eyes, pVCR>1InfQ in 40 eyes and mVCR in 54 eyes. Recurrent RRD developed in 9 (8.7%) eyes, PVR grade C in 6 (5.8%) eyes and ERM in 11 (10.7%) eyes. According to multivariate regression analysis, the existence of any type of VCR did not correlate with anatomical failure, PVR or ERM.

Conclusion

The initial success rate of PPV and the growth of PVR or ERM do not appear to be impacted by keeping VCR.

3-D OCT imaging of hyalocytes in partial posterior vitreous detachment and vaso-occlusive retinal disease

Purpose

To describe the spatial distribution and morphologic characteristics of macrophage-like cells called hyalocytes in the posterior vitreous cortex of a patient with unilateral partial posterior vitreous detachment (PVD) using coronal plane en face optical coherence tomography (OCT).

Observations

A 54-year-old male with sickle cell disease (HbSC genotype) presented with a partial PVD in one eye. Rendered volumes of a slab extending from 600 μm to 3 μm anterior to the inner limiting membrane (ILM) revealed hyperreflective foci in the detached posterior vitreous cortex suspended anterior to the macula, likely representing hyalocytes. In the fellow eye without PVD, hyperreflective foci were located 3 μm anterior to the ILM. The morphology of the cells in the eye with PVD varied between a ramified state with multiple elongated processes and a more activated state characterized by a plump cell body with fewer retracted processes. In the same anatomical location, the hyperreflective foci were 10-fold more numerous in the patient with vaso-occlusive disease than in an unaffected, age-matched control.

Conclusions and Importance

Direct, non-invasive, and label-free techniques of imaging cells at the vitreoretinal interface and within the vitreous body is an emerging field. The findings from this case report suggest that coronal plane en face OCT can be used to provide a detailed and quantitative characterization of cells at the human vitreo-retinal interface in vivo. Importantly, this case report demonstrates that 3D-OCT renderings can enhance visualization of these cells in relation to the ILM, which may provide clues concerning the identity and contribution of these cells to the pathogenesis of vitreo-retinal diseases.

Increased intravitreal glucose in rhegmatogenous retinal detachment

PURPOSE

Altered glucose metabolism, along with low-grade inflammation, has been proposed to be involved in retinal detachment (RD)-induced cone loss. Here, we assessed intravitreal glucose and cytological profile in patients with macula-off RD.

METHODS

Glucose concentration was analysed in vitreous samples from 137 non-diabetic patients undergoing vitrectomy for either primary macula-off RD (n = 73) or epiretinal membrane (ERM; n = 64). Cellularity was assessed in vitreous cytospin preparations by a semi-quantitative immunostaining approach.

RESULTS

Intravitreal glucose concentration was higher in the RD group (2.28 mmol.L-1 n =73 vs 1.6 mmol.L-1 n = 64; p < 0.0001). Overall cellularity and density of macrophages were significantly higher in the vitreous of RD patients (respectively p = 0.003 and p < 0.0001). Among the RD patients, intravitreal glucose concentration correlated with macrophages density (p = 0.002): its levels remained significantly higher in eyes in which macrophages were innumerable compared to lower macrophages densities RD eyes (p = 0.0095).

CONCLUSIONS

We observed a strong relationship between intravitreal glucose concentration and vitreous macrophage density. Additional indicators for vitreous glycation and low-grade inflammation should be further studied.

Effectiveness of intraoperative optical coherence tomography on vitrectomy for proliferative diabetic retinopathy

PURPOSE

We sought to verify the effect of intraoperative optical coherence tomography (iOCT) on vitrectomy for the treatment of proliferative diabetic retinopathy (PDR).

STUDY DESIGN

Retrospective study.

METHODS

We reviewed 178 eyes with PDR treated with 25-gauge vitrectomy by a single surgeon between April 2013 and December 2017. In total, 98 eyes of 77 patients with PDR (mean age, 52.5 ± 11.7 years) treated with vitrectomy using iOCT (iOCT group) and 80 eyes of 60 patients with PDR (mean age, 53.1 ± 10.9 years) treated without iOCT (non-iOCT group) were included in the study. To determine the effects of combining vitrectomy with iOCT, a comparison was made of patients treated with this combination and patients treated with vitrectomy without iOCT. The effects of these treatments were assessed on the basis of intraoperative complications, reoperation ratios, postoperative complications, operation times, and postoperative visual acuity.

RESULTS

The operation time was significantly reduced for the iOCT group (72.9 ± 23.9 min) when compared with the non-iOCT group (91.3 ± 31.2 min) (P = .001). The incidences of intraoperative complications, reoperation, and postoperative complications did not differ significantly between the 2 groups (P = .542, 0.258, and 0.860 respectively). Six months after surgery, the postoperative visual acuity did not differ significantly between the 2 groups (P = .508). Multiple linear regression analysis revealed that the operation time was significantly correlated with iOCT (beta [standard partial regression coefficient] = - 0.28, P < .001), the fibrovascular proliferative membrane (beta = 0.17, P = .009), cataract surgery (beta = 0.22, P = .016), preoperative retinal photocoagulation (beta = - 0.14, P = .021), intraoperative complications (beta = 0.16, P = .023), and posterior vitreous detachment (beta = - 0.14, P = .04).

CONCLUSION

Use of iOCT reduced the operation time without affecting the incidence rates of intraoperative and postoperative complications, reoperation ratios, or postoperative visual acuities in patients who underwent vitreous surgery for PDR.

Non-vasogenic cystoid maculopathies

Besides cystoid macular edema due to a blood-retinal barrier breakdown, another type of macular cystoid spaces referred to as non-vasogenic cystoid maculopathies (NVCM) may be detected on optical coherence tomography but not on fluorescein angiography. Various causes may disrupt retinal cell cohesion or impair retinal pigment epithelium (RPE) and Müller cell functions in the maintenance of retinal dehydration, resulting in cystoid spaces formation. Tractional causes include vitreomacular traction, epiretinal membranes and myopic foveoschisis. Surgical treatment does not always allow cystoid space resorption. In inherited retinal dystrophies, cystoid spaces may be part of the disease as in X-linked retinoschisis or enhanced S-cone syndrome, or occur occasionally as in bestrophinopathies, retinitis pigmentosa and allied diseases, congenital microphthalmia, choroideremia, gyrate atrophy and Bietti crystalline dystrophy. In macular telangiectasia type 2, cystoid spaces and cavitations do not depend on the fluid leakage from telangiectasia. Various causes affecting RPE function may result in NVCM such as chronic central serous chorioretinopathy and paraneoplastic syndromes. Non-exudative age macular degeneration may also be complicated by intraretinal cystoid spaces in the absence of fluorescein leakage. In these diseases, cystoid spaces occur in a context of retinal cell loss. Various causes of optic atrophy, including open-angle glaucoma, result in microcystoid spaces in the inner nuclear layer due to a retrograde transsynaptic degeneration. Lastly, drug toxicity may also induce cystoid maculopathy. Identifying NVCM on multimodal imaging, including fluorescein angiography if needed, allows guiding the diagnosis of the causative disease and choosing adequate treatment when available.

