Vitrectomy for primary symptomatic vitreous opacities: an evidence-based review

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.

Spontaneous remission of vision degrading myodesopsia of posterior vitreous detachment type

PURPOSE

The study aims to observe the spontaneous remission of posterior vitreous detachment (PVD)-type vision degrading myodesopsia (VDM) during long-term follow-up.

METHODS

We retrospectively reviewed VDM patients with PVD type that refused any treatment. The ratio and time of significant spontaneous remission of floater symptoms occurring were described. The associated factors with significant remission of floater symptoms were analyzed in the univariate and multivariate logistic regression analyses.

RESULTS

In total, 179 patients with VDM were assessed. The mean age of all patients was 60.56 ± 0.47 years old, and the mean duration of follow-up was 23.89 ± 6.63 months. Of the patients, 40.78% have significant improvement in their floater symptoms after mean 16.55 ± 10.63-month follow-up. Myopia (OR = 0.280, 95% CI = 0.084-0.932, P = 0.038), the number of floaters > 3 (OR = 0.343, 95% CI = 0.172-0.683, P = 0.002), and floaters with string-like pattern (OR = 0.370, 95% CI = 0.166-0.824, P = 0.015) and blocky pattern (OR = 0.299, 95% CI = 0.090-0.993, P = 0.049) were negatively correlated with the significant spontaneous remission of VDM symptoms in the multiple binary logistic regression analysis.

CONCLUSIONS

Approximately 40% of VDM patients with PVD may experience significant spontaneous remission during long-term follow-up. Patients that are non-myopic and with fewer floaters are more likely to feel relief from VDM symptoms. Floaters with string-like or blocky patterns are less likely to undergo spontaneous remission.

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.

A New Pharmacological Vitreolysis through the Supplement of Mixed Fruit Enzymes for Patients with Ocular Floaters or Vitreous Hemorrhage-Induced Floaters

Purpose: Ocular floaters caused by vitreous degeneration or blood clots may interfere with various visual functions. Our study investigated the pharmacologic effects of oral supplementation of mixed fruit enzymes (MFEs) for treating spontaneous symptomatic vitreous opacities (SVOs) and those secondary to vitreous hemorrhage (VH). Methods: 224 patients with monocular symptomatic vitreous opacities (SVOs) were recruited between September and December 2017 and received oral supplementation of MFEs (190 mg bromelain, 95 mg papain, and 95 mg ficin) for 3 months in a double-blind clinical trial. Participants were divided according to the etiology of the SVOs, spontaneous (experiment 1) versus VH (experiment 2), and then randomly assigned into four treatments groups: one group received oral vitamin C, as a placebo; and the other 3 groups received 1 capsule per day (low dose), 2 capsules per day (middle dose), or 3 capsules per day (high dose) of MFEs. The number of SVOs was determined at baseline and then 1, 2, and 3 months after initiating treatment. Further, in cases secondary to VH, the changes in corrected distance visual acuity (CDVA) were assessed after 3 months. Second, we compared the free radical scavenging capabilities of each substance: vitamin C, bromelain, papain, ficin, and MFEs (combination of bromelain, papain, and ficin) by DDPH assay. Finally, SVOs-related symptoms and satisfaction with the treatments were evaluated at the last follow-up visit Results: In experiment 1, the disappearance rate of SVOs was 55%, 62.5%, and 70% after taking 1, 2, and 3 capsules daily, respectively (total p < 0.001), in a dose-dependent manner. In experiment 2, the disappearance rate of VH-induced SVOs was 18%, 25%, and 56% (p < 0.001) after 1, 2, and 3 capsules of the supplement daily, respectively. Additionally, the patients’ vision elevated from 0.63LogMAR to 0.19LogMAR (p = 0.008). Conclusions: A pharmacological approach using a high dose of oral supplementation with MFEs (bromelain, papain, and ficin) was effective in reducing vitreous opacities, even after intraocular hemorrhage. Furthermore, pharmacologic vitreolysis with MFEs supplementation showed high patient satisfaction, and also improved CDVA in patients with vitreous hemorrhage-induced floaters

