Partial Posterior Vitreous Detachment Research Articles

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

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. 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. 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. 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. 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.

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

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). 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. 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%). 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.

Vitreomacular interface abnormalities in the Ghanaian African

Background/ObjectiveDescribe vitreomacular interface abnormalities (VMIA) using spectral-domain optical coherence tomography (SD-OCT), and correlations with age-related macular degeneration (AMD) grade in Ghanaian Africans.Subjects/MethodsProspective, cross-sectional study of adults aged ≥50 years recruited in Ghana AMD Study. Participant demographics, medical histories, ophthalmic examination, digital colour fundus photography (CFP) were obtained. High-resolution five-line raster OCT, Macular Cube 512 × 128 scans, and additional line scans in areas of clinical abnormality, were acquired. SD-OCT VMI features classified by International Vitreomacular Traction Study Group system and relationships to AMD grade were evaluated. Outcomes: VMIA prevalence, posterior vitreous detachment (PVD), vitreomacular adhesions (VMA), vitreomacular traction (VMT), epiretinal membranes (ERM), correlations with AMD grade.ResultsThe full Ghana AMD cohort included 718 participants; 624 participants (1248 eyes) aged ≥50 years (range = 50–101, mean = 68.8), 68.9% female were included in this analysis. CFP with OCT scans were available for 776 eyes (397 participants); 707 (91.1%) had gradable CFP and OCT scans for both AMD and VMI grading forming the dataset for this report. PVD was absent in 504 (71.3%); partial and complete PVD occurred in 16.7% and 12.0% respectively. PVD did not increase with age (p = 0.720). VMIA without traction and macular holes were observed in 12.2% of eyes; 87.8% had no abnormalities. VMIA was not significantly correlated with AMD grade (p = 0.819).ConclusionsThis provides the first assessment of VMIA in Ghanaian Africans. VMIA are common in Africans; PVD may be less common than in Caucasians. There was no significant association of AMD grade with VMIA.

Bioelectrical impedance analysis in patients with posterior vitreous detachment.

The purpose of the study is to assess body hydration in patients with posterior vitreous detachment (PVD) by bioelectrical impedance analysis (BIA). PVD, one of the most common eye diseases, is associated in both research and the collective image with reduced daily water intake, but this finding is not supported by strong evidence in the literature. Based on Spectral Domain Optical Coherence Tomography (SD-OCT) evaluation, different PVD stages are identified: absent posterior vitreous detachment, partial posterior vitreous detachment (P-PVD), or complete posterior vitreous detachment (C-PVD). BIA is a simple, non-invasive bedside method used to assess body composition. Patients underwent BIA and completed a floaters symptoms. 30 patients were enrolled and divided into two groups according to the degree of vitreous detachment, in P-PVD (n=12) and C-PVD (n=18). Patients underwent BIA and completed a floaters symptoms questionnaire. BIA measured the Resistance (R), Reactance (Xc), Phase Angle (PhA), Total Body Water (TBW), Extracellular Water (ECW), Fat Mass (FM), Fat-Free Mass (FFM), and Body Cell Mass Index (BCMI). Finally, patients received a test to assess adherence to the Mediterranean diet (Mediterranean Diet Test Score, MDTS) with the addition of daily water intake. Relevant data were obtained from the BIA evaluation: the values of R and Xc were lower in the P-PVD group than C-PVD group (respectively 417.08±58.12 Ω vs. 476.94±51.29 Ω p=0.006 and 41.33±8.23 Ω vs. 50.61±7.98 Ω p=0.004). Instead, patients in the P-PVD group reported higher values of TBW and ECW than C-PVD group (respectively 44.13±7.57 L vs. 37.96±6.27 L p=0.021 and 21.03±4.06 L vs. 17.24±2.63 L p=0.004). In the present study, we reported a significant correlation between vitreous pathology and anthropometric and BIA measurements.

RECURRENT FLOATERS AFTER LIMITED VITRECTOMY FOR VISION DEGRADING MYODESOPSIA.

