Transconjunctival Sutureless 25-Gauge Versus 20-Gauge Standard Vitrectomy: Correlation Between Corneal Topography and Ultrasound Biomicroscopy Measurements of Sclerotomy Sites

Corneal Astigmatism Alteration after Combined Silicone Oil Removal and Cataract Surgery with Intraocular Lens Implantation

Purpose

To explore short-term changes in corneal astigmatism after combined silicone oil removal and cataract (SORC) surgery.

Methods

We enrolled 89 patients (43 men and 46 women). Zeiss IOLMaster was used to measure corneal astigmatism status and axial length on the day before and after the SORC surgery. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were recorded. The results were compared to the outcomes at 3 days, 1 week, and 1 month postoperatively.

Results

Compared to baseline, K1 decreased significantly at 3 days postoperatively (P = 0.016), 1 week (P = 0.009), and 1 month (P = 0.035), while K2 increased significantly at 3 days postoperatively (P = 0.002), 1 week (P < 0.001), and 1 month (P = 0.001), as well as corneal astigmatism (all P < 0.001). Compared to that at the baseline, BCVA significantly improved at 3 days, 1 week, and 1 month postoperatively (all P < 0.001). Meanwhile, IOP decreased significantly at 3 days postoperatively (P < 0.001), 1 week (P = 0.005), and 1 month (P = 0.007). Similarly, axial length decreased at all follow-up time points (all P < 0.001).

Conclusion

Corneal astigmatism increased in the short term after the SORC operation but gradually decreased at 1 month postoperatively. BCVA improved steadily, and SORC was widely used in the clinic.

27-gauge microincision vitrectomy surgery compared with 25-gauge microincision vitrectomy surgery on wound closure and need for wound suture and other postoperative parameters in the treatment of vitreoretinal disease: A meta-analysis

We performed a meta-analysis to evaluate the effect of 27-gauge microincision vitrectomy surgery compared with 25-gauge microincision vitrectomy surgery on wound closure and the need for wound suture and other postoperative parameters in the treatment of vitreoretinal disease. A systematic literature search up to June 2022 was performed and 1264 subjects with the vitreoretinal disease at the baseline of the studies; 562 of them were using the 27-gauge microincision vitrectomy surgery, and 722 were using 25-gauge microincision vitrectomy surgery. Odds ratio (OR), and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of 27-gauge microincision vitrectomy surgery compared with 25-gauge microincision vitrectomy surgery on wound closure and the need for wound suture and other postoperative parameters in the treatment of vitreoretinal disease using the dichotomous, and contentious methods with a random or fixed-effect model. The 27-gauge microincision vitrectomy surgery subjects had a significantly lower intraoperative and postoperative wound complication (OR, 6.66; 95% CI, 0.46-0.95, P = .02), and wound suture number (OR, 0.38; 95% CI, 0.20-0.71, P = .002), and best corrected visual acuity (MD, -0.03; 95% CI, -0.05 to -0.001, P = .02) compared with 25-gauge microincision vitrectomy surgery in subjects with vitreoretinal disease. However, 27-gauge microincision vitrectomy surgery subjects had no significant difference in the wound closure time (MD, -8.45; 95% CI, -23.44 to 6.55, P = .27), operation time (MD, 0.85; 95% CI, -1.17 to 2.86, P = .41), intraocular pressure at postoperative day 1 (MD, 0.42; 95% CI, -1.45-2.28, P = .66), primary anatomical success rate (OR, 0.83; 95% CI, 0.42-1.63, P = .58), and central macular thickness (MD, 1.81; 95% CI, -21.76 to 25.37, P = .88) compared to 25-gauge microincision vitrectomy surgery in subjects with vitreoretinal disease. The 27-gauge microincision vitrectomy surgery subjects had a significantly lower intraoperative and postoperative wound complication, wound suture number, and best corrected visual acuity, and no significant difference in the wound closure time, operation time, intraocular pressure at postoperative day 1, primary anatomical success rate, and central macular thickness compared to 25-gauge microincision vitrectomy surgery in subjects with vitreoretinal disease. The analysis of outcomes should be with caution because of the low sample size of 12 out of 15 studies in the meta-analysis and a low number of studies in certain comparisons.

