The effects of aging vitreous on contrast sensitivity function

Clinical Management of Vision Degrading Myodesopsia from Vitreous Floaters - Observation vs. Limited Refractive Vitrectomy

PURPOSE

To manage clinically significant vitreous floaters, called vision degrading myodesopsia, using objective quantification of vitreous structure and visual function, in order to distinguish cases that can be observed (OBS) from those that merit surgery, and define the profile of OBS patients.

DESIGN

Retrospective non-randomized interventional clinical study.

SUBJECTS

There were 651 eyes in 393 patients (220 men, 173 women; aged 57.3±14.7 years) with the chief complaint of floaters. Etiologies were posterior vitreous detachment (PVD; 252/651, 38.7%), myopic vitreopathy (MV; 133/651, 20.4%), and combined PVD+MV (210/651, 32.3%). Follow-up = 23.9 ± 29.0 months.

METHODS

Observation alone was performed in 362 cases. Sutureless 25-gauge limited refractive vitrectomy (LRV) without surgical PVD was performed in 289 eyes.

MAIN OUTCOME MEASURES

Vitreous echodensity was measured by quantitative ultrasonography, contrast sensitivity (CS) with Freiburg Acuity Contrast Testing (%W); patient reported outcomes with NEI Visual Function Questionnaire (VFQ-25).

RESULTS

OBS was chosen in 362/651 (55.6%; mean age 55.0 years), and LRV was elected in 289/651 (44.4%; mean age 60.1 years). OBS cases had 43.7% less vitreous echodensity (688 ± 170 AU vs. 1222 ± 356 AU; p<0.0001), 35.7% better CS (2.90±1.33 %W vs. 4.51±1.56 %W; p<0.0001), and better VFQ-25 (79.2±6.0 vs. 77.2±5.2; p<0.01). Subjects initially choosing OBS who converted to surgery >1 year later had comparable CS to the OBS group at study entry, which worsened prior to electing LRV. Post-operatively, echodensity decreased by 59.6% (to 494±64 AU, p<0.0001), CS improved by 45.7% (to 2.45±1.12%W, p<0.0001), and VFQ-25 improved by 6.3% (to 82.0±9.0, p<0.0001). Sequelae of LRV included vitreous hemorrhage (0.7%), retinal tears (2.8%), retinal detachment (2.4%), macular pucker surgery (1.4%), recurrent floaters (5.2%), and cataract surgery [35.8%; average age = 62.7±6.7years, 23.7±25.7 months post-vitrectomy; below age 50 only 3/37 (8.1%) underwent cataract surgery (follow-up = 28.9±35 months)].

CONCLUSIONS

Patients with vision degrading myodesopsia from vitreous floaters can be managed by observation or vitrectomy. Objective quantitative measures of vitreous echodensity and contrast sensitivity aid patient selection for observation. These patients were younger and phakic, had floaters from myopic vitreopathy without PVD, and had less vitreous echodensity, as well as better contrast sensitivity.

Diagnostic ability of confocal scanning ophthalmoscope for the detection of concurrent retinal disease in eyes with asteroid hyalosis

PURPOSE

To compare the diagnostic capacity of a color fundus camera (CFC), ultra-wide-field bicolor confocal scanning laser ophthalmoscope (BC-cSLO; OPTOS), and true-color confocal scanning ophthalmoscope (TC-cSO; EIDON) in detecting coexisting retinal diseases in eyes with asteroid hyalosis (AH).

METHODS

The medical records of consecutive patients with AH who were referred to a tertiary hospital for subsequent assessment by a vitreoretinal specialist were retrospectively reviewed. Fundus images obtained simultaneously using CFC, BC-cSLO, and TC-cSO were classified into four grades based on their obscuration by asteroid bodies. The proportion of Grade 1 images (minimal obscuration group) was assessed for each imaging modality. The diagnostic and screening abilities for concurrent retinal diseases were compared in terms of the accuracy and sensitivity of each device.

RESULTS

Among the 100 eyes with AH, 76 had coexisting retinal diseases, such as diabetic retinopathy (DR), retinal vascular occlusion, age-related macular degeneration, epiretinal membrane, and retinitis pigmentosa. TC-cSO had the highest ratio of Grade 1 images (94%, P<0.001), followed by CFC (67%) and BC-cSLO (63%). CFC and BC-cSLO exhibited a 5.3-fold higher rate of significant obscuration than TC-cSO (P<0.001, 95% confidence intervals = 2.4~11.6 folds). TC-cSO demonstrated the highest accuracy and sensitivity (95% and 81%, respectively) compared with CFC (89% and 43%, respectively) and BC-cSLO (89% and 39%, respectively) for all retinal diseases. BC-cSLO showed the best performance for DR diagnosis.