Limited vitrectomy improves vision degrading myodesopsia, but the incidence of recurrent floaters postoperatively is not known. We studied patients with recurrent central floaters using ultrasonography and contrast sensitivity (CS) testing to characterize this subgroup and identify the clinical profile of patients at risk of recurrent floaters. A total of 286 eyes (203 patients, 60.6 ± 12.9 years) undergoing limited vitrectomy for vision degrading myodesopsia were studied retrospectively. Sutureless 25G vitrectomy was performed without intentional surgical posterior vitreous detachment (PVD) induction. CS (Freiburg Acuity Contrast test: Weber index, %W) and vitreous echodensity (quantitative ultrasonography) were assessed prospectively. No eyes (0/179) with preoperative PVD experienced new floaters. Recurrent central floaters occurred in 14/99 eyes (14.1%) without complete preoperative PVD (mean follow-up = 39 months vs. 31 months in 85 eyes without recurrent floaters). Ultrasonography identified new-onset PVD in all 14 (100%) recurrent cases. Young (younger than 52 years; 71.4%), myopic (≥-3D; 85.7%), phakic (100%) men (92.9%) predominated. Reoperation was elected by 11 patients, who had partial PVD preoperatively in 5/11 (45.5%). At study entry, CS was degraded (3.55 ± 1.79 %W) but improved postoperatively by 45.6% (1.93 ± 0.86 %W, P = 0.033), while vitreous echodensity reduced by 86.6% ( P = 0.016). New-onset PVD postoperatively degraded CS anew, by 49.4% (3.28 ± 0.96 %W; P = 0.009) in patients electing reoperation. Repeat vitrectomy normalized CS to 2.00 ± 0.74%W ( P = 0.018). Recurrent floaters after limited vitrectomy for vision degrading myodesopsia are caused by new-onset PVD, with younger age, male sex, myopia, and phakic status as risk factors. Inducing surgical PVD at the primary operation should be considered in these select patients to mitigate recurrent floaters.

Tractional Retinal Detachment in Eyes with Vitreous Hemorrhage and Proliferative Diabetic Retinopathy and Posterior Vitreous Detachment in Fellow Eye.

To predict the presence of tractional retinal detachment (TRD) in eyes with dense vitreous hemorrhage (VH) and proliferative diabetic retinopathy (PDR) by evaluating the status of posterior vitreous detachment (PVD) in fellow eyes using optical coherence tomography (OCT). A total of 44 eyes from 22 patients who underwent vitrectomy due to dense VH with PDR were enrolled. Using OCT, the PVD status in the fellow eye was divided into two groups (incomplete and complete PVD). The incomplete PVD group included eyes without PVD and eyes with partial PVD. B-scan ultrasonography was performed on eyes with dense VH to evaluate the presence of TRD. Both OCT and B-scan images were reviewed by four ophthalmologists (two novices and two experienced), and the interobserver agreement was evaluated. There was a difference in the interobserver agreement regarding the presence of TRD in eyes with dense VH evaluated by B scan between novice and experienced ophthalmologists (novice, κ = 0.421 vs. experienced, κ = 0.814), although there was no difference between novice and experienced ophthalmologists in the interobserver agreement regarding the status of PVD in the fellow eye evaluated by OCT (novice, κ = 1.000 vs. experienced, κ = 1.000). All observed TRD during vitrectomy occurred in eyes with incomplete PVD in the fellow eye. Logistic regression analysis revealed a statistically significant relation between TRD and the age of the patient (odds ratio [OR], 0.874; p = 0.047), and between TRD and incomplete PVD in the fellow eye evaluated by OCT (OR, 13.904; p = 0.042). Evaluation of the PVD status in the fellow eye using OCT may be a useful predictor for detecting the presence of TRD in eyes with dense VH and PDR.

A novel recombinant human microplasminogen induced complete posterior vitreous detachment without morphological change of retina in juvenile rabbits

Vitreomacular traction syndrome results from persistent vitreoretinal adhesions in the setting of partial posterior vitreous detachment (PVD). Vitrectomy and reattachment of retina is an effective therapeutic approach. The adhesion between vitreous cortex and internal limiting membrane (ILM) of the retina is stronger in youth, which brings difficulties to induce PVD in vitrectomy. Several clinical investigations demonstrated that intravitreous injection of plasmin before vitrectomy could reduce the risk of detachment. In our study, a novel recombinant human microplasminogen (rhμPlg) was expressed by Pichia pastoris. Molecular docking showed that the binding of rhμPlg with tissue plasminogen activator (t-PA) was similar to plasminogen, suggesting rh μPlg could be activated by t-PA to generate microplasmin (μPlm). Moreover, rhμPlg had higher catalytic activity than plasminogen in amidolytic assays. Complete PVD was found at vitreous posterior pole of 125 μg rhμPlg-treated eyes without morphological change of retina in juvenile rabbits via intraocular injection. Our results demonstrate that rhμPlg has a potential value in the treatment of vitreoretinopathy.

