The effect of irrigation and aspiration on the corneal endothelial cell density in patients undergoing Implantable Collamer Lens with a central hole implantation for myopia correction.

PURPOSE: In the conventional technique, viscoelastic agents are typically rinsed away with balanced salt solution (BSS), but it may lead to a series of complications such as viscoelastic residue, anterior chamber instability and intraoperative TICL rotation. The utilization of irrigation and aspiration (I/A) has been shown to be effective in maintaining anterior chamber stability, reducing the incidence of postoperative high intraocular pressure, and minimizing postoperative fundus complications. However, there is a lack of previous studies investigating the impact of I/A on corneal endothelial cells during ICL implantation. The objective of this study was to examine the effect of I/A on corneal endothelial cells in patients undergoing myopia correction through implantation of Implantable Collamer Lens with a central hole (V4c ICL). METHODS: A retrospective selection was made of 344 eyes from 172 patients who underwent V4c ICL implantation and I/A to remove viscoelastic agent from the anterior chamber between 2021 and 2022. The intraocular pressure (IOP) was measured at 1 h, 2 h and 3 h after surgery. Corneal endothelial cell density (ECD), coefficient of variation in cell size (CV), standard deviation of cell area (SD), and percentage of hexagonal cells (HEX) were evaluated at 1 week postoperatively to assess corneal endothelial cells. The first two represent polymegethism or morphological variation, while the third parameter represents the degree of polymorphism of the corneal endothelial cells. Electronic medical records were utilized for data collection purpose. RESULTS: All surgeries proceeded without complications. The IOP was 16.50 ± 3.42 mmHg (range: 11.5-22.3 mmHg) prior to surgery and increased to 21.25 ± 5.61 mmHg (range: 9.5-34.8 mmHg), 19.85 ± 5.18 mmHg (range: 11.4-36.2 mmHg) and finally settled at an average of 18.81 ± 4.57 mmHg (range: 10.1-38.8 mmHg) at the respective time points of 1 h, 2 h and 3 h after surgery. The preoperative ECD was recorded as being approximately 3004 ± 295 cell/mm2, which exhibited a marginal decreased of 1.17% postoperatively, resulting in an average ECD value of 2969 ± 303 cell/mm2 one week after surgery (P = 0.12). Similarly, the preoperative CV was determined as 31.10 ± 3.78%, and it experienced a slight reduction with an average CV value of 30.74 ± 3.77% at week after surgery (P = 0.21). And, the preoperative SD was reported as 104.76 ± 17.26, and it remained virtually unchanged with an average SD value of 104.85 ± 18.75 at one week after surgery (P = 0.95). The preoperative HEX was calculated as 55.38 ± 8.94%, and it remained its stability with an average HEX value of 55.45 ± 8.73% one week after surgery (P = 0.92). CONCLUSION: The utilization of I/A led to a slight decrease in postoperative ECD when compared to conventional surgical techniques. Nevertheless, the reduction in ECD remained within acceptable limits, taking into accout the avervantaged it offered, such as stabilization of the anterior chamber and decreased occurrence of viscoelastic residue after surgery. It is challenging to anticipate the long-term safety of corneal endothelial cells based on current short-term studies. However, this study provides a valuable reference indicating that neither anterior chamber irrigation nor I/A aspiration have an adverse impact on the safety of corneal endothelial cells in the short term. Further research is imperative to enhance our understanding of their effects over an extended period.

Diluting 2.5% Viscoadaptive Sodium Hyaluronate to Prevent Postoperative Intraocular Pressure Rise After Phacoemulsification: A Pilot Study.

The most common complication with intraoperative viscoelastic use is an immediate elevation of intraocular pressure, particularly if the viscoelastic agent remains in the eye, which can cause serious effects. Complications may include severe ocular pain, corneal epithelial edema, and increased risk of anterior ischemic optic neuropathy and retinal artery occlusion. This study aims to find an efficient and safe adjunctive method to decrease the incidence of postoperative intraocular pressure rise. When cohesive viscoelastic agents were unavailable due to the pandemic, we diluted Microvisc 2.5% sodium hyaluronate ophthalmic viscosurgical device by 50% prior to intraocular lens implantation. Twelve eyes are included in this study, which are divided into two groups. The study followed a double-blinded methodology in which the physician and the patient were unaware of what group they were in. The first group (seven patients, seven eyes) was treated using the diluted Microvisc 2.5%, and the second group (five patients, five eyes) was controlled with the undiluted Microvisc 2.5%. The primary variable was intraocular pressure, measured at four different timeline points (baseline, day 1, week 1, and month 1). We found that the technique used had easier irrigation and aspiration with minimal viscoelastic agent left in the bag, leading to a lower postoperative intraocular pressure spike. Analysis was conducted using the Wilcoxon signed rank test, and significance was noted between the two groups on postoperative day 1 (p=0.042). The analysis also included the populations' comorbidities (hypertension and diabetes) and postoperative outcomes (pain, corneal edema, and visual acuity).