Evaluation of corneal hysteresis after pars plana vitrectomy combined phacoemulsification and intraocular lens implantation

We evaluated the early effects of pars plana vitrectomy (PPV) on corneal biomechanics by comparing corneal hysteresis (CH) after cataract surgery (phacoemulsification and aspiration with intraocular lens implantation; PEA + IOL) alone and PPV combined with cataract surgery. This study included 20 eyes (18 patients), who underwent cataract surgery alone (PEA + IOL group), and 28 eyes (27 patients) who underwent PPV combined with cataract surgery (PPV triple group). The CH was 11.1 ± 1.1, 10.4 ± 1.1, and 11.0 ± 1.0 mmHg in the PEA + IOL group and 11.0 ± 1.4, 9.8 ± 1.4, and 10.6 ± 1.6 mmHg in the PPV triple group, preoperatively, at 2 weeks, and 3 months after surgery, respectively. The CH was not significantly different after surgery in the PEA + IOL group, but decreased significantly in the PPV triple group 2 weeks following surgery (p < 0.01). Intraocular pressure (IOP) and central corneal thickness (CCT) did not change significantly after surgery in either group. Preoperatively, there was a positive correlation between CH and CCT in the PPV triple group, but the correlation disappeared postoperatively. In PPV combined with cataract surgery, CH temporarily decreased postoperatively, independent of IOP and CCT. Removal of the vitreous may reduce the elasticity and rigidity of the entire eye.

Pars Plana Vitrectomy Port Sizes: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

The uptake of small-gauge (SG; ie, 23-gauge [23-G], 25-gauge [25-G], and 27-gauge [27-G]) pars plana vitrectomy (PPV) has grown. We aim to investigate the advantages and disadvantages of various PPV port sizes in a meta-analysis of randomized controlled trials (RCTs).

MATERIALS AND METHODS

A systematic literature search was performed for RCTs comparing PPV port sizes for any indication. Weighted mean differences (WMDs) and risk ratios (RRs) were calculated, and meta-analysis was performed with random-effects models.

RESULTS

A total of 1,678 eyes from 22 RCTs were included. Risk-of-bias assessment found some concerns in 13 studies. Compared with 20-gauge PPV, there was no significant difference in the final or change in best-corrected visual acuity (BCVA; five studies analyzed each) relative to that of SG PPV. SG PPV was associated with a significantly greater incidence of hypotony (RR = 3.79; 95% confidence intervals [CI], 2.02 to 7.10; P < .0001; six studies) and choroidal detachment (RR = 5.65; 95% CI, 1.01 to 31.71; P = .05; three studies). Compared with 25-G PPV, there was no significant difference in BCVA at any time point with 23-G (two studies), and significantly more frequent port suturing was required with 23-G (RR = 0.46; 95% CI, 0.25 to 0.84; P = .01; two studies). Compared with 25-G PPV, 27-G was associated with a significantly better final BCVA (WMD = -0.06 logMAR; 95% CI, -0.11 to -0.01; P = .02; five studies) and a significantly lengthened surgery (WMD = 4.11 minutes; 95% CI, 0.18 to 8.05; P = .04; three studies).

CONCLUSIONS

There was no significant difference in visual or surgical outcomes following 20-gauge PPV relative to SG PPV (Grading of Recommendations, Assessment, Development, and Evaluation recommendation: low certainty), and there was an increased risk of postoperative complications with SG PPV (moderate certainty). Compared with 25-G PPV, 23-G required more frequent port suturing (moderate certainty), whereas 27-G may be associated with a better final BCVA but longer surgery (low and moderate certainty, respectively). [Ophthalmic Surg Lasers Imaging Retina. 2022;53:152-158.].

SUTURELESS CLOSURE OF 23- AND 25-GAUGE LEAKING SCLEROTOMIES WITH THE SCLERAL NEEDLING TECHNIQUE

PURPOSE

To describe and evaluate the efficacy of a novel technique, scleral needling (SN), for securing 23- and 25-gauge leaking sclerotomies in microincision vitrectomy surgery.

METHODS

A retrospective comparative review of consecutive cases of 23- and 25-gauge pars plana vitrectomy performed by a single vitreoretinal surgeon before the introduction of the SN technique (pre-SN; November 2016 to January 2017) and after the introduction of the SN technique (post-SN; November 2017 to January 2018) was conducted. The SN technique was implemented as an alternative to suturing, using a 30-gauge needle inserted perpendicularly through the full thickness of the sclera adjacent to the scleral opening, with the needle then immediately removed and sclerotomy closure confirmed.