Visualization and Grading of Vitreous Floaters Using Dynamic Ultra-Widefield Infrared Confocal Scanning Laser Ophthalmoscopy: A Pilot Study

Purpose: To describe the appearance of vitreous opacities using dynamic ultra-widefield infrared confocal scanning laser ophthalmoscopy (IRcSLO). Design: Retrospective case series. Methods: Eyes of patients complaining of myodesopsia were analyzed using dynamic ultra-widefield IRcSLO imaging (Nidek Mirante, Nidek Co., Ltd., Gamagori, Japan), and classified according to a vitreous opacity severity scale. Results: Thirty eyes of 21 patients were included in this study. The average age was 56 years. Symptom duration ranged from 1 to more than 365 days. The most common cause of vitreous floaters was posterior vitreous detachment (63.3%), followed by vitreous syneresis (23.3%), asteroid hyalosis (10%) and vitreous hemorrhage (3.3%). Opacities were classified as Grade 1 in three eyes (10%), Grade 2 in 10 eyes (33.3%), Grade 3 in 11 eyes (36.6%), Grade 4 in two eyes (6.6%) and Grade 5 in four eyes (13.3%). Patients with Grade 1 opacities were younger than patients with opacities Grade 2 or greater. A visible Weiss ring could be identified in 0% of eyes with Grade 1 opacities, 40% of eyes with Grade 2 opacities, 100% of eyes with Grade 3 opacities, and 100% of eyes with Grade 4 opacities. In patients with Grade 5 opacities, a Weiss ring could not be identified. Conclusion: Dynamic ultra-widefield IRcSLO imaging is a useful tool to evaluate patients with vitreous floaters. It allows for accurate visualization of the number, density, and behavior of the shadows that vitreous opacities project over a very wide area of the retina, which has a positive correlation with patient perception of floaters.

Vitreous Opacity Vitrectomy (VOV): Safest Possible Removal of “Floaters”

Purpose

Primary opacities that develop in the aging vitreous, commonly termed “floaters,” were once considered merely a nuisance, not justifying any risk of surgical removal. However, vitreoretinal specialists are increasingly recognizing that extensive symptomatic vitreous opacities (SVO) that substantially interfere with activities that critically depend on vision (daily visual activities, DVA), constituting degenerative vitreous syndrome (DVS, see http://floaterstories.com), warrant removal albeit with minimal risk - but no description of how to reduce vitrectomy risks to least possible has been forthcoming. We here describe such a method.

Patients and Methods

The safest possible removal of extensive SVO as described herein was attained by an operation specifically designed for DVS treatment (vitreous opacity vitrectomy, VOV), rather than as only a means of achieving subsequent retinal surgery in the same procedure, as is usually the case. We retrospectively reviewed the outcomes of 100 consecutive VOV operations (in 81 patients, average age 66) performed with ultra-high speed, 27-gauge vitrectomy probes.

Results

All eyes rapidly achieved continuously clear vision, and no eye developed a clinically significant complication during a year of follow-up. Three small, existent retinal breaks were discovered prior to peripheral vitrectomy and one apparently iatrogenic retinal tear was found at VOV completion, when each was treated. In the eyes that were not pseudophakic, postoperative nuclear sclerosis progression was successfully managed by subsequent cataract extraction.

Conclusion

The goals of VOV for DVS are to safely restore continuously clear vision by performing tractionless vitreous removal with respect to the retina and to reduce the lifetime risk of retinal detachment, both by such vitreous removal and by microscopic examination of the peripheral retina under anesthesia (MEPRUA), guiding appropriate prophylactic retinopexy. The otherwise healthy DVS eyes so treated warrant this specific form of vitrectomy, continually focused on achieving least possible risk, to maintain an acceptable risk/benefit ratio.

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Psychological implications of vitreous opacities - A systematic review

QUESTION

Given that depression and anxiety can be comorbid to several treatable eye diseases, it is paramount to understand whether vitreous opacities are also associated with increased risk of well-being and mental health problems. The current systematic review summarises research examining psychological implications of vitreous opacities in adult patients.