A pilot study of viscoelastic agent to prevent recurrent vitreous hemorrhage after vitrectomy for proliferative diabetic retinopathy.

BACKGROUND: To evaluate the possibilty of preventing recurrent vitreous hemorrhage (RVH) after vitrectomy in proliferative diabetic retinopathy (PDR) patients with unabsorbed vitreous hemorrhage (VH) by intravitreal injection of viscoelastic agent (VA) at the end of the surgery and compared its effect with triamcinolone acetonide (TA). METHODS: This was a pilot prospective, observational study. PDR patients with VH who underwent vitrectomy were assigned to 3 groups according to the tamponade applicated at the end of the surgery, including VA group (intravitreally injected 1 ml VA if the retina was prone to bleed during the operation), TA group (intravitreally injected 2 mg TA when there was much exudates), or balanced salt solution (BSS) group (no tamponade). Then postoperative follow-up was performed routinely until 6 months after surgery. The primary outcome was the incidence of RVH, secondary outcome were the best-corrected visual acuity (BCVA) and introcular pressure (IOP). Cataract formation and other complication were also assessed. RESULTS: A total of 68 eyes, from 68 patients, were included. 18,18,32 eyes were enrolled in the VA group, TA group and BSS group, respectively. The integral incidence of RVH after vitrectomy was 5.6%, 5.6% and 12.5% respectively (P = 0.602). There was no early RVH in VA or TA group, whereas 3 early RVHs were identified in BSS group, however there was no significant difference (P = 0.171). Every group had one late RVH case. In all groups, final BCVA showed significant improvement compared to baseline. BCVA at any postoperative visit showed no significant differences among 3 groups. Mean IOP was higher 1 week after surgery in VA group compared with the other groups; however, in other times the differences were not significant. No cataract formation and other complication was noted in 3 groups. CONCLUSION: Intravitreal injection of VA or TA at the end of vitrectomy for PDR patients with unabsorbed VH tend to reduce the incidence of early RVH after vitrectomy similarly. As VA was preferred to applicate in the eyes that were prone to bleed, intravitreal injection of VA at the end of vitrectomy might be a promising method for preventing RVH in PDR patients.

Implantation of intraocular lens without viscoelastic agent in phacoemulsification cataract surgery.

PURPOSE: To observe the clinical effect of implanting intraocular lens (IOL) without viscoelastic agent in phacoemulsification cataract surgery. METHODS: A retrospective analysis of 87 patients (87 eyes) with senile cataracts was performed. According to whether viscoelastic agents were injected before IOL implantation, they were divided into 2 groups. The endothelial cell density (ECD), intraocular pressure (IOP), uncorrected distance visual acuities (UDVA), and operation complications were evaluated preoperatively and postoperatively, and operation time was recorded. RESULTS: The experimental group (no viscoelastic group) contained 42 cases (42 eyes), and the control group (viscoelastic group) contained 45 cases (45 eyes). The operation time of the experimental group (7.261 ± 0.75 s) was significantly shorter than that of the control group (7.802 ± 1.14 s) (t = -2.629, P = 0.01). The IOP of the experimental group (16.71 ± 2.04 mmHg) was significantly lower than that of the control group (19.56 ± 8.98 mmHg) at 4 h after surgery (t = -2.065, P = 0.04). There was no statistically significant difference in UCDV, ECD between the two groups of patients (P > 0.05). There were no complications of intraoperative PCR in both groups. CONCLUSIONS: Implantation of IOL without viscoelastic agent can shorten the operation time and reduce the occurrence of high IOP in the early postoperative period.

One-step viscoelastic agent technique for ICL V4c implantation for myopia.