RESULTS

A total of 203 eyes, 105 from pre-SN and 98 from post-SN, were included in the study. The number of eyes requiring suture closure was significantly reduced from 39% in the pre-SN group to 2% in the post-SN group (P < 0.001). The mean postoperative intraocular pressure and incidence of hypotony on Days 1 to 2, Days 3 to 20, and Days 21 to 50 was not significantly different between the pre-SN and post-SN groups. No major complications associated with the SN technique were noted during the study period.

CONCLUSION

The SN technique is a safe and simple method for effectively securing leaking sclerotomies in microincision vitrectomy surgery.

INCIDENCE AND RISK FACTORS FOR HYPOTONY AFTER 25-GAUGE PARS PLANA VITRECTOMY WITH NONEXPANSILE ENDOTAMPONADE

PURPOSE

The purpose of this study was to assess the incidence and risk factors for early postoperative hypotony after 25-gauge pars plana vitrectomy with nonexpansile endotamponade.

METHODS

A retrospective study of consecutive patients who underwent 25-G pars plana vitrectomy. Hypotony was defined as an intraocular pressure of 5 mmHg or less after surgery and ocular hypertension as an intraocular pressure greater than 21 mmHg.

RESULTS

Overall, 307 eyes of 307 patients with a mean age of 61.7 ± 14.3 of which 56.7% were males were included. Hypotony was identified in 5.2% of cases (n = 16) at Day 1 and 0.7% (n = 2) at Week 1 with no hypotony-related complications. The hypotony group had a higher number of previous vitreoretinal surgeries (1.5 ± 1.1 vs. 0.4 ± 0.7, P < 0.001) and a higher prevalence of preoperative ocular hypertension (22.2% vs. 4.8%, P = 0.02), pseudophakia (77.8% vs. 48.4%, P = 0.01), silicone oil removal (61.1% vs. 8.3%, P < 0.001), and external diathermy performed (55.6% vs. 20.1%, P = 0.001). In stepwise multivariate analysis, significant parameters were silicone oil removal (R = 16.34%, odds ratio 13.45, P < 0.001), pseudophakia (R = 5.69%, odds ratio 3.65, P = 0.03), and younger age (R = 2.68%, odds ratio 0.96, P = 0.04).

CONCLUSION

Silicone oil removal is a significant risk factor for early postoperative hypotony after 25-G pars plana vitrectomy.

Vitreous incarceration in sutured vs non-sutured sclerotomies after 25-gauge macular surgery

OBJECTIVES

To study the patterns of vitreous incarceration in sutured vs non-sutured sclerotomies in patients subjected to 25-gauge macular surgery.

METHODS

A prospective study of 135 eyes affected by epiretinal membrane or macular hole. Vitreal disposition was evaluated via ultrasound biomicroscopy (UBM) at the sclerotomy sites between 30 and 40 days after surgery, once the tamponade had completely disappeared.

RESULTS

In total, 349 sclerotomies (86.2%) of 99 patients were non-sutured while 56 sclerotomies (13.8%) of 36 patients were sutured at the end of the surgical procedure. Among the 36 patients with sutured sclerotomies, 15 out of 36 (41.6%) had at least two sclerotomies sutured. All the sclerotomy sites were evaluated (405 sclerotomies). Sclerotomy suture was significantly associated with a less aggressive pattern of vitreal incarceration (OR: 0.16, 95% CI: 0.07-0.35, p < 0.001). Compared to preoperative values, day 1 post operative IOP was not significantly different in patients with sutured sclerotomies, while patients with non-sutured sclerotomies had a significantly lower day 1 post operative IOP.

CONCLUSIONS

In 25-gauge macular surgery, UBM evaluation documented a higher rate of postoperative vitreous incarceration in the non-sutured sclerotomies, confirming the previously postulated role of the residual vitreous, left at the end of the surgery, in closing the sclerotomy site.

Comparison of 27-Gauge and 25-Gauge Microincision Vitrectomy Surgery for the Treatment of Vitreoretinal Disease: A Systematic Review and Meta-Analysis

BACKGROUND

We performed a systematic review and meta-analysis to evaluate the safety and effectiveness of 27-gauge (27-G) microincision vitrectomy surgery (MIVS) compared with 25-guage (25-G) MIVS for the treatment of vitreoretinal disease.