STUDY SELECTION AND ANALYSIS

PubMed, Cochrane library, EMBASE, Global Health, Web of Science, EBSCO, and Science Direct were systematically searched for all articles published up to May 5th 2021. Inclusion criteria included studies that have assessed outcomes related to patients' mental health; well-being; quality of life; coping with the disease; studies exploring patients' experiences/perceptions/cognitions of illness and/or medical treatments related to vitreous opacities.

FINDINGS

5 studies were included in this review, with a total of 139 patients [278 eyes] assessed. Patients' age ranged from 32 to 78 years old. Compared with healthy controls, patients with vitreous opacities showed significantly higher levels of symptoms of depression, perceived stress, state anxiety, and trait anxiety. Studies also suggested that patients are more likely to show low vision-related quality of life, and social functioning. Studies also suggested a significant positive effect of medical treatments [e.g. pars plana victretomy] on patients' symptoms of depression and anxiety and on patients' vision-related quality of life.

CONCLUSIONS

The topic of psychological implications of vitreous opacities is still relatively new in the literature with very preliminary evidence of mental health problems and reduced quality of life associated with this condition.

Optical Scattering from Vitreous Floaters

Vitreous “floaters” are a common entoptic phenomenon that can result in significant reduction in quality of life in a proportion of sufferers. The authors use a computational mathematical model based on Fourier optics and reflection and transmission coefficients calculated for a planar type II collagen opacity suspended in aqueous to show that floaters are perceived by the patient through interference effects that result in significant variations in intensity on the retina when viewing a constant brightness surface. The model also predicts that backscattered intensity from floaters is ten thousand to one million times lower than the variations in intensity produced on the retina, which demonstrates that the visible effects of floaters for the patient can be highly significant, whereas clinical observation of the vitreous may be entirely unremarkable. Importantly, the results also demonstrate that floaters do not need to be opaque to cause symptoms, with only small differences in refractive index between the floater material and the surrounding vitreous needed to produce significant optical effects. The model predicts that pupil size is an important factor in determining the severity of symptoms from floaters, with constricted pupils giving much greater effect than dilated pupils. Finally, the authors’ model predicts that floaters degrade contrast sensitivity function, with greatest degradation occurring in the 5–40 cycles per degree spatial frequency range and that the effects of shadowing caused by floaters are very strongly correlated to the predicted degradation of contrast sensitivity function. Bioelectromagnetics. 43:90–105, 2022. © 2021 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society.

The Efficacy and Safety of YAG Laser Vitreolysis for Symptomatic Vitreous Floaters of Complete PVD or Non-PVD

INTRODUCTION

To evaluate and compare the efficacy and safety of YAG laser vitreolysis in treating symptomatic vitreous floaters of complete posterior vitreous detachment (PVD) and non-PVD.

METHODS

In this prospective cohort study, 51 eyes with symptomatic floaters were treated with YAG laser vitreolysis. Participants were divided into complete PVD and non-PVD groups. Objective visual quality measures including the Strehl ratio (SR), internal spherical aberration (SA), internal comatic aberration (CA), internal high-order aberration (HOA), area ratio of modulation transfer function (MTFa) and Vitreous Floaters Symptom Questionnaire (VFSQ-13) scores were used to compare the efficacy of YAG laser vitreolysis treatment between two groups.

RESULTS

The mean age of all patients was 56.80 ± 10.82 years old. In total, 36 of 51 (70.59%; 95% CI 58.10-83.10) patients reported their symptoms as significant or complete improvement after YAG laser vitreolysis treatment. Post-treatment MTFa, internal SA and internal HOA were significantly better compared to baseline (26.19 ± 14.73 vs. 29.19 ± 17.98, p = 0.013; 0.05 ± 0.05 vs. 0.04 ± 0.04, p = 0.031 and 0.23 ± 0.22 vs. 0.16 ± 0.07, p = 0.044; respectively) in all eyes. Twenty-nine of 51 (56.86%) eyes had floaters of non-PVD type. Significant or complete subjective improvements in the PVD group and non-PVD group were 72.73% and 68.97% (p = 0.344), respectively.

CONCLUSIONS

Improved subjective and objective visual quality in participants with symptomatic floaters following YAG laser vitreolysis was found in both groups. The efficacy of YAG laser vitreolysis was comparable in floaters of complete PVD and non-PVD types.