Utility of Removal of Vitreous Cortex Remnants during Vitrectomy for Primary Rhegmatogenous Retinal Detachment Repair

PURPOSE

To investigate the prevalence of vitreous cortex remnants (VCR) in primary rhegmatogenous retinal detachment (RRD) and the utility of VCR removal using diamond-dusted membrane scrapers (DDMS) during pars plana vitrectomy (PPV).

METHODS

One hundred and eighty-seven eyes (187 consecutive patients) were retrospectively studied. We evaluated the prevalence of VCR on the retinal surface extending from the macula to outside the vascular arcade in eyes that underwent PPV for primary RRD by a single surgeon between July 2014 and February 2021. The VCR outside the vascular arcade was completely removed using a DDMS. Preoperative factors and surgical outcomes were compared between eyes with VCR removed intraoperatively to those without VCR.

RESULTS

VCR was present and removed (group A) in 86 (46%) eyes and absent (group B) in 101 (54%) eyes. Patients with VCR were significantly older than those without (P = 0.006). The preoperative BCVA (logMAR) tended to be worse in group A (1.23 ± 0.92 [Snellen equivalent, 20/340]) than in group B (1.03 ± 0.89 [20/214]), however, the difference was not statistically significant (P = 0.095). There were no between-group differences in postoperative BCVA (group A; 0.44 ± 0.54 [20/55]; group B; 0.42 ± 0.50 [20/53]; P = 0.38). Single surgery anatomic success (group A; 90%, group B; 91%, P = 0.573) and the incidence of postoperative PVR (group A; 9%, group B; 6%, P = 0.554) were comparable between the groups.

CONCLUSIONS

Nearly half of the patients had VCR, which was more likely to occur in older patients. VCR removal resulted in favorable functional and anatomic outcomes similar to those in eyes without any VCR in patients with RRD.

Novel insights into the pathophysiology of proliferative vitreoretinopathy: The role of vitreoschisis-induced vitreous cortex remnants

PURPOSE

We previously hypothesized a causal relationship between vitreoschisis-induced vitreous cortex remnants (VCR) and the development of proliferative vitreoretinopathy (PVR). This study aims to substantiate this association through histopathological analysis of surgical specimens in support of strategies to improve therapeutic outcomes.

METHODS

A descriptive, prospective, non-consecutive case series. Histopathological and immunohistochemical analyses were performed on membranes removed from the peripheral retinal surface during initial vitrectomy for primary rhegmatogenous retinal detachment (RRD) (n = 11) or recurrent retinal detachment (n = 12). The clinical aspect of the membranes ranged from loose-meshed membranes visualized with triamcinolone to more fibrotic membranes stained with trypan blue.

RESULTS

Consistent with the clinical presentation, histopathological analysis revealed membranes with different area characteristics. Paucicellular lamellar collagen-rich areas, suggestive of VCR, appeared to transition to areas of increased cellularity and eventually more fibrotic areas of low cellularity. Five different area characteristics could be identified that seemed to correspond to five histopathological stages in PVR formation, with lamellar VCR collagen acting as an essential precondition: 1. Lamellar collagen, low cellularity (hyalocytes). 2. Lamellar collagen, increased cellularity (hyalocytes, glial cells). 3. Lamellar collagen, high cellularity (macrophages, glial cells, RPE-cells). 4. Early fibrosis, decreased cellularity (myofibroblasts). 5. Fibrosis, low cellularity (myofibroblasts).

CONCLUSION

These findings confirm the role of VCR in preretinal PVR formation posterior to the vitreous base. We propose that the presence of VCR over the retinal surface should be qualified as a risk factor for PVR formation. Detection and adequate removal of VCR may improve the success rate of vitreoretinal surgeries.

Mechanistic Insights into the Pathogenesis of Proliferative and Nonproliferative Vitreomacular Traction

PURPOSE

To describe the vitreoretinal interface in vitreomacular traction (VMT) by using novel optical coherence tomography (OCT) methods; wide-angle montage, and pseudomotion OCT imaging systems.

DESIGN

Observational case series.

METHODS

Wide-angle montage OCT images of horizontal and vertical scans through the fovea were acquired in 50 eyes of 46 consecutive patients with VMT. Baseline fundus scans were obtained. These were followed by scans acquired with an eye-tracking system performed immediately after vertical and horizontal eye movements. Three scans were then superimposed to compare changes in the contour and position of the posterior vitreous.

RESULTS

The subjects were classified as VMT with ("proliferative"; 48.0%) and without ("nonproliferative"; 52.0%) thickened posterior vitreous. Epiretinal membrane was observed in 26.9% of nonproliferative and 95.8% of proliferative VMT eyes (P = 3.6 × 10^-7). No eye of proliferative and 57.7% of nonproliferative VMT eyes had wavy contoured posterior vitreous (P = 4.0 × 10^-6). None with proliferative VMT, but 91.7% of nonproliferative VMT eyes, showed motion induced changes of posterior vitreous following eye movement (P = 2.0 × 10^-8). The posterior vitreous detachment extended beyond the scanned area in 34.6% of nonproliferative and 8.3% of proliferative VMT eyes (P = .040).

CONCLUSIONS

By dynamically evaluating the vitreoretinal interface of patients with VMT, the static contraction forces of a thickened posterior vitreous at the macula are implicated in proliferative VMT. This contractile force is not strongly implicated in the majority of VMT eyes with nontaut and more mobile vitreous (nonproliferative VMT). VMT and its associated complications are determined by at least 2 different pathophysiological mechanisms.