CONCLUSIONS

TC-cSO images showed minimal obscuration and a superior ability for diagnosing retinal diseases accompanied by AH over other imaging devices. TC-cSO can be a valuable alternative screening tool for detecting retinal diseases when AH impedes fundus imaging.

Carbon quantum dots for the diagnosis and treatment of ophthalmic diseases

Carbon quantum dots (CQDs), an emerging nanomaterial, are gaining attention in ophthalmological applications due to their distinctive physical, chemical, and biological characteristics. For example, their inherent fluorescent capabilities offer a novel and promising alternative to conventional fluorescent dyes for ocular disease diagnostics. Furthermore, because of the excellent biocompatibility and minimal cytotoxicity, CQDs are well-suited for therapeutic applications. In addition, functionalized CQDs can effectively deliver drugs to the posterior part of the eyeball to inhibit neovascularization. This review details the use of CQDs in the management of ophthalmic diseases, including various retinal diseases, and ocular infections. While still in its initial phases within ophthalmology, the significant potential of CQDs for diagnosing and treating eye conditions is evident.

Impaired Visual Function in Posterior Vitreous Detachment Assessed With the Active-Learning Quantitative Contrast Sensitivity Function Test

Introduction: To investigate whether there is visual function impairment in patients with posterior vitreous detachment (PVD) using the active-learning quantitative contrast sensitivity function test. Methods: In this cross-sectional study, contrast sensitivity was measured in eyes with PVD and eyes without PVD using the quantitative contrast sensitivity function algorithm on the Adaptive Sensory Technology platform. Outcomes included the area under the log contrast sensitivity function curve, contrast acuity, and contrast sensitivity thresholds at 1 to 18 cycles per degree (cpd). Snellen visual acuity (VA) was also measured. Mixed-effects multiple linear regression analyses were performed to evaluate the association between the presence of PVD and visual function, controlling for age and lens status. Results: The cohort comprised 232 healthy eyes of 205 participants; of these, 80 eyes of 69 patients had PVD. There was no significant association between VA and PVD presence. However, PVD was significantly associated with decreased contrast sensitivity thresholds at 1.5 cpd (β, -0.058; P = .003) and 3 cpd (β, -0.067; P = .004). Contrast sensitivity thresholds at lower (1 cpd) or higher (6, 12, 18 cpd) spatial frequencies did not significantly correlate with PVD presence. Even in the subgroup of symptomatic PVD eyes, VA was not significantly decreased, while quantitative contrast sensitivity function outcomes showed visual function deficits at low spatial frequencies (1.5 cpd and 3 cpd). Conclusions: Contrast sensitivity measured with the quantitative contrast sensitivity function test showed visual function deficits in eyes with PVD that would have been missed with VA testing alone. Incorporating this test in the retina clinic might offer a more comprehensive functional assessment of eyes with PVD, serving as an adjunct outcome metric in clinical decision-making.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Translational Relevance

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

Impact of posterior vitreous detachment on visual acuity after the implantation of a diffractive multifocal intraocular lens

PURPOSE

To investigate the effect of posterior vitreous detachment (PVD) on visual acuity (VA) after implantation of a diffractive multifocal intraocular lens (mIOL).

SETTING

Eye Clinic, Okayama, Japan.

DESIGN

Retrospective case series.

METHODS

This study evaluated 475 eyes of 475 patients who underwent cataract surgery with a TECNIS Multifocal ZLB00 lens implant between November 2017 and October 2019. Patient eyes were classified into the complete PVD group (PVD group) or the control group with no PVD/partial PVD (non-PVD group) and divided into 3 age categories: 65 to 69, 70 to 74, and 75 to 79 years. The postoperative VA of the PVD and non-PVD groups was compared between and within groups by age.

RESULTS

Distance-corrected near VA (DCNVA) was significantly worse in the PVD group than in the non-PVD group in all age categories ( P ≤ .029). In the PVD group, both corrected distance VA (CDVA) and DCNVA were significantly worse in the 75 to 79 years age group than in the 65 to 69 and 70 to 74 years age groups ( P ≤ .034). CDVA and DCNVA in the non-PVD group did not differ significantly between age categories.