Evaluation of Available Online Information Regarding Treatment for Vitreous Floaters

OBJECTIVE

To assess the quality, content, and readability of information available online on vitreous floater information.

DESIGN

Cross-sectional study.

PARTICIPANTS

Not applicable.

METHODS

Websites were generated using a Google search of "vitreous floaters treatment" and "[State]" and were analyzed using a standardized checklist of 22 questions. Readability was assessed using the Flesch Reading Ease score. Websites met qualification criteria if they represented U.S.-based institutions, if they provided clinical care and addressed vitreous floater treatment on their website.

RESULTS

Of the 1,065 websites screened, 456 were included. Of these, 406 (89%) were private institutions, 24 (5.3%) were academic, and 26 (5.7%) were a combination of private and academic. The average readability score correlated to a 10th-12th grade reading level. Vitreous floater treatment was discussed on 283 (62.1%) websites and 63 (21.8%) websites discussed potential side effects. Google rank was inversely correlated with the depth of explanation (r = -0.114, p = .016). Observation was the main treatment recommended (55.8%, n = 158), followed by laser treatment (27.6%, n = 78), no specific treatment recommendation (11.3%, n = 32), and vitrectomy (5.3%, n = 15). Centers with vitreoretinal surgeons were 16.43 times more likely to recommend vitrectomy than those without vitreoretinal surgeons (p < .001).

CONCLUSIONS

Online information about vitreous floater treatment is variable, and the material is at a higher than recommended reading level for health information. While treatment was discussed by nearly two thirds of websites, less than a quarter mentioned possible complications, and treatment recommendations varied significantly depending on physician training.

[Vitreous floaters]

Degenerative vitreous opacities (also known as myodesopsia) can cause permanent and relevant visual impairment. Neodymium-YAG laser vitreolysis is an alternative treatment option to pars plana vitrectomy for the treatment of disturbing degenerative vitreous opacities. This article critically discusses the different causes of vitreous opacities, the symptoms and functional impairments as well as clinical patient management. The aim is to support patient-oriented care and counselling of patients with vitreous opacities.

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.

[Evaluation of YAG-laser vitreolysis effectiveness based on quantitative characterization of vitreous floaters]

PURPOSE

To develop methods for evaluating effectiveness of YAG-laser vitreolysis of vitreous floaters.

MATERIAL AND METHODS

The study included 144 patients (173 eyes) who had underwent YAG-laser vitreolysis and were under observation from 01.09.16 to 31.01.18. The patients were 34 to 86 years old (mean age 62.7±10.2 years), 28 (19.4%) patients were male, 116 (80.6%) - female. All patients underwent standard and additional examination: ultrasonography (Accutome B-scan plus, U.S.A.), optic biometry (Lenstar 900, Haag-Streit, Switzerland), spectral optical coherence tomography using RTVue XR Avanti scanner (Optovue, U.S.A.) in modes Enhanced HD Line, 3D Retina, 3D Widefield MCT, Cross Line, Angio Retina, and scanning laser ophthalmoscopy (SLO) using Navilas 577s system. Laser vitreolysis was performed using the Ultra Q Reflex laser (Ellex, Australia).

RESULTS

This paper presents methods of objective quantitative and qualitative assessment of artifactual shadows of vitreous floaters with spectral optical coherence tomographic scanner RTVue xR Avanti employing an algorithm of automatic detection of non-perfusion zones in modes Angio Retina, HD Angio Retina, as well as foveal avascular zone (FAZ) measurement with Angio Analytics® software. SLO performed with Navilas 577s was used as method of visualizing floaters and artifactual shadows in retinal surface layers prior to surgical treatment and after YAG-laser vitreolysis.

CONCLUSION

Suggested methods of quantitative and qualitative assessment of artifactual shadows of the floaters in retinal layers are promising and may prove to be highly relevant for clinical monitoring of patients, optimization of treatment indications and evaluating effectiveness of YAG-laser vitreolysis. Further research of laser vitreolysis effectiveness in patients with vitreous floaters is necessary.

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.