Single-Cell Protein and Transcriptional Characterization of Epiretinal Membranes From Patients With Proliferative Vitreoretinopathy

Purpose

Proliferative vitreoretinopathy (PVR) remains an unresolved clinical challenge and can lead to frequent revision surgery and blindness vision loss. The aim of this study was to characterize the microenvironment of epiretinal PVR tissue, in order to shed more light on the complex pathophysiology and to unravel new treatment options.

Methods

A total of 44 tissue samples were analyzed in this study, including 19 epiretinal PVRs, 13 epiretinal membranes (ERMs) from patients with macular pucker, as well as 12 internal limiting membranes (ILMs). The cellular and molecular microenvironment was assessed by cell type deconvolution analysis (xCell), RNA sequencing data and single-cell imaging mass cytometry. Candidate drugs for PVR treatment were identified in silico via a transcriptome-based drug-repurposing approach.

Results

RNA sequencing of tissue samples demonstrated distinct transcriptional profiles of PVR, ERM, and ILM samples. Differential gene expression analysis revealed 3194 upregulated genes in PVR compared with ILM, including FN1 and SPARC, which contribute to biological processes, such as extracellular matrix (ECM) organization. The xCell and IMC analyses showed that PVR membranes were composed of macrophages, retinal pigment epithelium, and α-SMA-positive myofibroblasts, the latter predominantly characterized by the co-expression of immune cell signature markers. Finally, 13 drugs were identified as potential therapeutics for PVR, including aminocaproic acid and various topoisomerase-2A inhibitors.

Conclusions

Epiretinal PVR membranes exhibit a unique and complex transcriptional and cellular profile dominated by immune cells and myofibroblasts, as well as a variety of ECM components. Our findings provide new insights into the pathophysiology of PVR and suggest potential targeted therapeutic options.

Surgical technique for removing vitreous cortex remnants using a diamond-dusted membrane scraper

PURPOSE

The purpose of this paper is to present a new surgical technique to remove vitreous cortex remnants.

METHODS

Non-consecutive retrospective interventional case series.

RESULTS

When the posterior vitreous is split, its outermost layer may remain attached to the retina, developing vitreoschisis-induced vitreous cortex remnants (VCR). Their role in macular pathology etiopathogenesis has been well documented; however, recently, it has been proposed that VCR also play a crucial role in proliferative vitreoretinopathy and consequent retinal redetachment. The prevalence of VCR is underestimated because triamcinolone acetonide is not routinely used for vitreous staining. Vitreous cortex remnants (VCR) removal is challenging, and several surgical techniques have been proposed. However, they require sclerotomy enlargement, material that may not be readily available, and manual fashioning. Alternatively, a diamond-dusted membrane scraper (DDMS), already widely used in macular pathology treatment, can follow the contour of the retina, as it is a silicone tube, and remove VCR with its abrasive tip. A DDMS may also be introduced in the vitreous cavity through a standard trocar. Finally, the use of a DDMS provides predictable feedback, making the learning curve short. In this case series, 34 eyes affected by primary rhegmatogenous retinal detachment were enrolled. The retinal redetachment rate was 2.9% at six months of follow-up, below the average literature value of 21%. No adverse events were reported.

CONCLUSION

A DDMS can be suitable for use in VCR removal, although further studies are warranted to understand the indications and extent of this surgical technique for improving the management of rhegmatogenous retinal detachment.

Vitreoschisis and retinal detachment: New insight in proliferative vitreoretinopathy

PURPOSE

To assess the occurrence of peripheral vitreoschisis-induced vitreous cortex remnants (p-VCRs) in primary rhegmatogenous retinal detachment (RD) and investigate whether the presence of p-VCRs results in a greater risk of RD recurrence, secondary to Proliferative Vitreoretinopathy (PVR) development after pars plana vitrectomy (PPV).

METHODS

Patients who underwent PPV for primary rhegmatogenous RD between January 2016 and December 2018 were included. The presence of residual p-VCRs was confirmed intraoperatively using triamcinolone acetonide (TA). Patients with p-VCRs were divided into two groups: Group A comprised of patients who underwent PPV without p-VCR removal, while Group B included patients who underwent PPV with p-VCR removal.

RESULTS

Four hundred-thirteen eyes with evidence of p-VCR were analyzed. Two-hundred-twenty-three eyes underwent PPV without VCR removal (Group A), while 190 eyes underwent PPV with p-VCR removal (Group B). Primary anatomical success was 91.5% in the Group A and 95.4% in the group B. Retinal re-detachment due to PVR occurred in 17 (7.6%) eyes in Group A and in four (2.1%) eyes in Group B within the first 3 months (p  =  0.01). Among group A, in 11 eyes, there was a diffuse posterior PVR grade C, while six eyes were focal PVR grade C. In Group B, we observed four retinal re-detachment due to focal PVR grade C.

CONCLUSION

The presence of p-VCRs seems to be associated with a higher incidence of PVR development and might also result in more complex RD recurrence, this suggests the need for more aggressive VCRs removal during the first surgery.

Comparison of Posterior Hyaloid Assessment Using Preoperative Optical Coherence Tomography and Intraoperative Triamcinolone Acetonide Staining During Vitrectomy

Purpose

To compare the specificity of diagnosing posterior vitreous detachment (PVD) using preoperative optical coherence tomography (OCT) versus intraoperative triamcinolone acetonide (TA) staining in patients undergoing vitrectomy.

Patients and Methods

This retrospective cohort study included patients undergoing pars plana vitrectomy for diverse retinal pathologies. Intraoperatively, surgeons evaluated the posterior hyaloid status with TA staining and compared it with preoperative OCT findings.

Results

One hundred six patients underwent intraoperative assessments of posterior hyaloid status, with 72% (76/106) of the eyes showing positive staining. Sixty-two patients had also undergone preoperative OCT. Of the patients diagnosed with PVD on preoperative OCT, 50% (15/30) showed positive TA staining intraoperatively. The sensitivity of preoperative OCT assessment was 83.3%, and its specificity was 65.9%.

Conclusion

Preoperative OCT imaging is associated with lower sensitivity and specificity for diagnosing PVD when compared to intraoperative TA staining.

Posterior Vitreous Detachment in Normal Healthy Subjects Younger Than Age Twenty

Purpose

To describe the initiation of posterior vitreous detachment (PVD) in the eyes of normal individuals, under 20 years of age, using wide-angle optical coherence tomography (OCT).