CONCLUSIONS

The results of this study suggest that complete PVD worsens near VA in eyes with a diffractive mIOL. Furthermore, eyes with complete PVD may show an age-related decline in both CDVA and DCNVA. In particular, eyes ≥75 years of age with complete PVD have a poor visual prognosis and should be given careful consideration when deciding whether to implant a diffractive mIOL.

Quantitative Contrast Sensitivity Function and the Effect of Aging in Healthy Adult Eyes: A Normative Database

BACKGROUND AND OBJECTIVE

We sought to establish normative quantitative contrast sensitivity function (qCSF) values in healthy adult eyes and investigate the effect of age on qCSF.

PATIENTS AND METHODS

Healthy eyes underwent qCSF testing (adaptive sensory technology) and Snellen's visual acuity (VA). Descriptive statistics and mixed-effects multivariable linear regressions were evaluated.

RESULTS

A total of 334 eyes (290 patients) with median age 61 years (range 21 to 88) had qCSF values as follows: area under the log contrast sensitivity function curve: 1.18; contrast acuity: 1.32; contrast sensitivity (CS) at 1 cycle per degree (cpd): 1.32; CS at 1.5 cpd: 1.37; CS at 3 cpd: 1.38; CS at 6 cpd: 1.20; CS at 12 cpd: 0.69; CS at 18 cpd: 0.22. Linear reductions in qCSF values per decade of age ranged from -0.02 to -0.07 vs 0.01 for visual acuity (VA). Age had a greater effect on the majority of qCSF values than VA (beta standardized regression coefficient ranged from -0.309 to -0.141 for qCSF values vs 0.177 for VA).

CONCLUSIONS

We herein establish a normative database for qCSF and quantify the effect of age on qCSF values, adding evidence towards the validation of qCSF as a clinical endpoint. [Ophthalmic Surg Lasers Imaging Retina 2024;55:212-219.].

Practical applications of vitreous imaging for the treatment of vitreous opacities with YAG vitreolysis

PURPOSE

To demonstrate the methodology and efficacy of using scanning laser ophthalmoscopy (SLO) and dynamic optical coherence tomography (OCT) to identify and treat symptomatic vitreous floaters using yttrium-aluminum garnet laser vitreolysis (YLV).

METHODS

This is a case series highlighted from a cross sectional retrospective study conducted at the Vitreous Retina Macula Specialists of Toronto. Forty eyes from thirty-five patients were treated with YLV between November 2018 and December 2020 for symptomatic floaters and imaged with SLO and dynamic OCT. Patients were re-treated with YLV if they reported ongoing significant vision symptoms during follow-up which correlated to visible opacities on exam and or imaging. Three cases will be highlighted to present the practical applications of SLO and dynamic OCT imaging for YLV treatment.

RESULTS

Forty treated eyes were enrolled in this study, with twenty-six eyes (65%) requiring at least one repeat YLV treatment following the first treatment due to ongoing symptomatic floaters. Following the first YLV, there was a significant improvement in overall mean best corrected visual acuity compared to before treatment (0.11 ± 0.20 LogMAR units vs. 0.14 ± 0.20 LogMAR units, p = 0.02 (paired t test)). Case 1 demonstrates a dense, solitary vitreous opacity that has been localized with dynamic OCT imaging to track its movements and retinal shadowing with the patient's eye movements. Case 2 shows the utility of adjusting the fixation target to monitor the movement of vitreous opacities in real-time. Case 3 exhibits an association between decreased symptom burden and vitreous opacity density after YLV.

CONCLUSION

Image-guided YLV facilitates the localization and confirmation of vitreous opacities. SLO and dynamic OCT of the vitreous can provide a real-time evaluation of floater size, movement, and morphology, to help clinicians target treatment and monitoring of symptomatic floaters.

Machine Independence of Ultrasound-Based Quantification of Vitreous Echodensities

Purpose

Quantitative ultrasound (QUS) provides objective indices of Vision Degrading Myodesopsia (VDM) that correlate with contrast sensitivity (CS). To date, QUS methods were only tested on a single ultrasound machine. Here, we evaluate whether QUS measurements are machine independent.

Methods

In this cross-sectional study, 47 eyes (24 subjects; age = 53.2 ± 14.4 years) were evaluated with Freiburg acuity contrast testing (%Weber), and ultrasonography using 2 machines: one with a 15-MHz single-element transducer and one with a 5-ring, 20-MHz annular-array. Images were acquired from each system in sequential scans. Artifact-free, log-compressed envelope data were processed to yield three parameters (mean amplitude, M; energy, E; and percentage filled by echodensities, P50) and a composite score (C). A B-mode normalization method was applied to the 20-MHz datasets to match QUS parameters at both frequencies. Statistical analyses were performed to evaluate correlations among CS, E, M, P50, and C for both machines.

