Safety and Efficacy of YAG Laser Vitreolysis for the Treatment of Vitreous Floaters: An Overview

Forward Light Scattering of the Vitreous Gel After Enzymatic Aging: An In Vitro Model to Study Vitreous Opacification

Purpose

Symptomatic vitreous opacifications, so-called floaters, are difficult to objectively assess majorly limiting the possibility of in vitro studies. Forward light scattering was found previously to be increased in eyes with symptomatic floaters. Using an objective setup to measure forward light scattering, we studied the effects of enzymatically digesting the components of the vitreous body on straylight to develop an in vitro model of vitreous opacifications.

Methods

Fifty-seven porcine vitreous bodies were digested using hyaluronidase, collagenase, trypsin, and bromelain, as well as using a combination of hyaluronidase + collagenase and hyaluronidase + bromelain. A modified C-Quant setup was used to objectively assess forward light scattering.

Results

Depletion of hyaluronic acid majorly increased vitreous straylight (mean increase 34.4 deg2/sr; P = 0.01), whereas primarily digesting the vitreous gel with collagenase or trypsin did not significantly affect straylight. When collagenase or bromelain is applied in hyaluronic acid depleted vitreous gels, the increase in forward light scattering is reversed partially.

Conclusions

The age-related loss of hyaluronic acid primarily drives the increase in vitreous gel straylight induced by conglomerates of collagen. This process can be reversed partially by digesting collagen. This in vitro model allows the objective quantification and statistical comparison of straylight burden caused by vitreous opacities and, thus, can serve as a first testing ground for pharmacological therapies, as demonstrated with bromelain.

Efficacy and safety of early YAG laser vitreolysis for symptomatic vitreous floaters: the study protocol for a randomized clinical trial

BACKGROUND

Vitreous floaters are a common ocular condition that affects individuals of all ages. Although vitreous floaters are typically benign, they can significantly impair visual acuity and quality of life. Laser vitreolysis, which uses an Nd: YAG laser to vaporize collagenous vitreous opacities, is increasingly being used as a treatment option. However, there is currently a lack of evidence regarding its efficacy and the appropriate timing of its application. This study aims to evaluate the efficacy and safety of early intervention with YAG laser vitreolysis in treating symptomatic vitreous floaters.

METHODS

The present study is a randomized, controlled, double-blind clinical trial. A total of 70 participants with symptomatic floaters for 1 month were prospectively recruited. These participants will be randomly assigned to two groups, with 35 individuals in each group: the early treatment group and the delayed treatment group. Participants assigned to the early treatment group will undergo YAG laser vitreolysis immediately, followed by a sham laser treatment 3 months later. On the other hand, participants assigned to the delayed treatment group will receive a sham laser treatment and then undergo YAG laser vitreolysis 3 months later. The follow-up time points will be 1, 3, 6, and 12 months from randomization. Primary outcomes will be participants' self-reported improvement in visual disturbance on a scale of 1 to 10 and their scores on the National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25). Secondary outcomes will be an objective evaluation of the effectiveness of the treatment in reducing vitreous floaters through OCT and fundus photography and tracking any adverse events related to the eyes or overall health.

DISCUSSION

This clinical trial aims to evaluate the effectiveness of YAG laser vitreolysis in treating symptomatic vitreous floaters and assess the safety of performing early intervention with YAG laser vitreolysis.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05800353 . Registered on 10 March 2023.

Safety of YAG laser vitreolysis for intraocular tissues: analysis of postoperative complications

PURPOSE

To evaluate the safety of yttrium-aluminum-garnet (YAG) laser vitreolysis for intraocular tissues.

METHODS

Thirty-six New Zealand rabbits were divided as follows: Group 1000 (n = 12) treated with YAG laser of 1000 mJ (5 mJ × 200 shots), Group 2000 (n = 12) treated with YAG laser of 2000 mJ (5 mJ × 400 shots), Group 3000 (n = 12) treated with YAG laser of 3000 mJ (5 mJ × 600 shots). Either a single eye was chosen as the study eye in study groups while the other was untreated as the control group. Intraocular pressure (IOP), slit-lamp, optical coherence tomography (OCT), transmission electron microscopy (TEM), and inflammatory cytokines of aqueous humor (interleukin-1α (IL-1α), interleukin-1β (IL-1β), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α)) were performed to examine the rabbits.

RESULTS

There were no abnormalities in the study groups of IOP, slit-lamp, and OCT examinations. Group 3000 of TEM showed: neutrophils and mitochondrial swelling on day 1, and fibroblasts and neocollagen on day 14. No abnormalities were observed in Group 1000 and 2000 of TEM. Levels of IL-1α and TNF-α increased at 12 h and decreased to baseline on day 3. Levels of IL-1β increased at 12 h and decreased to baseline on day 7. Levels of IL-8 increased on day 1 and decreased to baseline on day 3.