METHODS

A systematic electronic search was conducted in March 2020 in PubMed, Embase, and the Cochrane library. Eligible criteria for including studies were controlled trials comparing 27-G vitrectomy with 25-G vitrectomy in patients with vitreoretinal disease. The main outcomes included operation time; best corrected visual acuity (BCVA) in logMAR; postoperative intraocular pressure (IOP); primary anatomical success rate for rhegmatogenous retinal detachment (RRD) cases and postoperative central macular thickness (CMT) for idiopathic epiretinal membrane (ERM) cases; intraoperative/postoperative complications. Odds ratio (OR) and mean difference (MD) were synthesized under fixed or random effects models.

RESULTS

Eleven studies enrolling 940 eyes were identified. Among those 11 studies, six studies were on the treatment of RRD and five studies were on the treatment of ERM, so subgroup analyses were conducted. The total pooled results indicated that 27-G surgery system had obvious advantages in improving BCVA at six months after the vitrectomy (P = 0.004) and reducing intraoperative/postoperative complications (P = 0.03). However, the mean operation time was significantly longer by three minutes for 27-G compared with 25-G vitrectomy (P = 0.002). In subgroup analyses, for the treatment of ERM cases, 27-G group was associated with less complications and longer operation time. However, for the treatment of RRD cases, 27-G groups and 25-G groups were comparable in operation time, postoperative BCVA, postoperative IOP, and primary anatomical success rate.

CONCLUSIONS

This meta-analysis confirmed that 27-G MIVS was an effective and safe surgical system compared with 25-G MIVS for the treatment of RRD and ERM cases, even though 27-G system needs a longer surgical time.

Comparative analysis of 23-, 25-, and 27-gauge forceps stiffness and related displacement

PURPOSE

To test the stiffness and displacement of different vitreous forceps. Physical features and deformation after multiple procedures were also measured.

METHODS

Eleven different 23-, 25-, and 27-gauge vitreous forceps were studied. The measurements were repeated loading the probe at different distances from the tip: at the top of the tip and 10 and 20 mm from the tip, respectively. For each probe, 10 successive identical bending tests were performed. The total length and the internal and external diameters of each forceps were also measured.

RESULTS

A total of 330 successive identical bending tests were performed. No progression in deformation after the repeated measurements was recorded (p > 0.05). In each gauge group, displacement differences were detected according to the manufacturing metal properties, the total length, and the thickness of the shaft wall. A minimal adequate model to describes forceps displacements in terms of their significant predictors, such as gauge, model, and load distance from the tip, was created.

CONCLUSION

We provided a precise assessment of the stiffness and displacement of different vitreous forceps to enable surgeons to select the optimal instrument according to the benefits and limitations of each forceps.

Analysis of Changes in Corneal Topography after 27-Gauge Transconjunctival Microincision Vitrectomy Combined with Cataract Surgery

Purpose

To investigate changes in the corneal shape before and after vitrectomy, over a period of time, using a 27-gauge system.

Methods

Forty-five eyes underwent a combination of cataract surgery and vitrectomy. The surgeries were performed using a 27-gauge transconjunctival vitrectomy system, in which the corneal topography could be performed up to three months after the surgery. The surgeries were performed for an epiretinal membrane in 11 eyes, a macular hole in 14 eyes, and rhegmatogenous retinal detachment in 20 eyes. All of the surgeries were performed by the same surgeon, and in all cases, a 4-port 27-gauge vitrectomy device was used. Cataract surgery in all patients was performed with a 2.4 mm corneoscleral incision at 11 o'clock. The surgeries were performed without suturing the operative wound in all cases. Corneal topography was performed using a TMS-4 topographer (Tomey Corporation, Tokyo, Japan). The examinations were performed the day before and 1 day, 1 week, 1 month, and 3 months after the surgery. The results of corneal topography for the spherical, regular astigmatic, asymmetric, and high-order irregular astigmatic components were compared before and after surgery.

Results

No significant differences were seen in any of the components in the epiretinal membrane group, but significant differences were seen in the asymmetric components and the high-order irregular astigmatic components between the macular hole and rhegmatogenous retinal detachment groups (p < 0.05). There were no significant changes in intraocular pressure on any measurement time in the postoperative period compared to preoperative intraocular pressure.