Results

QUS parameters from each machine correlated with CS (R ≥ 0.57, P < 0.001) and there was correlation between machines (R ≥ 0.84, P < 0.001). Correlations between CS and QUS parameters were statistically similar for both machines (P ≥ 0.14) except when the 20-MHz data were normalized (P = 0.04). Reproducibility of QUS parameters computed from 20-MHz data were satisfactory (52.3%-96.3%) with intraclass correlation values exceeding 0.80 (P < 0.001).

Conclusions

The high correlation between QUS parameters from both machines combined with a statistically similar correlation to CS suggests QUS is an effective, machine-independent, quantitative measure of vitreous echodensities.

Translational Relevance

QUS may be applied across clinical ophthalmic ultrasound scanners and imaging frequencies to effectively evaluate VDM.

RECURRENT FLOATERS AFTER LIMITED VITRECTOMY FOR VISION DEGRADING MYODESOPSIA

PURPOSE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Vitrectomy Improves Contrast Sensitivity in Multifocal Pseudophakia With Vision Degrading Myodesopsia

PURPOSE

Multifocal intraocular lenses (MFIOL) are associated with degradation in contrast sensitivity function (CSF); yet the contribution of vitreous is not known, nor is the benefit of vitrectomy.

DESIGN

Prospective, nonrandomized clinical study.

METHODS

A total of 180 eyes of 180 patients (55 MFIOL, 60 monofocal intraocular lenses [MIOL], 65 phakic) with symptomatic vitreous opacities were enrolled. Vitreous structure was assessed with quantitative ultrasonography (QUS). Vision was evaluated with visual acuity and CSF measurements.

RESULTS

Vitreous echodensity was the same in all lens cohorts, yet CSF was worse in MFIOL eyes (P < .001). In 86 patients who elected vitrectomy, there was 68% greater vitreous echodensity and 31% worse CSF than in observation controls (P < .0001 for each). Preoperatively, CSF was 25% worse in MFIOL than in MIOL (P = .014). Postoperatively, vitreous echodensity decreased by 55%, 51%, and 52%, whereas CSF improved by 37% 48% in and 43% in MFIOL, MIOL, and phakic eyes, respectively (P < .0001 for each). NEI Visual Function Questionnaire analyses showed improved visual well-being.

CONCLUSIONS

Patients with vision degrading myodesopsia who elected vitrectomy had greater vitreous echodensity and worse CSF than controls, but no other differences in age, sex, or myopia. MFIOL eyes had worse CSF than MIOL and phakic eyes, very possibly due to combined effects of the MFIOL and vitreous opacification. Limited vitrectomy reduced vitreous echodensity and improved CSF in all eyes. All patients with CSF-degrading vitreous opacities benefited from limited vitrectomy, including those with MFIOL. As MFIOL eyes had 37% improvement in CSF, patients with MFIOL and vision degrading myodesopsia merit consideration of vitrectomy.

The effectiveness of laser vitreolysis for vitreous floaters in posterior vitreous detachment

Purpose

To determine the effectiveness of laser vitreolysis in terms of contrast sensitivity function (CSF) and vision-related quality of life (VRQol) for symptomatic floaters due to posterior vitreous detachment (PVD).

Materials

This is an interventional study that involved 57 eyes of 45 patients with symptomatic floaters for more than 3 months. Patients underwent one to three sessions of vitreolysis via Neodymiun-doped Yttrium Aluminum Garnet (Nd:YAG) laser. We examined the CSF using the computer programs Freiburg Acuity and Contrast Test (FrACT) and VRQoL survey using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) before, and 1 month after, vitreolysis.

Results

Twelve patients had both eyes lasered and 33 patients had one eye lasered. The mean CSF improved from 3.20 ± 0.85%W to 2.64 ± 0.63%W 1 month after vitreolysis. Each use of the laser showed a significant mean difference in CSF (%W) as analyzed by paired t-test before and after the first laser (0.29 ± 0.49%W [P ≤ 0.001]); after the first and second laser (0.35 ± 0.53%W [P = 0.01]); and after second and third laser (0.21 ± 0.31%W [P = 0.02]). There was improvement in the median of four subscales in NEI VFQ-25 scores post treatment: general vision (z = -3.30, P = 0.001), near activity (z = 3.396, P = 0.001, distance activity (z = -2.788, P = 0.005), and mental health (z = -2.219, P = 0.026). The mean scores increased to 79.55 ± 9.45 from the baseline 75.06 ± 9.69 (P ≤ 0.001). No adverse events were recorded 1 month after the laser treatments.