Persistent troublesome floaters necessitating the explantation of XtraFocus Pinhole IOL (Morcher)

A 41-year-old patient presented with blurred vision and photophobia in the left eye with an uncorrected visual acuity of 20/150, improving to 20/30 with pinhole and diagnostic rigid gas permeable lens trial. He had a history of trauma with subsequent cataract extraction with residual irregular astigmatism and traumatic mydriasis. XtraFocus Pinhole intraocular lens (Morcher) was implanted in the left eye and the vision improved to 20/40. Postoperatively, the patient experienced significant floaters which persisted to the extent of necessitating explantation of implant.

Molecular Mechanisms Mediating Diabetic Retinal Neurodegeneration: Potential Research Avenues and Therapeutic Targets

Diabetic retinopathy (DR) is a devastating complication of diabetes with a prevalence rate of 35%, and no effective treatment options. Since the most visible clinical features of DR are microvascular irregularities, therapeutic interventions often attempt to reduce microvascular injury, but only after permanent retinal damage has ensued. However, recent data suggests that diabetes initially affects retinal neurons, leading to neurodegeneration as an early occurrence in DR, before onset of the more noticeable vascular abnormalities. In this review, we delineate the sequence of initiating events leading to retinal degeneration in DR, considering neuronal dysfunction as a primary event. Key molecular mechanisms and potential biomarkers associated with retinal neuronal degeneration in diabetes are discussed. In addition to glial reactivity and inflammation in the diabetic retina, the contribution of neurotrophic factors, cell adhesion molecules, apoptosis markers, and G protein signaling to neurodegenerative pathways warrants further investigation. These studies could complement recent developments in innovative treatment strategies for diabetic retinopathy, such as targeting retinal neuroprotection, promoting neuronal regeneration, and attempts to re-program other retinal cell types into functional neurons. Indeed, several ongoing clinical trials are currently attempting treatment of retinal neurodegeneration by means of such novel therapeutic avenues. The aim of this article is to highlight the crucial role of neurodegeneration in early retinopathy progression, and to review the molecular basis of neuronal dysfunction as a first step toward developing early therapeutic interventions that can prevent permanent retinal damage in diabetes. ClinicalTrials.gov: NCT02471651, NCT01492400.

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.

Surgical Outcomes of 27-Gauge Pars PLana Vitrectomy for Symptomatic Vitreous Floaters

Purpose

To report the surgical outcomes of 27-gauge pars plana vitrectomy (PPV) for symptomatic vitreous floaters.

Methods

47 eyes of 47 patients (39 males, 83.0%) with symptomatic vitreous floaters who underwent 27-gauge PPV and followed up for more than 6 months were included. The mean age was 34.7 ± 13.5 years.

Results

No operative complication occurred. At first day postoperatively, the intraocular pressure (IOP) was significantly lower than that at other time points (8.6 ± 2.7 mmHg, p < 0.001). 28 (59.6%) eyes had transient hypotony (IOP < 8 mmHg). All were recovered within 1 week postoperatively. The BCVA of 41 eyes (41/47, 87.2%) remained unchanged or improved. Postoperative complications occurred in two eyes: one (2.1%) had endophthalmitis and one (2.1%) had retinal detachment. No clinical significant cataract was observed in the 42 postoperative phakic eyes. 91.5% of the patients were satisfied with the surgery outcome. Besides, 91.3% of the patients felt that the floaters were removed completely or only had an acceptable residual.

Conclusion

Visual acuity of most patients remained unchanged or improved following 27-gague pars plana vitrectomy for symptomatic vitreous floaters, resulting in high patient satisfaction. However, this treatment should be performed with great caution since severe postoperative complications may still occur. This trial is registered with NCT03049163.