AIM: To investigate the safety and efficacy of using a one-step viscoelastic agent technique for posterior chamber phakic implantable collamer lens with a central hole (ICL V4c) implantation for myopia correction. METHODS: The one-step viscoelastic agent technique for ICL V4c implantation was used in 100 eyes of 52 patients. Refractive outcomes, intraocular pressure (IOP), corneal endothelial cell, and corneal densitometry values were evaluated at 1d, 1wk, 1 and 3mo postoperatively. RESULTS: All the surgeries were uneventful. No corrected distance visual acuity was lost after 3mo. IOP was 16.12±3.18 mm Hg before surgery, and 14.74±3.08 mm Hg at 1d and 14.50±2.56 mm Hg at 3mo after surgery (P<0.05). Corneal endothelial cell density was 2580±242 cell/mm2, the coefficient of variation in cell size was 42.11%±7.92%, and the percentage of hexagonal cells was 40.98%±9.46% before surgery. No significant difference was found when these outcomes were compared between the studied time points (P>0.05). The corneal densitometry values of the central 2 mm and 2 to 6 mm areas showed similar regularities. After surgery, the values significantly increased at 1d, then decreased to the preoperative values at 1wk, and then continued to decrease at 3mo (P<0.05). CONCLUSION: The one-step viscoelastic agent technique for ICL V4c implantation is found to be safe and effective for myopia correction and causes little disturbance to the cornea.

Comparison of anterior chamber maintainer and viscoelastic agent on corneal astigmatism and endothelial cells after phacoemulsification / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To compare the influence of anterior chamber maintainer and viscoelastic agent on corneal astigmatism and endothelial cells after phacoemulsification.METHODS:Totally 70 patients(70 eyes) of cataract from April 2013 to April 2015 were randomly divided into the study group and the control group, with 35 cases in each group.The study group were treated with anterior chamber maintainer during phacoemulsification with support system approach, and the control group were treated with phacoemulsification under viscoelastic agent.RESULTS:The age (t=0.215, P=0.831), the density of corneal endothelial cells (t=-0.352, P=0.726) and corneal luminosity (t=-0.162, P=0.872) of two groups had no significant difference before surgery;there were no significant difference in preoperative visual acuity (t=0.463, P=0.599) and visual acuity (t=1.616, P=0.124) at 1mo after operation.And patients in the study group (t=-21.129, P<0.01) and the control group (t=-12.780, P<0.01) before surgery and 1mo postoperative when compared with the naked eye eyesight showed significant difference.The visual acuity after operations improved significantly.There were significant differences of corneal endothelial cells density (t=8.489, P< 0.01) and corneal astigmatism (t=-2.032, P=0.046) in the study group before surgery and 1mo after surgery;corneal endothelial cell density (t=8.999, P<0.01) and corneal astigmatism (t=-2.167, P=0.034) in the control group before surgery and 1mo after surgery also had significant differences.There was no significant difference in the rate of corneal endothelial cell loss between the two groups (t=0.410, P=0.683).CONCLUSION:Compared with viscoelastic agent, anterior chamber maintainer during phacoemulsification in patients with cataract won't increase the damage of postoperative surgically induced astigmatism and corneal endothelial cells, which mean the method of anterior chamber maintainer during phacoemulsification in the treatment of cataract is safe and effective.

Principle and advantages of using viscoelastic agent undergo goniosynechialysis during glaucoma and cataract combined surgery / 国际眼科杂志(Guoji Yanke Zazhi)

To investigate the advantage of using the medical sodium hyaluronate gel undergo goniosynechialysis, and to compare the difference of the viscoelastic agent and perfusion fluid by clinical control study. ●METHODS:Totally 103 cases (103 eyes) patients who had angle- closure glaucoma (ACG) with cataract all in Beijing Tongren Hospital affiliated to Capital Medical University, from September 2012 to February 2013. All the patients had primary glaucoma or recurrence ACG with cataract. Their intraocular pressure (lOP) could be controlled in normal value using one or two anti -glaucoma medications. We divided all the patients into two groups by chance. Experimental group had 53 cases (50 eyes), and control group had 50 cases (53 eyes). Two groups all had been performed phacoemulsification combined with goniosynechialysis by the same experiential operator. But experimental group did goniosynechialysis using the medical sodium hyaluronate gel, control group did goniosynechialysis using perfusion fluid. We observed the change of lOP, central anterior chamber depth and anterior chamber structure of two groups in postoperative 1mo. ●RESULTS: SPSS19. 0 statistics software was utilized to analyze the data, This study selected one- side test α =0. 05, adopted paired t - test or two- sample t - test. We obtained that experimental group lOP decreased 12. 42 ± 0. 04mmHg, anterior chamber depth increased 1. 276 ± 0. 201mm; that control group lOP decreased 6. 56 ± 0. 08mmHg, anterior chamber depth increased 0. 852 ± 0. 132mm. And experimental group anterior chamber angle opened more widely than the other group, the comparison had statistical significance (P ●CONCLUSlON: ln phacoemulsification combine with goniosynechialysis,use medical sodium hyaluronate gel do goniosynechialysis can more effectively decrease lOP. This because the medical sodium hyaluronate gel has high glutinousness, it can separate angle of anterior chamber and controlling lOP effectively.