Methods

This is an observational cross-sectional study. Montaged images of horizontal and vertical OCT scans were obtained in 63 healthy eyes of 35 consecutive subjects ranging in age from 4 to 17 years.

Results

Forty-five eyes (71.4%) had obvious PVD, defined as a contiguous line of posterior cortical vitreous separated from the surface of the retina. Eighteen eyes (28.6%) had no PVD. The mean age of the individuals without PVD was significantly younger than those with PVD (P = 0.008). The spatial distribution of PVD initiation was highest in the superior quadrants, with the nasal, inferior, septum papillomaculae, and temporal quadrants following in descending order of frequency (P < 0.001). PVD was observed to begin anterior to the premacular liquefied lacuna, where the vitreous gel directly adheres to the vitreoretinal interface. In the majority of subjects (80.6%), PVD was initiated anterior to the vascular arcades.

Conclusions

PVD can be observed by OCT to begin in the first and second decade of life. It begins in the mid-peripheral vitreous, most frequently in the superior quadrants anterior to the vascular arcades. In this study, all PVDs originated outside of the macular liquefied lacunae, where the vitreous gel adheres directly to the retina.

PREVALENCE OF VITREOUS CORTEX REMNANTS IN EYES WITH PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT UNDERGOING VITRECTOMY

BACKGROUND/PURPOSE

To evaluate the prevalence and extent of vitreous cortex remnants (VCR) on the surface of the retina in eyes with primary rhegmatogenous retinal detachment (RRD) and posterior vitreous detachment.

METHODS

Triamcinolone acetonide was injected in the vitreous cavity of 100 consecutive cases of acute primary RRD undergoing pars plana vitrectomy. A multivariate regression analysis was performed to determine any association between the presence and pattern of stained VCR on the surface of the retina and the following variables: age, diabetes, axial length, phakic status, extent of RRD, and macular status.

RESULTS

Vitreous cortex remnants were found in 42 eyes. These were focal in eight eyes and diffuse in 34 eyes. Age was the only strong and independent risk factor associated with the presence of VCR (P = 0.0019). Age (P < 0.0001), axial length (P = 0.0037), and phakia (P = 0.01) were independent risk factors associated with the diffuse pattern. Neither diabetes, extent of RRD, nor macular status were significant risk factors for the presence or extent of VCR.

CONCLUSION

Older patients with primary RRD and posterior vitreous detachment seem to be at a higher risk of having diffuse VCR. Further studies are needed to investigate the relevance of VCR in the pathogenesis, progression and treatment of RD.

PROGRESSION OF PARTIAL POSTERIOR VITREOUS DETACHMENT OVER TIME

PURPOSE

We investigated interindividual differences in the rate of change of posterior vitreous detachment (PVD) stage and vitreomacular adhesion area (VMAA). Crosssectional studies demonstrated increasing PVD stage and decreasing VMAA with age, but population-level means may mask interindividual variation in the rate of change.

METHODS

We retrospectively evaluated PVD stage and VMAA in asymptomatic eyes of subjects who underwent repeated optical coherence tomography screening for high-risk medication use or isolated retinal disease in the fellow eye. A Turnbull estimator modeled changes in the PVD stage, and linear mixed models evaluated VMAA change.

RESULTS

We evaluated 101 eyes of 101 subjects. Seventy-six eyes remained in the same stage. Twenty-three eyes progressed to a higher stage. Modeling of longitudinal data predicts that at age 30, time to convert to Stage 4 is 26 years; at age 40, it is 16 years; at age 50, it is 9 years; and at age 60, it is 8 years. In 37 eyes with Stage 1 partial PVD, VMAA decreased at a similar rate. The average population level decline in VMAA was 0.13 mm2/year.

CONCLUSION

Individuals vary in age at which they progress to complete PVD. In early partial PVD, VMAA decreases at a similar rate across individuals.

Müller cells and astrocytes in tractional macular disorders

Tractional deformations of the fovea mainly arise from an anomalous posterior vitreous detachment and contraction of epiretinal membranes, and also occur in eyes with cystoid macular edema or high myopia. Traction to the fovea may cause partial- and full-thickness macular defects. Partial-thickness defects are foveal pseudocysts, macular pseudoholes, and tractional, degenerative, and outer lamellar holes. The morphology of the foveal defects can be partly explained by the shape of Müller cells and the location of tissue layer interfaces of low mechanical stability. Because Müller cells and astrocytes provide the structural scaffold of the fovea, they are active players in mediating tractional alterations of the fovea, in protecting the fovea from such alterations, and in the regeneration of the foveal structure. Tractional and degenerative lamellar holes are characterized by a disruption of the Müller cell cone in the foveola. After detachment or disruption of the cone, Müller cells of the foveal walls support the structural stability of the foveal center. After tractional elevation of the inner layers of the foveal walls, possibly resulting in foveoschisis, Müller cells transmit tractional forces from the inner to the outer retina leading to central photoreceptor layer defects and a detachment of the neuroretina from the retinal pigment epithelium. This mechanism plays a role in the widening of outer lameller and full-thickness macular holes, and contributes to visual impairment in eyes with macular disorders caused by conractile epiretinal membranes. Müller cells of the foveal walls may seal holes in the outer fovea and mediate the regeneration of the fovea after closure of full-thickness holes. The latter is mediated by the formation of temporary glial scars whereas persistent glial scars impede regular foveal regeneration. Further research is required to improve our understanding of the roles of glial cells in the pathogenesis and healing of tractional macular disorders.

NOVEL THREE TYPES OF NEOVASCULARIZATION ELSEWHERE DETERMINE THE DIFFERENTIAL CLINICAL FEATURES OF PROLIFERATIVE DIABETIC RETINOPATHY

PURPOSE

To explore the pathological features and clinical significance of three types of neovascularization elsewhere (NVE) in proliferative diabetic retinopathy.

METHODS

Neovascularization elsewhere was classified based on the origins and morphologic features using fluorescein angiography and angiographic and structural optical coherence tomography. The topographical distribution, vitreoretinal interface, and responsiveness to panretinal photocoagulation were compared among three types of NVE.