Conclusion

Vitreolysis by Nd:YAG laser improved the CFS and VRQoL in symptomatic PVD patients.

Impact of symptomatic vitreous degeneration on photopic and mesopic contrast thresholds

CLINICAL RELEVANCE

Contrast thresholds under photopic and mesopic luminance conditions are compromised in subjects with vitreous degeneration. A plausible explanation is needed for the visual discomfort expressed by patients suffering from symptomatic vitreous degeneration.

BACKGROUND

The current study investigates the effect of symptomatic vitreous degeneration on photopic and mesopic contrast at high spatial frequencies.

METHODS

An age-matched sample of 115 subjects, comprising 30 subjects with symptomatic vitreous floaters (cases) and 85 healthy subjects (controls), was included in this study. Visual acuity and flicker thresholds were measured for all participants. Photopic and mesopic functional contrast thresholds at 10 cycles per degree were measured for all participants to assess the effect of floaters on contrast. Further, to determine the effect of posterior vitreous detachment on contrast, the sample was divided into three groups: cases with posterior vitreous detachment (n = 12); cases without posterior vitreous detachment (n = 18); and controls (n = 85), and their contrast thresholds were compared.

RESULTS

Photopic and mesopic contrast thresholds were lower by 37.4% and 27.5%, respectively, when the cases were compared with the controls (p = 0.028 and p < 0.001 for photopic and mesopic contrast thresholds, respectively). Photopic contrast was lower by 64.0% in cases with posterior vitreous detachment compared with controls (p = 0.001). Compared with controls, mesopic contrast was lower in cases with posterior vitreous detachment and in cases without posterior vitreous detachment by 30.3% and 25.6%, respectively (p = 0.014 and p = 0.017 for cases with and without posterior vitreous detachment, respectively).

CONCLUSION

: Subjects with vitreous degeneration have diminished photopic and mesopic contrast thresholds compared with controls. This finding highlights the negative impact of vitreous degeneration on the quality of vision.

Preoperative Factors Affecting Visual Acuity Following the Implantation of Diffractive Multifocal Intraocular Lenses

PURPOSE

To investigate the preoperative factors affecting visual acuity after the implantation of a diffractive multifocal intraocular lens.

METHODS

This study evaluated 774 eyes of 774 patients who underwent cataract surgery with TECNIS Multifocal ZLB00 lens (Johnson & Johnson Surgical Vision) implantation. Anterior segment optical coherence tomography (CASIA2; Tomey Corporation) was performed as a part of the preoperative eye examination. Sex, age, axial length, and CASIA2 parameters, such as crystalline lens diameter and lens tilt relative to the corneal topographic axis, were investigated. The eyes considered were classified into good (20/20 or better) or poor (worse than 20/20) far vision groups based on corrected distance visual acuity, and good (20/25 or better) or poor (worse than 20/25) near vision groups based on distance-corrected near visual acuity, respectively. Preoperative characteristics of both groups were compared to determine factors affecting postoperative visual acuity.

RESULTS

Multivariate logistic regression analysis revealed that older age (P < .001), a short axial length (P = .010), and a large lens tilt (P < .001) were associated with poor near vision. There was no significant difference between the two far vision groups. There was a significant negative correlation between lens tilt and axial length (r = -0.513, P < .001).

CONCLUSIONS

The results of this study suggest that age, axial length, and lens tilt to the corneal topographic axis may predict poor visual acuity after the implantation of a diffractive multifocal intraocular lens. Eyes with a short axial length tended to have a large degree of lens tilt and should be considered particularly carefully. [J Refract Surg. 2021;37(10):674-679.].

Dietary Intervention With a Targeted Micronutrient Formulation Reduces the Visual Discomfort Associated With Vitreous Degeneration

Purpose

To investigate the impact of supplementation with a targeted micronutrient formulation on the visual discomfort associated with vitreous degeneration.

Methods

In this clinical trial, 61 patients with symptomatic vitreous floaters were randomized to consume daily, the active supplement consisting of 125 mg L-lysine, 40 mg vitamin C, 26.3 mg Vitis vinifera extract, 5 mg zinc, and 100 mg Citrus aurantium or placebo for 6 months. Change in visual discomfort from floaters, assessed with the Floater Disturbance Questionnaire, was the primary outcome measure. Secondary outcome measures included best-corrected visual acuity, letter contrast sensitivity, photopic functional contrast sensitivity with positive and negative contrast polarity, and quantitative vitreous opacity areas.

