A novel approach for 25-gauge transconjunctival sutureless vitrectomy to evaluate vitreous substitutes in rabbits.

AIM: To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits. METHODS: Three ports were prepared near the third eyelid of rabbits, and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter. All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution, silicone oil, and eight-arm polyethylene glycols (8-arm PEGs) hydrogel separately for comparison. Ophthalmic examinations were performed regularly to record the changes after the surgery. RESULTS: Successful vitrectomy was achieved among 44 chinchilla rabbits. The mean operation time was 4.51±1.25min. Four eyes (9.1%) presented limited lens touch and two eyes (4.5%) showed retinal touch during surgery. Incision leakage was found in three eyes (6.8%) after surgery. There was no endophthalmitis, hemorrhage, or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes. CONCLUSION: The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality.

Efficacy and safety of the dexamethasone implant in vitrectomized and nonvitrectomized eyes with diabetic macular edema: A systematic review and meta-analysis.

Purpose: To compare the efficacy and safety of the intravitreal dexamethasone (DEX) implant for the treatment of diabetic macular edema (DME) in vitrectomized and nonvitrectomized eyes. Methods: We performed a literature search in four electronic databases (PubMed, EMBASE, MEDLINE, and Cochrane Library) from inception to 22 May 2022. Studies comparing the efficacy of the DEX implant in vitrectomized and nonvitrectomized eyes with DME with at least 3 months of follow-up were included. The main outcomes included comparison of the mean change in the best-corrected visual acuity (BCVA) and central macular thickness (CMT) from baseline to different follow-up endpoints between the vitrectomized and nonvitrectomized groups. The secondary outcomes were the mean duration of action for the first DEX implantation and the number of required injections throughout the follow-up period. Safety data were collected and compared. Results: The final analysis included 7 studies involving 582 eyes, 208 vitrectomized eyes and 374 nonvitrectomized eyes. The mean between-group differences in BCVA improvement were not significant at any endpoint, with averages difference of -0.07 logarithm of the minimum angle of resolution (logMAR) (p = 0.088) at 1 month, -0.03 logMAR (p = 0.472) 3 months, -0.07 logMAR (p = 0.066) 6 months, and -0.04 logMAR (p = 0.486) 12 months. The mean between-group differences in CMT reduction were not statistically significant, with mean differences of 7.17 µm (p = 0.685) at 1 month, 20.03 µm (p = 0.632) 3 months, -1.80 µm (p = 0.935) 6 months, and -25.65 µm (p = 0.542) 12 months. However, the vitrectomized group had a significantly shorter duration of action during the first DEX implantation than the nonvitrectomized group, with a mean difference of 0.8 months (p = 0.005). No significant between-group differences were detected for the number of required injections or safety profile. Conclusion: This meta-analysis showed similar efficacy and safety of the sustained-release DEX intravitreal implant for vitrectomized and nonvitrectomized eyes with DME. The intravitreal DEX implant could be considered an effective choice for DME treatment in eyes with prior vitrectomy.

Comparative Study of Conventional Inverted ILM Flap Covering and ILM Flap Filling Technique in Idiopathic Macular Hole Treatment: A Meta-Analysis and Systematic Review.

Objective: This meta-analysis was performed to evaluate the anatomical efficacy and functional improvement of the conventional inverted internal limiting membrane (ILM), flap covering technique, and ILM flap filling technique for patients with idiopathic macular hole (MH). Methods: Literature from Pubmed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science were comprehensively retrieved. The primary outcomes included the MH closure rate and postoperative best-corrected visual acuity (BCVA). The secondary outcomes were the proportion of external limiting membrane (ELM) and ellipsoid zone (EZ) defect recovery. Pooled odds ratios (ORs), weighted mean differences (WMDs), and 95% confidence intervals (CIs) were calculated using STATA 17.0 software. Results: 7 studies that contained 139 eyes in the inverted ILM flap covering group and 121 eyes in the ILM flap filling group were selected. Pooled data suggested that the surgical treatment resulted in an overall MH closure rate of up to 97.12% (135/139 eyes) in the inverted ILM flap covering group and 99.17% (120/121 eyes) in the filling group, with no significant difference between the 2 groups (OR = 1.98, 95% CI: 0.55 to 7.09, and P=0.29). Similarly, the 2 techniques demonstrated equal effectiveness on the anatomical closure in MH with the average diameter smaller than 650 µm (OR = 2.17, 95% CI: 0.48 to 9.77, and P=0.31) and larger than 650 µm (OR = 1.58, 95% CI: 0.14 to 17.37, and P=0.71). However, compared with the filling technique, the inverted ILM flap covering technique was superior in postoperative BCVA (WMD = 0.11, 95% CI: 0.04 to 0.18, and P=0.0017) and presented a significantly higher proportion of reconstitution of ELM (OR = 0.02, 95% CI: 0.00 to 0.08, and P < 0.0001) and EZ (OR = 0.11, 95% CI: 0.04 to 0.32, and P=0.0001). Conclusion: The inverted ILM flap covering technique was associated with the superior reconstitution of outer layers of the retina, including ELM and EZ, and more improvement in postoperative BCVA than the ILM flap filling technique.