RESULTS

One hundred and twenty-seven NVEs were classified into three types. Type 1 NVE was concentrated along or adjacent to vascular arcades; Type 2 was distributed more peripherally than were Types 1 and 3 NVE. The arch bridge-like vitreoretinal interface accounted for 79% of Type 1 NVE. The flat and flat-forward vitreoretinal interface accounted for 95% and 100% in Type 2 and Type 3 NVE, respectively. At 3 months after panretinal photocoagulation, the regression rates for Types 1, 2, and 3 NVE were 82%, 100%, and 80%, respectively. Type 2 NVE showed best regression rate after panretinal photocoagulation (both P < 0.01).

CONCLUSION

Three types of NVE determine the distinctly topographical distributions, vitreoretinal interface features, and differential responsiveness to panretinal photocoagulation treatment. This new concept may have important clinical implications in assessing the treatment and prognosis of proliferative diabetic retinopathy.

Sensitivity of spectral domain optical coherence tomography in the diagnosis of posterior vitreous detachment in vitreomacular interface disorders: A prospective cohort study

PURPOSE

To evaluate the sensitivity of Spectral Domain Optical Coherence Tomography (SD-OCT) regarding the diagnosis of posterior vitreous detachment (PVD) in vitreomacular interface disorders (VID).

METHODS

A total of 48 eyes of 48 patients were included in this prospective cohort study. PVD in eyes with VID was investigated. We determined the status of posterior vitreous cortex using slit lamp (SL) biomicroscopy and SD-OCT preoperatively, during vitrectomy and on the intraoperative video recording. Sensitivity and specificity of the examining methods were analysed. Four masked independent examiners participated in this study.

RESULTS

PVD was diagnosed in 16 eyes (33.3%) on SD-OCT, 20 eyes (41.7%) on SL examination and 28 eyes (58.3%) during vitrectomy. Sensitivity and specificity for diagnosis of PVD was 37.5% and 31.3% using SD-OCT, 90% and 64.3% on the SL examination, 92.9% and 90% on the video recording respectively, compared to the intraoperative PVD diagnosis.

CONCLUSION

SD-OCT shows a relatively low detection sensitivity of PVD in VID. Thorough OCT investigation is necessary to establish an appropriate diagnosis of PVD and treatment in VID.

Foveal configurations with disappearance of the foveal pit in eyes with macular pucker: Presumed role of Müller cells in the formation of foveal herniation

Many eyes with macular pucker are characterized by a centripetal displacement of the inner foveal layers which may result in a disappearance of the foveal pit. In this retrospective case series of 90 eyes with macular pucker of 90 patients, we describe using spectral-domain optical coherence tomography different foveal configurations with ectopic inner foveal layers, document the relationship between posterior vitreous detachment (PVD) and idiopathic epiretinal membrane (ERM) formation and spontaneous and postoperative morphological alterations of the fovea, and propose an active role of Müller cells in the development of foveal herniation. We found that ERM were formed during or after partial perifoveal PVD, or after foveal deformations caused by tissue edema. The ERM-mediated centripetal displacement of the inner foveal layers and in various eyes anterior hyaloidal traction caused a disappearance of the foveal pit and an anterior stretching of the foveola with a thickening of the central outer nuclear layer (ONL). After the edges of the thickened inner layers of the foveal walls moved together, continuous centripetal displacement of the inner foveal layers generated a bulge of the fovea towards the vitreous (foveal herniation). Macular pseudoholes with a herniation of the inner foveal layers show that the outer layer of the protruding foveal walls is the outer plexiform layer (OPL). If the ERM covered the foveal walls and parafova, but not the foveola, the inner layers of the foveal walls were not fully centripetally displaced and the foveal pit was present. The visual acuity of eyes with ectopic inner foveal layers was inversely correlated with the thickness of the foveal center. Spontaneous morphological alterations after disappearance of the foveal pit may include the development of cystoid macular edema or additional thickening of the foveal tissue and foveal herniation. The foveal configuration with ectopic inner layers of the foveal walls and a thick central ONL persisted over longer postoperative time periods. The data show that the centripetal displacement of the inner foveal layers in eyes with macular pucker, which results in a disappearance of the foveal pit, may also generate foveal herniation which is suggested to be caused by contraction of Müller cell processes in the OPL. The centripetal displacement of the inner foveal layers and the formation of foveal herniation are suggested to reverse the foveal pit formation during development.

Volumetric Optical Imaging and Quantitative Analysis of Age-Related Changes in Anterior Human Vitreous

Purpose

The purpose of this study was to characterize age-related changes in anterior human vitreous with 3-D swept source optical coherence tomography (SS-OCT) and evaluate associations with axial length (AL) and contrast sensitivity function (CSF).

Methods

There were 49 phakic eyes in 49 patients (40.0 ± 19.3 years) had 3-D volumetric scanning of the lens and retrolental vitreous with SS-OCT at 1050 nm. OCT-derived indices of vitreous optical density (VOD), vitreous opacification ratio (VOR), and lens optical density (LOD) were correlated with AL and double-pass assessment of retinal point spread function (Objective Scatter Index [OSI]). CSF was measured using an adaptive-optics visual simulator (area under log-log contrast sensitivity function [AULCSF]).

Results

Vitreous SS-OCT detected gel vitreous, liquefied lacunae, Berger's space, retrolental laminae, and fibrous opacifications. VOD, VOR, and LOD showed high reproducibility (intraclass correlation coefficients 0.968, 0.975, and 0.998, respectively). VOD was highly correlated with VOR (Pearson's R = 0.96, P < 0.000001). VOD, VOR, and LOD correlated with age (R = 0.48, 0.58, and 0.85, P < 0.001 for each). VOR and LOD correlated with OSI (R = 0.36, P = 0.0094, and R = 0.36, P = 0.0096, respectively). VOR correlated negatively with AULCSF (R = −0.53, P < 0.00009), which was related to OSI. Myopic eyes had higher OSI than nonmyopic eyes (P = 0.0121), consistent with correlation between OSI and AL (R = 0.37, P = 0.0091). Multivariable regression confirmed these findings.

Conclusions

SS-OCT visualized microstructural features of anterior human vitreous, where opacification is associated with increased light scattering and CSF degradation. SS-OCT enables high-resolution optical evaluation of vitreous opacities.