Clinic study on macular epiretinal membrane in patients under the age of 40 years

BackgroundTo describe the risk factors and clinical characteristics of macular epiretinal membrane (MEM) disease in patients up to the age of 40 years and to evaluate the therapeutic effect of IVTA on MEM.MethodsClinical records were reviewed and the etiology of each case and the age distribution data were collected in this retrospective, cohort study. The clinical characteristics of MEM and the factors affecting VA were analyzed. Additionally, we contrasted the effects of MEM peeling with and without intravitreal triamcinolone acetonide on visual acuity (VA) and central foveal thickness (CFT).ResultsIn young patients, the incidence of partial posterior vitreous detachment (P-PVD) was considerably higher in IMEM than SMEM (P = 0.007). Furthermore, patients with stage 3 MEM had lower BCVA values than patients with stage 4 MEM (P < 0.001). Patients who live in urban had lower BCVA values than patients in rural (P < 0.001). Patients with IS/OS integrity had lower BCVA values than patients without IS/OS integrity (P < 0.001). The BCVA values in patients with IMEM were significantly lower than those of patients with SMEM (P < 0.001). BCVA was associated most commonly with etiology (P = 0.001), followed by region (P = 0.002). All patients had a decrease in logMAR Vas and CFT, but the combination of intraoperative IVTA resulted in a more significant decrease in logMAR Vas (P = 0.007) and CFT (P = 0.046).ConclusionIn young patients, the incidence of P-PVD was significantly higher in IMEM cases than in SMEM cases. The region, MEM stage, IS/OS integrity, and etiology influenced VA. Etiology was associated most commonly with BCVA. In individuals under 40, the combination of intraoperative IVTA resulted in a more significant decrease in logMAR Vas and CFT.

POSTERIOR VITREOUS DETACHMENT STATUS AS A PREDICTIVE FACTOR FOR OUTCOMES OF VITRECTOMY FOR DIABETIC VITREOUS HEMORRHAGE.

The purpose of this study was to evaluate the prognostic utility of the degree of vitreous attachment for predicting outcomes of vitrectomy for nonclearing vitreous hemorrhage associated with proliferative diabetic retinopathy. Medical records of patients who underwent primary vitrectomy for dense nonclearing vitreous hemorrhage secondary to proliferative diabetic retinopathy were examined retrospectively. Eyes were divided into four groups based on the intraoperatively assessed stage of posterior vitreous detachment (PVD), ranging from Stage 0/1 (complete or near-complete vitreoretinal adhesion) to Stage 4 (complete PVD). Overall, 136 eyes (117 patients) were included. In comparison with eyes with a partial or complete PVD (Stages 2-4), eyes with no PVD (Stage 0/1) had a higher incidence of postoperative hypotony (8%, P = 0.03) and traction retinal detachment (27%, P = 0.002), an increased rate of repeat vitrectomy (49%, P = 0.04), and poorer best-corrected visual acuity at 6 months and 1 year postoperatively (P = 0.04 and P = 0.01, respectively). Presence of a complete PVD at baseline was independently associated with improved postoperative vision at 6 months (P = 0.04). More extensive vitreoretinal adhesion is associated with higher rates of reoperation and poorer visual outcomes after vitrectomy for dense nonclearing vitreous hemorrhage associated with proliferative diabetic retinopathy. Preoperative determination of PVD status using B-scan ultrasonography may be useful for predicting anatomical and functional outcomes after vitrectomy in these patients.

Relationship Between Posterior Vitreous Detachment and Macular Dimensions in Myopic Eyes.