Results

After supplementation, the active group reported a significant decrease in their visual discomfort from floaters (P < 0.001), whereas the placebo group had no significant change in their visual discomfort (P = 0.416). At 6 months, there was a significant decrease in vitreous opacity areas in the active group (P < 0.001) and an insignificant increase in vitreous opacity areas in the placebo group (P = 0.081). Also, there was a significant improvement in photopic functional contrast sensitivity with positive contrast polarity in the active group after supplementation (P = 0.047).

Conclusions

The findings of this study indicate improvements in vision-related quality of life and visual function of patients suffering from vitreous floaters after supplementation with a formulation of antioxidative and antiglycation micronutrients. Notably, these improvements were confirmed by the decrease in vitreous opacity areas in the active group.

Translational Relevance

This targeted dietary intervention should be considered to support patients with symptomatic vitreous degeneration.

Carbon quantum dots as a dual platform for the inhibition and light-based destruction of collagen fibers: implications for the treatment of eye floaters

Common in myopia and aging, vitreous opacities arise from clumped collagen fibers within the vitreous body that cast shadows on the retina, appearing as 'floaters' to the patient. Vitreous opacities degrade contrast sensitivity function and can cause significant impairment in vision-related quality-of-life, representing an unmet and underestimated medical need. One therapeutic approach could be the use of versatile light-responsive nanostructures which (i) interfere with the formation of collagen fibers and/or (ii) destroy aggregates of vitreous collagen upon pulsed-laser irradiation at low fluences. In this work, the potential of positively and negatively charged carbon quantum dots (CQDs) to interfere with the aggregation of type I collagen is investigated. We demonstrate that fibrillation of collagen I is prevented most strongly by positively charged CQDs (CQDs-2) and that pulsed-laser illumination allowed to destroy type I collagen aggregates and vitreous opacities (as obtained from patients after vitrectomy) treated with CQDs-2.

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.

Vitreous Structure and Visual Function in Myopic Vitreopathy Causing Vision-Degrading Myodesopsia

PURPOSE

Myopic vitreopathy features precocious fibrous vitreous liquefaction and early posterior vitreous detachment (PVD). It is unclear whether visual function is affected by myopic vitreopathy and PVD. This study assessed the relationships among axial length, structural vitreous density, PVD, and visual function.

DESIGN

Retrospective case-control study.

METHODS

Ultrasonography measurements were made of axial length, logMAR VA, contrast sensitivity function (CSF [Freiburg acuity contrast test]), and quantitative B-scan ultrasonography.

RESULTS

Seventy-nine subjects (45 men and 34 women; mean age: 49 ± 14 years) were analyzed. Axial lengths ranged from 22 to 29.2 mm (mean: 24.9 ± 1.8 mm; myopic eyes: 26.35 ± 1.35 mm; and nonmyopic eyes: 23.45 ± 0.75 mm; P < .001). With increasing axial length there was greater vitreous echodensity (R: 0.573; P < .01) and degradation in CSF (R: 0.611; P < .01). Subgroup analyses found that myopic eyes (>- 3 diopters) had 37% more vitreous echodensity than nonmyopic eyes (762 ± 198 arbitrary units [AU] vs. 557 ± 171 AU, respectively; P < .001) and that CSF was 53% worse in myopic eyes (3.30 ± 1.24 Weber index [%W]) than in nonmyopic eyes (2.16 ± .59 %W; P < .001). Myopic eyes with PVD had 33% greater vitreous echodensity (815 ± 217 AU; P < .001) and 62% degradation in CSF (3.63 ± 2.99 %W) compared to nonmyopic eyes with PVD (613 ± 159 AU; 2.24 ± 0.69 %W; P < .001, each). Limited vitrectomy was performed in 11 of 40 cases (27.5%), normalizing vitreous echodensity and CSF in each case.

CONCLUSIONS

Axial myopia is associated with increased fibrous vitreous liquefaction and echodensity, as well as profound degradation of CSF. PVD in myopic eyes is associated with even more structural and functional abnormalities, normalized by limited vitrectomy. These findings may explain some common complaints of myopic patients with respect to vision and quality 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.