[Retinal imaging of vitreomacular traction diseases]

Advances in imaging techniques of the retina have substantially enhanced our current understanding of the pathogenesis, morphology and prognosis of vitreomacular retinal diseases. Optical coherence tomography-based criteria and classification systems were recently proposed for uniform diagnoses and treatment recommendations for patients with vitreomacular traction, epiretinal gliosis and the various forms of macular holes. This article provides an overview of the different retinal imaging modalities as well as the currently recommended classification for vitreomacular traction pathologies.

Expression of Lymphatic Markers in the Berger's Space and Bursa Premacularis

We previously reported that the bursa premacularis (BPM), a peculiar vitreous structure located above the macula, contains numerous cells expressing markers of lymphatic endothelial cells, such as podoplanin and LYVE-1. Herein, we examined the expression of lymphatic markers in the Berger’s space (BS), BPM, and vitreous core (VC). BS, BPM, and VC specimens were selectively collected in macular hole and epiretinal membrane patients during vitrectomy and were then immunostained with antibodies for podoplanin, LYVE-1, and fibrillin-1 and -2. By visualization using triamcinolone acetonide, the BS was recognized as a sac-like structure with a septum located behind the lens as well as BPM. Those tissues adhered to the lens or retina in a circular manner by means of a ligament-like structure. Immunostaining showed intense expression of podoplanin and LYVE-1 in the BS. Both BS and BPM stained strongly positive for fibrillin-1 and -2. The VC was faintly stained with antibodies for those lymph-node markers. Our findings indicate that both BS and BPM possibly belong to the lymphatic system, such as lymph nodes, draining excess fluid and waste products into lymphatic vessels in the dura mater of the optic nerve and the ciliary body, respectively, via intravitreal canals.

Swept Source Optical Coherence Tomography Assessment of Bursa Premacularis in Healthy Eyes

Purpose

To describe the reliability and the limits of bursa premacularis (BPM) evaluation using a swept source optical coherence tomography (SS-OCT) device with enface and 16 mm-high definition (HD) longitudinal scans.

Methods

60 eyes of 60 subjects were enrolled and imaged with SS-OCT system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). BPM area was measured using enface scans imported to ImageJ. HD horizontal and vertical longitudinal scans centered at the fovea were used to detect width (W) and central thickness (CT) of BPM at baseline (T₀) and after 30 minutes (T₃₀) performed by two different observers. An enhanced vitreous visualization software provided by the manufacturer of the device was used to highlight vitreous structures.

Results

BPM was identifiable in 100% of eyes using both horizontal and vertical longitudinal scans. On horizontal scan, BPM was not entirely measurable in 21.7% and in 18.3% of cases at T₀ and T₃₀, respectively. On vertical scan, BPM was not entirely measurable in 75.0% and in 81.7% at T₀ and T₃₀, respectively. No statistically significant differences were found between the two different time measurements with an intraclass correlation coefficient above 70%. Median BPM area was 26.9 (Q₁-Q₃: 19.5-40.5) mm². In en face imaging, the most frequent BPM shape was the boat one.

Conclusion

SS-OCT is a reliable tool for a detailed quantification and mapping of BPM, and it is able to add useful details about the morphological BPM features in youth population. However, the enhanced visualization of the vitreous structures is still a challenge, also with the most forefront devices.

Recurrent Vitreomacular Traction in a Patient Treated with Ocriplasmin: A Case Report

INTRODUCTION

To describe a case of recurrent vitreomacular traction and macular edema that appeared both before and after the intravitreal injection of ocriplasmin.

CASE REPORT

An 82-year-old monocular man presented with metamorphopsia and reduced vision of 1-week duration. The patient's general medical history was unremarkable. His ophthalmic history was significant for severe ocular trauma in the right eye in childhood that caused phthisis. The left eye had undergone uncomplicated phacoemulsification 3 months earlier and the 1-month postoperative best corrected visual acuity (BCVA) was logarithmic mean angle of resolution (logMAR) 0.0. There was no history of other ocular conditions. At presentation, BCVA was logMAR 0.2 and optical coherence tomography (OCT) revealed the presence of cystoid macular edema caused by vitreomacular traction (VMT). The patient was scheduled for intravitreal ocriplasmin injection. Prior to treatment, the vision improved spontaneously to logMAR 0.1, and no VMT could be detected with spectral domain (SD)-OCT. The ocriplasmin injection was deferred but 3 weeks later the patient presented again with metamorphopsia, while VMT was again evident on SD-OCT. Ocriplasmin was injected and 1 month later the BCVA reached logMAR 0.1 without VMT. However, at 2 months post injection the VMT reappeared and a conservative approach with observation and topical nepafenac administration was decided. At the 3-month post-injection visit there was no VMT. More than 3 years after the ocriplasmin injection there is still no evidence of VMT, the patient is free of metamorphopsia, and his BCVA is logMAR 0.0.

CONCLUSION

Separation of consecutive layers of the vitreous cortex (vitreoschisis) may account for recurrent VMT.

Vitrectomy for the removal of idiopathic epiretinal membrane with or without internal limiting membrane peeling: a meta-analysis

Purpose:

The aim of this study is to analyze the effect of internal limiting membrane peeling in removal of idiopathic epiretinal membranes through meta-analysis.

Methods:

We searched PubMed for studies published until 30 April 2018. Inclusion criteria included cases of idiopathic epiretinal membranes, treated with vitrectomy with or without internal limiting membrane peeling. Exclusion criteria consisted of coexisting retinal pathologies and use of indocyanine green to stain the internal limiting membrane. Sixteen studies were included in our meta-analysis. We compared the results of surgical removal of epiretinal membrane, with or without internal limiting membrane peeling, in terms of best-corrected visual acuity and anatomical restoration of the macula (central foveal thickness). Studies or subgroups of patients who had indocyanine green used as an internal limiting membrane stain were excluded from the study, due to evidence of its toxicity to the retina.

Results:

Regarding best-corrected visual acuity levels, the overall mean difference was –0.29 (95% confidence interval: –0.319 to –0.261), while for patients with internal limiting membrane peeling was –0.289 (95% confidence interval: –0.334 to –0.244) and for patients without internal limiting membrane peeling was –0.282 (95% confidence interval: –0.34 to –0.225). Regarding central foveal thickness levels, the overall mean difference was –117.22 (95% confidence interval: –136.70 to –97.74), while for patients with internal limiting membrane peeling was –121.08 (95% confidence interval: –151.12 to –91.03) and for patients without internal limiting membrane peeling was –105.34 (95% confidence interval: –119.47 to –96.21).