CONCLUSION

YAG laser vitreolysis is safe when the distance is more than 2 mm from ablation point to the lens and the retina, and the total energy is less than 2000 mJ for one treatment procedure.

Long-term efficacy and safety of YAG laser vitreolysis for vision degrading myodesopsia

AIM

To assess the long-term efficacy and safety of yttrium-aluminum garnet (YAG) laser vitreolysis for vision degrading myodesopsia (VDM) caused by posterior vitreous detachment (PVD).

METHODS

This retrospective study reviewed VDM patients of PVD type undergoing YAG laser vitreolysis. The baseline demographic information, the patterns of floaters, the number of floaters, and the subjective improvement of floater sympotoms (ranging from 0 to 100%) from medical records were collected. Significant improvement was defined as a relief of floater symptoms of ≥50% at the final visit. The long-term efficacy and safety of YAG laser vitreolysis were analyzed. The risk factors linked to significant improvement of floater symptoms were defined using univariate and multivariate logistic regression analyses.

RESULTS

The final analysis included 221 patients with VDM. The mean age of patients was 61.08±7.74y, and the mean length of follow-up was 21.38±5.61mo. Totally 57.01% of patients experienced a significant improvement in their floater symptoms after YAG laser therapy, and none of them developed delayed retinal abnormalities such as retinal tears or detachments. Age (OR=1.049, 95%CI=1.007-1.092, P=0.021) was identified as a significant risk factor for significant improvement in VDM.

CONCLUSION

YAG laser vitreolysis is an effective and secure treatment for PVD-type VDM, and patients of advanced age are more likely to get favorable outcomes.

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.

Design of a Functional Eye Dressing for Treatment of the Vitreous Floater

With the rapid development of display technology, related diseases of the human eye are also increasing day by day. Eye floaters are one of the diseases that affect humans. Herein, we present a functional ophthalmic dressing that can permeate the skin tissues of the eyes through oxygen and hydrogen to improve the symptoms of floaters. In clinical tests, the symptoms of sensory floaters improved in 28 patients, and the recovery rates of mild, moderate, and severe floaters were about 70%, 66.7%, and 83.3%, respectively.

Efficacy Evaluation of the VFQ-25 Scale in Patients with Different Degrees of Vitreous Opacity After Nd : YAG Laser Ablation

Objective

To evaluate the effect of the VFQ-25 scale on the efficacy of Nd : YAG laser ablation in patients with different severity of vitreous opacities.

Methods

From January 2020 to March 2021, data of patients who presented to our department and were diagnosed with vitreous opacity were collected, and the severity of vitreous opacity was divided into four grades: I, II, III, and IV. Preoperative visual acuity, intraocular pressure, dilated fundus, B ultrasound, and other examinations were performed, and the patients were scored using the VFQ-25 scale. All patients underwent Nd : YAG laser ablation and were followed for 6 months. The VFQ-25 scale was again used postoperatively to score the patient's efficacy. The general information and clinical characteristics of the patients we collected. The Spearman's test was used to evaluate the correlation between VFQ-25 score and Nd : YAG laser efficacy in patients.

Results

A total of 80 patients (95 eyes) were included in this study. Vitreous opacities were grade I in 56 eyes (58.9%), grade II in 22 eyes (23.2%), grade III in 10 eyes (10.5%), and grade IV in 7 eyes (7.4%). Compared with preoperative scores, patients with vitreous opacity had significantly higher postoperative scores in terms of overall health (36.54 ± 17.06 vs 33.52 ± 16.74), overall visual acuity (60.39 ± 14.24 vs 57.56 ± 13.13), color vision (88.94 ± 12.56 vs 86.38 ± 12.37), and peripheral visual acuity (74.06 ± 18.38 vs 72.20 ± 18.79) items (all P < 0.001). The overall response rates of vitreous opacities I, II, III, and IV were 100%, 90.9%, 80.0%, and 71.4%, respectively. There was a significant correlation between the postoperative VFQ-25 total score, and the therapeutic effect of laser ablation for grade I vitreous opacities, with a correlation coefficient r of 0.417 (P=0.001). The correlation coefficient r between the total score of postoperative VFQ-25 and the treatment effect of grade II vitreous opacity was 0.622 (P=0.002). However, the correlation between the postoperative efficacy of grade III and IV patients and the VFQ-25 score was not significant.

Conclusion

In patients with different degrees of vitreous opacity undergoing Nd : YAG laser vitreous ablation, the overall health, overall visual acuity, color vision, and peripheral visual acuity were improved after surgery, and the VFQ-25 score was significantly correlated with the postoperative efficacy, which is worthy of clinical use.

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.