BackgroundPosterior vitreous detachment (PVD) can result in serious pathologic events at the vitreoretinal interface. This study aims to assess the relationship between PVD, macular thickness (MT), and the foveal avascular zone (FAZ) in myopic eyes.MethodsThis retrospective study evaluated 63 myopic subjects’ data who were examined between January 1 and June 30, 2019. The myopes were grouped on a severity scale, namely mild, moderate, high, and very high using their spherical equivalent (SE). The PVD classification was based on OCT images. The status of the PVD and MT were evaluated with the Macular Cube 200×200 images, the FAZ with an OCTA Angioplex, and the dimensions were calculated using a customized algorithm.ResultsThe study population (114 eyes) had a median (range) age was 26.00 (22.00–28.00) years and the females constituted 62.3% of the dataset. In this population, 10 eyes had no PVD in any quadrant, and 73 eyes had incomplete PVD in all four quadrants. The inferior quadrant had the maximum rate of PVD occurrences and the nasal quadrant had the least number of occurrences. High myopic eyes exhibited significantly increased low foveal volume (p = <0.01). The inferior part of the para- and perimacular area showed a significant thinning in very high myopic eyes (p = <0.050). The very high myopic eyes showed a significant alteration of FAZ’s circularity index (p = 0.002).ConclusionIn high and very high myopic eyes, an increasing trend of partial PVD is seen, most commonly in the inferior quadrant. A significant alteration in foveal volume and circularity index of the FAZ is seen in high and very high myopic eyes.

The Role of Internal Limiting Membrane as a Biomarker in the Evolution of Myopic Traction Maculopathy.

Purpose: To describe the longitudinal structural changes of myopic traction maculopathy (MTM) based on optical coherence tomography (OCT) and to detect biomarkers in the evolution of MTM.Methods: A retrospective study was conducted on patients with MTM as defined by OCT. A minimum follow-up of 6 months was necessary for study inclusion. The effects of comprehensive OCT-based structure on the evolution of MTM, the progression rates, and resolution rates of MTM were evaluated.Results: A total of 120 eyes (120 patients) were included with an average follow-up of 15.4 months. During the follow-up, MTM progressed in 32 eyes (26.67%). The most common pattern of progression observed was the increased extent of retinoschisis in 12 eyes. The multivariate analysis showed that the presence of MTM progression had a significant correlation with internal limiting membrane (ILM) detachment and retinoschisis involved the entire macula at baseline. Five eyes (4.17%) experienced MTM resolution, of which 2 eyes developed disruptions of detached ILM, two eyes developed disruptions of epiretinal membrane, and one eye developed partial posterior vitreous detachment. Eyes with foveal detachment showed the highest progression rate (41.67%) and highest resolution rate (16.67%) compared to the eyes with other foveal complications.Conclusion: ILM detachment is a risk factor for MTM progression and MTM resolution can occur after ILM disruption. These suggest that ILM may play an important role as a biomarker in the evolution of MTM.

Progression Patterns of Myopic Traction Maculopathy in the Fellow Eye After Pars Plana Vitrectomy of the Primary Eye.

PurposeThis retrospective study investigated the patterns and risk factors of progression of myopic traction maculopathy (MTM) of fellow eyes after pars plana vitrectomy (PPV) of primary eyes.MethodsThe study population comprised 153 patients with MTM in both myopic eyes who sequentially underwent PPV (2006–2021). Observation periods were from PPV of the primary eye (baseline) to PPV of the fellow (end). MTM was graded based on optical coherence tomography (OCT) images and the ATN (atrophy [A], traction [T], and neovascularization [N]) system. An increase in T grade was considered MTM progression.ResultsMTM progressed in 43.8% of fellow eyes during 34.57 ± 34.08 months. The progression of fellow eyes correlated with T grade of primary eyes (P < 0.001). Risk factors for the progression of MTM in fellow eyes were primary eyes in T4–T5, age at baseline <60 years, and fellow eyes with partial posterior vitreous detachment (PVD; P < 0.001, P = 0.042, and P = 0.002, respectively). Fellow eyes in T1/T2 at baseline progressed faster compared with those in T0 (P < 0.001); the annual rate of progression to T3–T5 of the T0 (T1–T2) groups was 9.98% (24.59%).ConclusionsRisk factors for the progression of MTM in fellow eyes included PPV when relatively young, primary eye at high T grade, and partial PVD of the fellow eye. Personalized follow-up for fellow eyes should be based on the severity of MTM of both eyes.