Conclusion:

Vitrectomy for the removal of epiretinal membrane combined with internal limiting membrane peeling is an effective method for the treatment of patients with idiopathic epiretinal membrane.

The Effect of Internal Limiting Membrane Cleaning on Epiretinal Membrane Formation after Vitrectomy for Proliferative Diabetic Retinopathy

PURPOSE

We hypothesised that cleaning the internal limiting membrane (ILM) with a flexible nitinol loop following diabetic vitrectomy without peeling may reduce the common occurrence of postoperative epiretinal membrane (ERM) formation.

METHODS

Consecutive patients undergoing vitrectomy for proliferative diabetic retinopathy by one surgeon from 2015 to 2019 were studied and divided into 2 cohorts: the control group underwent standard surgery, and the ILM clean group underwent additional cleaning of the macular retina using a flexible nitinol loop after vitrectomy. Masked comparison of ERM on optical coherence tomography was performed at 3 months, and visual acuity (VA) was measured until 12 months postoperatively.

RESULTS

Baseline demographics, clinical features, and protein levels were similar between cohorts. The ILM clean group (n = 56) had fewer clinically significant ERM than the control group (n = 50; 4 vs. 20%; p = 0.01), and a significantly lower proportion of the ILM clean group required revision surgery (2 vs. 14%; p = 0.02). VA in the ILM clean group was significantly better than in the control group at 3 months (0.35 vs. 0.50 logMAR; p = 0.02) but not at 12 months (0.34 vs. 0.43 logMAR; p = 0.17).

CONCLUSION

ILM cleaning with a flexible nitinol loop following diabetic vitrectomy resulted in significant reduction in ERM formation and reduced necessity for revision surgery. There was significant improvement in VA at 3 months but not over a longer follow-up.

Standard 6-mm Compared with Widefield 16.5-mm OCT for Staging of Posterior Vitreous Detachment

PURPOSE

To assess whether 6-mm OCT scans, which image the macula, can distinguish complete from partial posterior vitreous detachment (PVD) in comparison with 16.5-mm OCT scans, which image the macula, optic nerve, and mid periphery.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

We compared 6-mm and 16.5-mm scans in 157 eyes of 157 retina clinic patients (mean age, 50 years; range, 10-64 years) with diabetic retinopathy (36%), no retinal disease (19%), and various retinal conditions (45%). We also analyzed 16.5-mm scans in 35 healthy eyes (asymptomatic fellow eyes of patients with unilateral retinal conditions; mean age, 46 years; range, 9-63 years).

METHODS

Each participant underwent Heidelberg Spectralis imaging with the standard lens (6-mm scan) and/or the 55° lens (16.5-mm scan). On 6-mm scans, we classified eyes as stage 3 partial PVD when the posterior vitreous cortex was visualized without visible attachment. On 16.5-mm scans, we classified eyes as stage 3 when the vitreous was attached at the optic nerve and separated from the macula. On both scan types, we classified eyes as stage 4 when neither the premacular bursa nor the posterior vitreous cortex were visualized. We assessed the accuracy of this system for detecting complete PVD on 6-mm scans by calculating test characteristics using 16.5-mm scans as a reference standard.

MAIN OUTCOME MEASURE

Posterior vitreous detachment stage (0-4).

RESULTS

Posterior vitreous detachment stage was identical in 6-mm and 16.5-mm scans in 88% of eyes. Compared with 16.5-mm scans, 6-mm scans detected complete PVD (vs. earlier stages 0-3) with 91% sensitivity and 99% specificity. Seven eyes were classified as no PVD on 6-mm scans and were classified as partial PVD on 16.5-mm scans because vitreoretinal separation was localized to the mid periphery. All 16.5-mm scans showed some degree of PVD, including scans from 9 participants between 9 and 20 years of age.

CONCLUSIONS

Six-millimeter scans distinguished complete from partial PVD with good sensitivity and specificity but missed the earliest stages of PVD, which occur in the mid periphery. Posterior vitreous detachment may begin as early as the second decade of life.

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.

Vitreous Antioxidants, Degeneration, and Vitreo-Retinopathy: Exploring the Links

The transparent vitreous body, which occupies about 80% of the eye’s volume, is laden with numerous enzymatic and non-enzymatic antioxidants that could protect the eye from oxidative stress and disease. Aging is associated with degeneration of vitreous structure as well as a reduction in its antioxidant capacity. A growing body of evidence suggests these age-related changes may be the precursor of numerous oxidative stress-induced vitreo-retinopathies, including vision degrading myodesopsia, the clinically significant entoptic phenomena that can result from advanced vitreous degeneration. Adequate intravitreal antioxidant levels may be protective against vitreous degeneration, possibly preventing and even improving vision degrading myodesopsia as well as mitigating various other vitreo-retinopathies. The present article is, therefore, a review of the different antioxidant molecules within vitreous and the inter-relationships between vitreous antioxidant capacity and degeneration.

Accuracy of Spectral-Domain OCT of the Macula for Detection of Complete Posterior Vitreous Detachment

PURPOSE

To assess the accuracy of macular spectral-domain OCT in detecting complete posterior vitreous detachment (PVD).

DESIGN

Evaluation of diagnostic test or technology using a retrospective comparative study.

PARTICIPANTS

One hundred seventy-five eyes in 175 patients (111 women and 64 men; mean age, 65 years) with preoperative OCT within 90 days of vitrectomy.

METHODS

Posterior vitreous detachment status on preoperative macular OCT was compared with PVD determination during vitrectomy. Attached vitreous was identified on OCT by visualizing the posterior vitreous cortex or premacular bursa. Complete PVD was identified by the absence of these findings and considered a positive outcome for the purpose of analysis.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value, and negative predictive value of macular OCT for detection of complete PVD compared with findings at surgery.

RESULTS

Of the 38 eyes graded as showing complete PVD on OCT, 20 eyes were found to have pre-existing PVD at the time of surgery (true-positive results), and 18 eyes were found to have attached vitreous at the time of surgery (false-positive results). Of the 137 eyes graded as showing attached vitreous on OCT, 129 eyes had attached vitreous at the time of surgery (true-negative results), and 8 eyes had pre-existing PVD at the time of surgery (false-negative results). The sensitivity of OCT for detecting complete PVD was 71% and the specificity was 88%. In the study population, the positive predictive value of an OCT scan showing complete PVD was 53%, whereas the negative predictive value of an OCT scan showing attached vitreous was 94%.