Outcomes of the flanged intrascleral haptic fixation with double-needle technique in patients with Marfan syndrome.

PURPOSE: To investigate the clinical outcomes and complications associated with the flanged intrascleral haptic fixation with double-needle technique (a.k.a. the Yamane technique/FIHFT) in patients with Marfan syndrome (MFS) with subluxated or dislocated lenses. METHODS: Eighteen eyes of 11 patients with MFS with subluxated or dislocated lenses who had undergone intraocular lens implantation using the FIHFT from March 2019 to October 2020 were evaluated. All patient data were retrospectively collected from medical records, including a complete ophthalmologic examination at baseline and follow-up examinations of uncorrected visual acuity (UCVA, logMAR), best-corrected visual acuity (BCVA, logMAR), intraocular pressure (IOP), and slit-lamp examination. RESULTS: The median follow-up period was 6 ± 3 (range, 3-12) months. The average patient age at the time of surgery was 13 ± 9 (range, 4-34) years. The mean preoperative BCVA was 0.49 ± 0.20 logMAR (Snellen equivalent visual acuity, 20/60), while the mean postoperative BCVA at the end of follow-up was 0.21 ± 0.14 logMAR (20/30), indicating an improvement of 0.28 ± 0.20 logMAR (20/40) postoperatively (p < 0.001). Postoperative iris capture occurred in six eyes (38.9%). No cases of hypotony, IOP elevation, or vitreous hemorrhage were noted, and no patients developed intraocular lens dislocation, retinal detachment, or endophthalmitis. CONCLUSIONS: To our knowledge, the present study is the first to report outcomes of the FIHFT in patients with MFS. Our findings suggested that scleral lens fixation is safe and effective for improving visual acuity in patients with MFS who have subluxated or dislocated lenses.

Efficacy and safety of single-dose dexamethasone implantation for patients with persistent diabetic macular edema: a systematic review and meta-analysis.

PURPOSE: This meta-analysis was conducted to evaluate the efficacy and safety of single-dose dexamethasone implantation for treating persistent DME (diabetic macular edema) refractory to anti-VEGF (anti-vascular endothelial growth factor) drugs over a period of 6 months. METHODS: All related clinical trials were reviewed by searching electronic databases of PubMed, Medline, Web of Science, Cochrane Library, and EMBASE. The primary outcome parameters were best-corrected visual acuity (BCVA) and central macular thickness (CMT). We performed this meta-analysis by using Stata15.0. RESULTS: Ten clinical trials involving 362 eyes from 328 patients were eligible in the final analysis. After single-dose dexamethasone implantation, there was a significant improvement in BCVA from baseline to 1, 3, and 6 months with an average increase of - 0.15 logMAR (p < 0.001), - 0.14 logMAR (p < 0.001), and - 0.07 logMAR (p = 0.004), respectively. Further, mean CMT decreased significantly with an average reduction of 249.18 µm (p < 0.001), 217.66 µm (p < 0.001), and 91.56 µm (p < 0.001) at months 1, 3, and 6, respectively. CONCLUSIONS: Our results indicate that switching to a dexamethasone implant could achieve significant anatomical and functional improvement among patients with refractory DME. Clinicians should be aware of this treatment option in refractory DME.