Evaluating posterior vitreous detachment by widefield 23-mm swept-source optical coherence tomography imaging in healthy subjects

Posterior vitreous detachment (PVD) is a separation between the posterior vitreous cortex and internal limiting membrane. Although PVD was historically considered an acute event, recent studies using spectral-domain optical coherence tomography (SD-OCT) revealed a gradual progression of PVD in healthy subjects. Although SD-OCT improved PVD studies, the narrow imaging angle and long examination time were problematic to allow wide angle capture. The Xephilio OCT-S1 (Canon), a swept-source OCT (SS-OCT) device, can obtain up to 23-mm of widefield B-scan images in a single acquisition. We used this widefield SS-OCT to quantitatively evaluate the PVD stage in 214 healthy subjects aged 4–89 years and determine whether PVD stages differ between the bilateral eyes of each patient. Age was significantly positively correlated with the overall PVD stage (ρ = 0.7520, P < 0.001). Interestingly, partial PVD occurred in children as young as 5 years, indicating that initial PVD onset may occur much earlier than previously reported. Furthermore, PVD stages of the bilateral eyes were highly consistent in 183 subjects (85.5%). Widefield 23-mm SS-OCT thus revealed that PVD started earlier than anticipated, and age was correlated with the symmetry of PVD stage. Widefield 23-mm SS-OCT may also be clinically useful for the evaluation of diseased eyes.

Natural course of myopic traction maculopathy and factors influencing progression and visual acuity

BackgroundTo describe the natural course of myopic traction maculopathy (MTM) and determine predictive factors for its progression and visual prognosis.MethodsThis retrospective observational study included 113 MTM patients (113 eyes). Best-corrected visual acuity (BCVA) measurements and optical coherence tomography findings were recorded.ResultsOver a mean follow-up of 38.2 ± 11.1 months, 49 of 113 eyes (43.4 %) progressed. The progression rate of outer schisis prominently located in the fovea or posterior staphyloma was significantly higher than that of outer schisis prominently located in paravascular areas (P = 0.0011). MTM with partial posterior vitreous detachment during the follow-up progressed more rapidly than MTM without (P = 0.0447). Patients with older age (> 65 years), without domed-shaped macula and with defects in the ellipsoid zone (EZ) had worse BCVA at the last visit (P = 0.0416, P = 0.0494and P = 0.0130). Multiple linear regression analysis showed that BCVA and defects in the EZ at baseline were significantly associated with the final BCVA (P < 0.0001 and P = < 0.0001, respectively).ConclusionsMTM has a high possibility for progression. Outer schisis located predominantly in the fovea or posterior staphyloma or with partial posterior vitreous detachment exhibits rapid progression. The integrity of the EZ is related to visual prognosis.

Posterior vitreous detachment and paravascular retinoschisis in highly myopic young patients detected by ultra-widefield OCT

The purpose of this study was to determine the relationship between a posterior vitreous detachment (PVD) and retinoschisis (RS) in 73 highly myopic (HM) young patients age 16.4 ± 6.9 years and 24 non-HM children age 8.4 ± 1.5 years. The presence of the paravascular retinal abnormalities was determined in the images obtained by a ultra-widefield OCT (UWF OCT) instrument with an image field of 23 × 20 mm. The results showed that a partial PVD was detected in 15 (21%) of the HM patients, and the number increased significantly with increasing age (P = 0.02). PVDs of any type were not found in the non-HM eyes. The number of microvascular folds also increased with age in the HM patients (P = 0.03). Medium-reflective columnar tissues were present between the detached vitreous and inner retinal surface in 4 (5%) eyes of the HM patients. Myopic RS was found in 3 (4%) HM patients in the paravascular area but not in the macular area. These results suggest that early partial PVD may play a role in pathological and proliferative vitreous changes of HM eyes. An intense vitreoretinal traction with bridging tissues may cause the various paravascular retinal abnormalities. In HM eyes, paravascular RS is already present at an early age which may progress to macular RS with aging.