CONCLUSIONS

If the premacular bursa or posterior vitreous cortex are visualized on macular OCT, an accurate determination of attached vitreous can be made. The diagnosis of complete PVD by macular OCT is less accurate and requires ultrasound.

Complete Posterior Vitreous Detachment Reduces the Need for Treatment of Diabetic Macular Edema

BACKGROUND AND OBJECTIVE

To evaluate the vitreomacular interface and its relation to treatment burden for diabetic macular edema (DME) in patients without overt vitreomacular traction (VMT).

PATIENTS AND METHODS

A retrospective cohort study of 494 eyes from 274 patients who had macular spectral-domain optical coherence tomography (SD-OCT) and did not have proliferative diabetic retinopathy, DME, or VMT at the initial visit. Posterior vitreous detachment (PVD) was categorized at the initial visit into five stages (0-4) using SD-OCT parameters alone.

RESULTS

Two of 34 eyes (6.9%) presenting with a complete PVD required DME treatment during follow-up, whereas 144 of 460 eyes (31.3%) without a complete PVD at baseline required treatment (P = .001, Chi-squared). After adjusting for age, ethnicity, gender, and HbA1c, complete PVD at baseline was associated with a significant reduction in risk of DME therapy (hazard ratio: 0.18; 95% confidence interval, 0.05-0.73; P = .02).

CONCLUSION

Complete PVD is independently associated with a reduced need for DME treatment. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e266-e273.].

Ultra-Widefield Optical Coherence Tomographic Imaging of Posterior Vitreous in Eyes With High Myopia

PURPOSE

To investigate the morphological changes of posterior vitreous in highly myopic (HM) eyes of patients 50 years of age and older.

DESIGN

Retrospective, observational case series.

METHODS

Ultra-widefield swept-source OCT (UWF-OCT) examinations were performed on 768 eyes of 448 HM patients (50-89 years of age) and 54 eyes of 52 non-HM subjects with scan widths of 23 mm and depths of 5 mm. HM was defined as an axial length longer than 26.5 mm. The area and morphology of the posterior vitreous detachments (PVDs) and adhesions onto retinal vessels were examined for in 167 HM eyes and in 11 non-HM eyes in which the vitreal images were clear.

RESULTS

Paramacular PVD, perifoveal PVD, peripapillary PVD, and complete PVD were found in 9%, 47%, 41%, and 3% of the 167 HM eyes, respectively, and in 37%, 45%, 18%, and 0% of the 11 non-HM eyes, respectively. In eyes with vitreofoveal adhesions, the PVDs were more commonly asymmetrical relative to the fovea in the HM eyes than in the non-HM eyes (94% vs. 44%, respectively; P < .001). The area of the PVD corresponded with the area where the sclera protruded posteriorly. A thickened vitreous was observed to adhere to the retinal vessels at multiple points and was accompanied by paravascular abnormalities including lamellar holes in HM eyes. A total of 54 of the 167 HM eyes had macular retinoschisis, and the eyes commonly had vitreal traction on retinal vessels compared to HM eyes without macular retinoschisis (P = .031).

CONCLUSIONS

PVD progressed asymmetrically and were associated with scleral curvature in HM eyes. Vitreous traction spanning a wide distance may lead to myopic traction maculopathy.

Vitreous Wiping, a new technique for removal of vitreous cortex remnants during vitrectomy

PURPOSE

Unremoved vitreoschisis-induced vitreous cortex remnants (VCR) are associated with macular pathology. When present on the retinal periphery, they may play a role in proliferative vitreoretinopathy and retinal detachment after vitrectomy. Existing instruments for their removal involve substantial risk of iatrogenic retinal damage. Purpose of this study was to evaluate the use of a new technique, Vitreous Wiping, for removal of VCR during vitrectomy.

METHODS

Proof-of-concept case series of six eyes (six patients) treated with vitrectomy for various pathologies (macula-on and macula-off retinal detachment, macular hole, macular pucker and vitreous floaters). Vitreous cortex remnants on the surface of the retina were visualized with triamcinolone and removed by Vitreous Wiping with a rectangular piece of polyvinyl alcohol (PVA) held with intra-ocular forceps. Visual acuity and clinical course were assessed during a follow-up of 6 months. All eyes underwent postoperative macular optical coherence tomography. Eyes without preoperative macular pathology, underwent retinal sensitivity testing and eyes without paracentral pathology underwent visual field analysis.

RESULTS

Vitreous cortex remnants could be removed completely in all eyes. There were no intra- or postoperative complications. We observed that PVA is soft like a sponge and vitreous sticks to it, making Vitreous Wiping easier and safer, compared to alternative instruments. Visual acuity improved in all eyes. Microperimetry and visual field analysis revealed no abnormalities related to Vitreous Wiping.

CONCLUSION

Vitreoschisis-induced VCR can be removed effectively and safely from the retinal surface by Vitreous Wiping. Larger studies are needed to confirm this promising finding and its potential impact.

Effects of Collagenase Type II on Vitreous Humor—An In Situ Rheological Study

The purpose of this study is to quantify the impact of enzyme activity on the vitreous humor structure over time to understand the mechanical characteristics of the vitreous humor gel. Changes in the mechanical behavior of the vitreous occur due to many reasons including aging, which may lead to many vitreoretinal diseases. The degeneration process of the vitreous has been studied; however, in situ experimental procedures to validate the existing hypotheses are limited. We examined thirty-eight porcine eyes using in situ rheological creep tests to measure the mechanical properties of the vitreous humor of the eyes prior to, 1 h and 24 h after the intravitreal injection. Eyes in one group were injected with collagenase type II solution and eyes in the control group were injected with phosphate buffered saline solution (PBS) with calcium and magnesium chloride. Prior to the injection, viscosity and creep compliance intercept values between both groups were not statistically different. At 1 h and 24 h after the injection, vitreous properties in the eyes from the first group showed a statistically significant increase in the J intercept values (representing the inverse of elasticity) compared to the control group. In addition, 1 h and 24 h after the injection, vitreous viscosity was lower in the eyes from the first group than in the eyes from the control group. These findings are a foundation for future studies on the effectiveness of intravitreal drugs that modify the mechanical properties of the vitreous humor.