Trabeculopuncture as a predictive test of distal outflow resistance in canal-based surgery

We investigated whether trabeculopuncture (TP) could detect distal outflow resistance to predict the outcome of canal-based glaucoma surgery such as ab interno trabeculectomy (AIT). These procedures have a high utilization in open angle glaucoma, but fail in eyes with an unidentified distal outflow resistance. We assigned 81 porcine eyes to two groups: trial (n = 42) and control (n = 39). At 24 h, four YAG-laser trabeculopunctures were placed nasally, followed by a 180° AIT at the same site at 48 h. The proportion of TP responders between both AIT groups was compared. Histology and outflow canalograms were determined. Both post-TP and post-AIT IOPs were lower than baseline IOP (p = 0.015 and p < 0.01, respectively). The success rates of TP and AIT were 69% and 85.7%, respectively. Sensitivity and specificity values of TP as predictive test for AIT success were 77.7% and 83.3%, respectively. The positive and negative predictive values were 96.6% and 38.5%, respectively. We conclude that a 10% reduction in IOP after TP can be used as a predictor for the success (> 20% IOP decrease) of 180° AIT in porcine eyes.

Secondary open-angle glaucoma following YAG-laser vitreolysis

We report a case of a man in his 50s who developed open-angle glaucoma following neodymium-doped yttrium aluminium garnet (YAG) laser vitreolysis. Despite attempts to control the pressure with topical medication and selective laser trabeculoplasty (SLT), surgical intervention using a Baerveldt glaucoma valve (BGV) was needed after which the intraocular pressure was controlled successfully. This rare but serious complication highlights the fact that in certain cases long-term monitoring of intraocular pressure is necessary following laser vitreolysis.

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.

Retinal Complications after Yttrium-Aluminum-Garnet Laser Vitreolysis for Vitreous Floaters

This is an observational case series of two patients who developed direct retinal damage following neodymium-doped yttrium-aluminum-garnet (YAG) laser treatment for symptomatic vitreous floaters. The first patient developed a vitreous hemorrhage and subsequent branch retinal vein occlusion from laser damage to a major retinal venule. The second patient developed a temporal scotoma from a full-thickness retinal break in the posterior pole requiring laser retinopexy. Direct YAG laser damage to the posterior pole can cause permanent visual deficits. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:610-613.].

Vitreous function and intervention of it with vitrectomy and other modalities

The vitreous body, the largest intraocular component, plays a key role in eye development, refraction, cell barrier function, oxygen metabolism and the pathogenesis of assorted diseases. Age, refraction and systemic diseases can cause vitreous metabolic abnormalities. With the continuous development of vitrectomy techniques and equipment, vitreous injections and vitrectomies have increased over the recent decades. However, the normal oxygen tension gradient in the vitreous helps to protect the lens and anterior chamber angle from oxidative stress damage, whereas the increased vitreous oxygen tension around lens and the trabecular meshwork after vitrectomy may lead to postoperative nuclear cataract and a high incidence of open angle glaucoma. As a conventional procedure, scleral buckling holds several advantages over vitrectomy in selected cases. This review raises concerns regarding the function of the vitreous, and encourages conducting vitreous interventions prudently.

Nd:YAG laser vitreolysis and health-related quality of life in patients with symptomatic vitreous floaters

BACKGROUND

The treatment of floaters has consisted primarily of monitoring. The therapeutic approach is based on surgical removal or Nd:YAG laser treatment. The objective of this study was the assessment of the quality of life in patients treated with Nd:YAG laser for floaters.

METHODS

Single-center pretest-posttest design in a cohort of subjects treated with Nd-YAG laser with Ultra Q-Reflex technology. Health-related quality of life of the patients was measured before and after the intervention with the Visual Function Questionnaires VFQ-25 and VFQ-39. Anxiety level was measured with the State-Trait Anxiety Inventory. Visual acuity, contrast sensitivity, and safety parameters were also considered.

RESULTS

Thirty-four patients were included in the study. For the VFQ-25 baseline, the median was 73.05, interquartile range (19.25) versus a final median value of 93.76 (8.73) with p < 0.01. The baseline median for the extended version VFQ-39 was 74.60 (19.01) versus the final median of 95.01 (6.50) with p < 0.001. Regarding the anxiety, according to the STAI questionnaire, there were statistically significant differences between the baseline and the final conditions, with a baseline median of 38 (11) versus a final median of 18 (19); p < 0.001. When the analyses differentiated between patients with and without myopia, there were statistically significant differences for VFQ-25 and VFQ-39.

CONCLUSIONS

This study shows an improvement in the health-related quality of life and a significant decrease in anxiety for patients that have undergone Nd: YAG Ultra-Q Reflex laser vitreolysis for floaters vaporization. The effect found is higher in myopic patients.