To Treat or Not to Treat: Management Options for Symptomatic Vitreous Floaters

Vitreous floaters are a common cause for presentation to ophthalmologists, and may significantly affect visual function. In the absence of some more serious underlying pathology such as uveitis, many patients may not experience significant persistent visual impairment from floaters. For some patients, the symptomatic effects of floaters may persist. For these patients, treatment options are available, of which the most commonly reported is vitrectomy. Other treatment modalities have also become more common, notably YAG vitreolysis. Selection of appropriate patients for surgery is often difficult, in part due to the relative lack of objective outcomes with which to measure both visual impairment and improvement post-procedure. Although well-tolerated, vitrectomy does carry with it risks, including iatrogenic retinal breaks, retinal detachment, and in phakic patients, subsequent cataract formation. Techniques such as small gauge vitrectomy, intraoperative examination and treatment of breaks or other worrying lesions, and careful consideration of the need for posterior vitreous detachment induction may help limit the incidence of these adverse events. For other treatment options such as YAG vitreolysis, research and clinical experience remain more limited, and as such the long-term efficacy and risks of these therapies are still unclear. Here, we review the evidence surrounding the role of vitrectomy and YAG vitreolysis in the treatment of vitreous floaters and potential means to minimize therapeutic complications.

Cost-Effectiveness of Limited Vitrectomy for Vision-Degrading Myodesopsia

PURPOSE

Patients afflicted with clinically significant vitreous floaters suffer from vision-degrading myodesopsia, characterized by impairment in contrast sensitivity function (CSF) and decreased quality of life. This study determined the cost-effectiveness of limited vitrectomy for this condition.

DESIGN

Retrospective, interventional case series and third-party insurer cost-utility analysis.

METHODS

Sixty-seven patients suffering from unilateral vitreous floaters (20 non-myopic patients with posterior vitreous detachment [PVD]; 17 myopic patients [>-2 diopters] without PVD; 30 myopic patients with PVD) completed the National Eye Institute Visual Function Questionnaire (VFQ-39) and were tested with best-corrected visual acuity (BCVA) and CSF measurements before and after limited vitrectomy. A reference case cost-utility analysis was performed.

RESULTS

The mean VFQ-39 increased 19% (P < 0.00001) after surgery, with general vision improving 27% for the entire group and 37% for non-myopic PVD (P < 0.00001 for each). VFQ-39 correlations with time tradeoff utilities indicated a 14.4% improvement in quality of life. Mean BCVA improved 13.5% postoperatively (P < 0.00001) and CSF improved 53% (P < 0.00001). The incremental patient value gain conferred by limited vitrectomy was 2.38 quality-adjusted life-years (QALYs), and the average cost-utility ratio in 2018 U.S. real dollars was $1,574/QALY.

CONCLUSIONS

Limited vitrectomy for vision-degrading myodesopsia is clinically effective, in that it improves BCVA, CSF, and patient well-being. It is also highly cost-effective ($1,574/QALY), with an average cost-utility ratio vs. no therapy that is superior to cataract surgery ($2,262/QALY), amblyopia therapy ($2,710/QALY), and retinal detachment repair ($45,304/QALY). Myopic patients without PVD had the lowest cost-utility ratio of all ($1,338/QALY).

Assessment of Vitreous Structure and Visual Function after Neodymium:Yttrium-Aluminum-Garnet Laser Vitreolysis

PURPOSE

Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser treatment is performed on vitreous floaters, but studies of structural and functional effects with objective outcome measures are lacking. This study evaluated Nd:YAG laser effects by comparing participants with vitreous floaters who previously underwent laser treatment with untreated control participants and healthy persons without vitreous floaters using quantitative ultrasonography to evaluate vitreous structure and by measuring visual acuity and contrast sensitivity function to assess vision.

DESIGN

Retrospective, comparative study.

PARTICIPANTS

One eye was enrolled for each of 132 participants: 35 control participants without vitreous floaters, 59 participants with untreated vitreous floaters, and 38 participants with vitreous floaters previously Nd:YAG-treated. Of these, 25 were dissatisfied and sought vitrectomy; 13 were satisfied with observation.

METHODS

The 39-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-39) to assess participant visual well-being, quantitative ultrasonography (QUS) to measure vitreous echodensity, and best-corrected visual acuity (BCVA) and contrast sensitivity function (CSF) to evaluate vision.

MAIN OUTCOME MEASURES

Results of NEI-VFQ-39, QUS, BCVA, and CSF.