Risk factors for onset or progression of epiretinal membrane after cataract surgery

While the precise diagnosis of early stage epiretinal membrane (ERM) at the time of cataract surgery and evaluation of risk factors for development or progression of ERM after cataract surgery is increasingly important, there is only limited information. In the present study, we evaluated the risk factors for onset or progression of ERM on spectral domain optical coherence tomography (SD-OCT) after cataract surgery. The univariate analysis showed that eyes with partial posterior vitreous detachment (PVD; p < 0.001), hyper-reflective foci (HF) on the inner retinal surface (p < 0.001), vitreoschisis (p = 0.014), and discrete margin of different retinal reflectivity (DMDRR; p = 0.007) on ultra-widefield fundus photography (UWF-FP) had significant risk for the onset or progression of ERM after cataract surgery. The multivariate analysis showed that partial PVD (HR, 3.743; 95% confidence interval [CI], 1.956–7.162; p < 0.001), HF (HR, 2.330; 95% CI, 1.281–4.239; p = 0.006), and DMDRR on UWF-FP (HR, 3.392; 95% CI, 1.522–7.558; p = 0.003) were the independent risk factors for the onset or progression of ERM after cataract surgery after adjustment for other confounding factors. Our study shows that the onset or progression of ERM after cataract surgery depends on an abnormal vitreoretinal interface (VRI) represented by partial PVD, HF on SD-OCT, and DMDRR on UWF-FP, not on age, axial length, or presence of ERM at the time of surgery. A meticulous funduscopic evaluation of the VRI would help to predict the ERM risk before cataract surgery.

PROGRESSION OF PARTIAL POSTERIOR VITREOUS DETACHMENT OVER TIME.

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

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.

The effects of aging on the mechanical properties of the vitreous

The vitreous body is a viscoelastic gel-like network that fills the space between the lens and the retina in the eye. With aging, the vitreous undergoes a liquefaction process in which liquid pockets form in the gel network, thereby motivating the detachment of the vitreous from the retina in a process known as posterior vitreous detachment (PVD). The PVD process may lead to the formation of floaters and even result in partial or complete loss of vision. Experiments show that the liquefaction and the PVD processes alter the mechanical properties of the vitreous. In this work, we propose a microscopically motivated model that characterizes the changes in the mechanical properties of the vitreous due to aging. To this end, we distinguish between four vitreous states: a homogeneous vitreous, a liquefied vitreous, a vitreous that undergoes partial PVD, and a vitreous with full PVD. The model predicts the time-dependent and the steady-state response of the vitreous in each of the four states. The proposed framework is validated through a comparison with various experimental findings and captures the softening of the vitreous due to aging. We illustrate the importance of the age at which the PVD process begins and of the rate of the detachment process. In addition, we introduce a quantifiable parameter that describes the stage of PVD in the eye. Lastly, we employ our model to investigate the possibility of restoring the mechanical properties of a vitreous that has undergone PVD through the addition of reinforcing fibers to the gel. This work provides insight into the consequences of the age-related changes in the microstructure of the eye and serves as a motivation for new therapeutic measures.

Частота витреоретинальной адгезии в области ретинальных сосудов у пациентов с осевой миопией различных возрастных групп

Purpose. Finding out the frequency and structures posterior vitreous detachment (PVD), the proportion of local vitreoretinal adhesion in topographical zones of large retinal vessels of posterior pole of the eye in patients of different age groups with axial myopia. Material and methods. Clinical material was 82 eyes (41 patients). The age of patients ranged from 18 to 70 years. According to the age category, which is determined by the WHO classification, all patients were divided into 3 groups. The 1st group (18-44 years old) included 12 people (24 eyes); the 2nd group (45–59 years old) included 14 people (28 eyes); the 3rd group (60–74 years old) included 15 people (30 eyes). Results. In the 1st group PVD was not detected in 11 eyes (45.8%); in 13 eyes there were various variants of PVD (54.2%). In the 2nd group PVD was not detected in 9 eyes (32.1%); in 19 eyes there were various variants of PVD (67.9%). In the 3rd group PVD was not detected in 5 eyes (16.7%); in 25 eyes (83.3%) there were various variants of PVD. In this group, there was statistically significant predominance of partial PVD with fixation of the posterior hyaloid membrane to inner limiting membrane (PHM to ILM). Conclusion. In the group of elderly patients with axial myopia (60– 75 years), statistically significant increase in incidence of local adhesion of PHM to ILM in the projection of large retinal vessels was revealed in comparison with young and middle-aged groups (10 cases versus 1 and 2, respectively, p<0.05). This feature must be taken in examination and subsequent management of these patients.