Commercially available rigid gas-permeable contact lens for protecting the cornea from drying during vitrectomy with a wide viewing system.

PURPOSE: We evaluated the usefulness of commercially available materials for protecting the cornea from drying during vitrectomy with a wide-angle viewing system. METHODS: THREE VITREORETINAL SURGEONS EVALUATED FUNDUS VISIBILITY DURING VITRECTOMY ON THE IMAGES OF FIVE STUDY MATERIALS USED ON THE CORNEA: balanced saline solution, a viscoelastic agent, a vitrectomy contact lens, a rigid gas permeable (RGP) contact lens, and a soft contact lens. Fundus visibility was graded using the following scale: grade 1, unclear; grade 2, slightly unclear; grade 3, clear; and grade 4, very clear. RESULTS: RESPECTIVE SCORES FOR EACH MATERIAL USED DURING CORE VITRECTOMY AND MEMBRANE REMOVAL WERE: balanced saline solution, 3.3/3.3; viscoelastic agent, 3.8/3.3; vitrectomy contact lens, 3.3/4.0; RGP contact lens, 4.0/3.9; soft contact lens, 1.1/not applicable. CONCLUSION: The RGP contact lens provided visibility similar to or clearer than that obtained with other methods. Because of its ease of use and lower cost, use of the RGP contact lens is ideal during vitrectomy performed with a wide-angle viewing system.

A clinical comparison between DisCoVisc and 2% hydroxypropylmethylcellulose in phacoemulsification: a fellow eye study

OBJECTIVE: This study sought to compare the effects and outcomes of two ophthalmic viscosurgical devices, 1.6% hyaluronic acid/4.0% chondroitin sulfate and 2.0% hydroxypropylmethylcellulose, during phacoemulsification. METHODS: This prospective, randomized clinical trial comprised 78 eyes (39 patients) that received phacoemulsification performed by the same surgeon using a standardized technique. Patients were randomly assigned to receive either 1.6% hyaluronic acid/4.0% chondroitin sulfate or 2.0% hydroxypropylmethylcellulose on the first eye. The other eye was treated later and received the other viscoelastic agent. Preoperative and postoperative examinations (5, 24 and 48 hours; 7 and 14 days; 3 and 6 months) included measurements of the total volume of the ophthalmic viscosurgical device, ultrasound and washout times to completely remove the ophthalmic viscosurgical device, intraocular pressure, central corneal thickness and best-corrected visual acuity. The corneal endothelial cell count was measured at baseline and at six months postoperatively. ClinicalTrials.gov: NCT01387620. RESULTS: There were no statistically significant differences between groups in terms of cataract density or ultrasound time. However, it took longer to remove 2.0% hydroxypropylmethylcellulose than 1.6% hyaluronic acid/ 4.0% chondroitin sulfate, and the amount of viscoelastic material used was greater in the 2.0% hydroxypropylmethylcellulose group. In addition, the best-corrected visual acuity was significantly better in the hyaluronic acid/ chondroitin sulfate group, but this preferable outcome was only observed at 24 hours after the operation. There were no statistically significant differences between the two ophthalmic viscosurgical devices regarding the central corneal thickness or intraocular pressure measurements at any point in time. The corneal endothelial cell count was significantly higher in the hyaluronic acid/chondroitin sulfate group. CONCLUSION: The ophthalmic viscosurgical device consisting of 1.6% hyaluronic acid/4.0% chondroitin sulfate was more efficient during phacoemulsification and was easier to remove after IOL implantation than 2.0% hydroxypropylmethylcellulose. In addition, the corneal endothelial cell count was significantly higher following the use of hyaluronic acid/chondroitin sulfate than with hydroxypropylmethylcellulose, which promoted an improved level of corneal endothelium protection.

Preparation of artificial viscoelastic agent / 中国康复理论与实践

@#ObjectiveTo prepare artificial viscoelastic agent used in ophthalmic operation as a substitute of Healon. MethodsPolyacrylamide was synthesized in aqueous solution of acrylamide. Residual monomer(Am) was separated from polymer by a novel method, extraction by semi permeable film. Results and ConclusionsArtificial viscoelastic agent prepared has advantages on cost of manufacture, processing repeatability and stability of storage comparing to Healon.