RESULTS

Compared with control participants without vitreous floaters, participants with untreated vitreous floaters showed worse NEI-VFQ-39 results, 57% greater vitreous echodensity, and significant (130%) CSF degradation (P < 0.001 for each). Compared with untreated eyes with vitreous floaters, Nd:YAG-treated eyes had 23% less vitreous echodensity (P < 0.001), but no differences in NEI-VFQ-39 (P = 0.51), BCVA (P = 0.42), and CSF (P = 0.17) results. Of 38 participants with vitreous floaters who previously were treated with Nd:YAG, 25 were dissatisfied and seeking vitrectomy, whereas 13 were satisfied with observation. Participants seeking vitrectomy showed 24% greater vitreous echodensity (P = 0.018) and 52% worse CSF (P = 0.006). Multivariate linear regression models confirmed these findings.

CONCLUSIONS

As a group, participants previously treated with Nd:YAG laser for bothersome vitreous floaters showed less dense vitreous, but similar visual function as untreated control participants with vitreous floaters. Because some treated eyes showed less dense vitreous and better visual function than those of untreated control participants, a prospective randomized study of Nd:YAG laser treatment of vitreous is warranted, using uniform laser treatment parameters and objective quantitative outcome measures.

Asteroid hyalosis-a comprehensive review

Asteroid hyalosis is a relatively common cause of vitreous opacities, which is possibly associated with diabetes mellitus and hereditary pigmentary retinopathies. We review the history, epidemiology, and biochemistry of asteroid hyalosis, as well as its relationship with ocular and systemic conditions. We describe imaging modalities used for diagnostic evaluations in cases of severe asteroid hyalosis and propose hypotheses regarding its lack of significant effects on vision. We discuss cataract surgery in patients with asteroid hyalosis and the selection of intraocular lenses for implantation.

Long-Term Safety and Efficacy of Limited Vitrectomy for Vision Degrading Vitreopathy Resulting from Vitreous Floaters

PURPOSE

Vitreous floaters can lower visual acuity (VA) and degrade contrast sensitivity function (CSF). Limited vitrectomy improves VA and normalizes CSF, but long-term results in a large series with objective quantitative outcome measures are lacking.

DESIGN

Case series.

PARTICIPANTS

One hundred ninety-five eyes of 145 patients (87 men, age = 57.6 ± 4.3 years; 58 women, age = 61.5 ± 12.0 years) reporting bothersome vitreous floaters were compared to 70 age-matched controls. Posterior vitreous detachment (PVD) alone was the cause in 96/195 (49.2%), myopic vitreopathy alone was the cause in 30/195 (15.4%), PVD with myopic vitreopathy was the cause in 56/195 (28.7%), and asteroid hyalosis was the cause in 13/195 eyes (6.7%).

METHODS

Limited vitrectomy with 25-gauge instruments was performed without surgical PVD induction, preserving 3 to 4 mm of retrolental vitreous in phakic eyes. Follow-up averaged 32.6 ± 23.5 months (range, 3-115 months), with 2 years or more in 144 eyes, 3 years or more in 69 eyes, 4 years or more in 51 eyes, and 5 years or more in 24 eyes.

MAIN OUTCOME MEASURES

Visual acuity, 39-item National Eye Institute Visual Function Questionnaire (VFQ) results, CSF (Weber index), and quantitative ultrasonography results.

RESULTS

After surgery, vitreous echodensity decreased by 94.1% (P < 0.0001) and VFQ results improved by 19.3% (P < 0.0001). Preoperative VA was 0.68 ± 0.21, improving to 0.77 ± 0.19 after surgery (P < 0.0001). Preoperative CSF was degraded by 91.3% compared with controls (P < 0.0001), normalizing at 1, 3, 6, 12, 24, 36, and 48 months after surgery (P < 0.00005 for each). There were no cases of endophthalmitis. There were 3 retinal tears and 3 retinal detachments that underwent successful repair. Clinically significant vitreous hemorrhage developed in 2 patients, clearing spontaneously. Two macular puckers and 4 recurrent floaters from new PVD were cured by re-operation. Cataract surgery occurred in 21 of 124 patients (16.9%; mean age, 64 ± 7 years; none younger than 53 years), an average of 13.1 ± 6.8 months after vitrectomy.

CONCLUSIONS

Limited vitrectomy for Vision Degrading Vitreopathy decreases vitreous echodensity, improves patient well-being, improves VA, and normalizes CSF. The long-term efficacy and safety profiles suggest this may be a safe and effective treatment for clinically significant vitreous floaters, warranting a prospective randomized trial.