Many Faces of Renin-angiotensin System - Focus on Eye

The renin-angiotensin system (RAS), that is known for its role in the regulation of blood pressure as well as in fluid and electrolyte homeostasis, comprises dozens of angiotensin peptides and peptidases and at least six receptors. Six central components constitute the two main axes of the RAS cascade. Angiotensin (1-7), an angiotensin converting enzyme 2 and Mas receptor axis (ACE2-Ang(1-7)-MasR) counterbalances the harmful effects of the angiotensin II, angiotensin converting enzyme 1 and angiotensin II type 1 receptor axis (ACE1-AngII-AT1R) Whereas systemic RAS is an important factor in blood pressure regulation, tissue-specific regulatory system, responsible for long term regional changes, that has been found in various organs. In other words, RAS is not only endocrine but also complicated autocrine system. The human eye has its own intraocular RAS that is present e.g. in the structures involved in aqueous humor dynamics. Local RAS may thus be a target in the development of new anti-glaucomatous drugs. In this review, we first describe the systemic RAS cascade and then the local ocular RAS especially in the anterior part of the eye.

miRNAs in the vitreous humor of patients affected by idiopathic epiretinal membrane and macular hole

Purpose

The aim of the present study was to assess the expression of miRNAs in the Vitreous Humor (VH) of patients with Macular Hole (MH) and Epiretinal Membrane (ERM) compared to a control group.

Methods

In this prospective, comparative study, 2-ml of VH was extracted from the core of the vitreous chamber in consecutive patients who underwent standard vitrectomy for ERM and MH. RNA was extracted and TaqMan^® Low Density Arrays (TLDAs) were used to profile the transcriptome of 754 miRNAs. Results were validated by single TaqMan^® assays. Finally, we created a biological network of differentially expressed miRNA targets and their nearest neighbors.

Results

Overall 10 eyes with MH, 16 eyes with idiopathic ERM and 6 controls were enrolled in the study. Profiling data identified 5 miRNAs differentially expressed in patients affected by MH and ERM with respect to controls. Four were downregulated (miR-19b, miR-24, miR-155, miR-451) and 1 was downregulated (miR-29a); TaqMan^® assays of the VH of patients affected by MH and ERM, with respect to controls, showed that the most differentially expressed were miR-19b (FC -9.13, p:<0.00004), mir-24 (FC -7.52, p:<0.004) and miR-142-3p (FC -5.32, p:<0.011). Our network data showed that deregulation of differentially expressed miRNAs induces an alteration of several pathways associated with genes involved in both MH and ERM.

Conclusion

The present study suggests that disregulation of miR-19b, miR-24 and miR-142-3p, might be related to the alterations that characterize patients affected by MH and ERM.

27-Gauge Vitrectomy for Symptomatic Vitreous Floaters with Topical Anesthesia

Purpose

Traditionally acceptable methods of anesthesia for vitrectomy surgery are quite varied. However, each of these methods has its own potential for complications that can range from minor to severe. The surgery procedure of vitrectomy for symptomatic vitreous floaters is much simpler, mainly reflecting in the nonuse of sclera indentation, photocoagulation, and the apparently short surgery duration. The use of 27-gauge cannulae makes the puncture of the sclera minimally invasive. Hence, retrobulbar anesthesia, due to its rare but severe complications, seemed excessive for this kind of surgery.

Method

Three cases of 27-gauge, sutureless pars plana vitrectomy for symptomatic vitreous floaters with topical anesthesia are reported.

Results

The vitrectomy surgeries were successfully performed with topical anesthesia (proparacaine, 0.5%) without operative or postoperative complications. Furthermore, none of the patients experienced apparent pain during or after the surgery.

Conclusion

Topical anesthesia can be considered for 27-guage vitrectomy in patients with symptomatic vitreous floaters.

Moving Past Anti-VEGF: Novel Therapies for Treating Diabetic Retinopathy

Diabetic retinopathy is the leading cause of blindness in working age adults, and is projected to be a significant future health concern due to the rising incidence of diabetes. The recent advent of anti-vascular endothelial growth factor (VEGF) antibodies has revolutionized the treatment of diabetic retinopathy but a significant subset of patients fail to respond to treatment. Accumulating evidence indicates that inflammatory cytokines and chemokines other than VEGF may contribute to the disease process. The current review examines the presence of non-VEGF cytokines in the eyes of patients with diabetic retinopathy and highlights mechanistic pathways in relevant animal models. Finally, novel drug targets including components of the kinin-kallikrein system and emerging treatments such as anti-HPTP (human protein tyrosine phosphatase) β antibodies are discussed. Recognition of non-VEGF contributions to disease pathogenesis may lead to novel therapeutics to enhance existing treatments for patients who do not respond to anti-VEGF therapies.