Conclusion

Irregular astigmatism was seen after surgery when 27-gauge vitrectomy with a 4-port system was performed together with cataract surgery with a 2.4 mm incision.

Comparative study of straight vs angled incision in 27-gauge vitrectomy for epiretinal membrane

Purpose

The purpose of this study was to compare straight and angled incisions in 27-gauge microincision vitrectomy in patients with epiretinal membrane (ERM).

Methods

Seventy-three eyes of 68 patients with ERM who underwent straight (35 eyes) or angled incision (38 eyes) for 27-gauge microincision vitrectomy were retrospectively evaluated.

Results

No statistically significant difference was found between the two groups in postoperative logarithm of minimal angle of resolution best-corrected visual acuity. The intraocular pressure and rate of hypotony 1 day postoperatively did not differ between the straight- and angled-incision groups (intraocular pressure: 11.5 vs 13.4 mmHg, respectively; rate of hypotony: 20% vs 8%, respectively). Surgical wound closing occurred by postoperative day 10 in both groups.

Conclusion

A straight incision is as safe and useful in ERM vitrectomy as an angled one.

Evaluation of corneal topographic changes and surgically induced astigmatism after transconjunctival 27-gauge microincision vitrectomy surgery

PURPOSE

To evaluate the corneal topographic changes and postvitrectomy astigmatism after 27-gauge (g) microincision vitrectomy surgery (MIVS) by using Pentacam HR-Scheimpflug imaging system.

METHODS

This prospective descriptive study included 30 eyes of 30 patients who underwent 27-g MIVS. All eyes underwent a Pentacam HR examination preoperatively and on the first week, first month and third month postoperatively. The power of the corneal astigmatism, mean keratometry (K m), K 1 and K 2 values and corneal asphericity (Q value) values for the both front and back surfaces of the cornea, index of surface variance (ISV), index of vertical asymmetry (IVA), index of height asymmetry (IHA), index of height decentration (IHD) and higher-order aberrations including coma, trefoil, spherical aberration, higher-order root-mean-square and total RMS were recorded. Additionally, the mean induced astigmatism was estimated by vector analysis.

RESULTS

No statistically significant changes were observed in the mean power of corneal astigmatism, mean keratometry, K 1 and K 2 values, corneal asphericity values, ISV, IVA, IHA, IHD and higher-order aberrations on the first week, first month and third month after the operation. The mean surgically induced astigmatism was calculated as 0.23 ± 0.11 D on the first week, 0.19 ± 0.10 D on the first month and 0.19 ± 0.08 D on the third month postoperatively.

CONCLUSION

Minor corneal surface and induced astigmatic changes are expected to result in rapid visual rehabilitation after pars plana vitrectomy with the 27-g MIVS system.

VITREOUS INCARCERATION IN SCLEROTOMIES AFTER VALVED 23-, 25-, OR 27-GAUGE AND NONVALVED 23- OR 25-GAUGE MACULAR SURGERY

PURPOSE

To study the patterns of vitreous incarceration at sclerotomy sites by ultrasound biomicroscopy in patients subjected to valved or nonvalved small-gauge pars plana vitrectomy.

METHODS

A prospective comparative study of 88 eyes affected by epiretinal membrane and macular hole. Patients were divided into four groups: valved or nonvalved 23-gauge (16 eyes each) and valved or nonvalved 25-gauge (20 eyes each); their vitreal disposition was compared by ultrasound biomicroscopy. Vitreal disposition was also assessed in 16 eyes of 16 patients subjected to valved 27-gauge pars plana vitrectomy.

RESULTS

Three vitreal patterns were identified: P0 (vitreous not visible or vitreous strand distant from the sclerotomy site), P1 (vitreous strand parallel to and in contact with the sclerotomy site), and P2 (vitreous strand entrapped in the sclerotomy site). The effect of valved trocar use on vitreous incarceration seemed to be somewhat beneficial, but no statistically significant effect could be shown (odds ratio: 0.85, 95% confidence interval: 0.42-1.74, P = 0.657). Similarly, no differences in vitreous incarceration were shown among vitrectomy gauges (23, 25, or 27) both in a model including valved trocars only (P = 0.858) and in a model with all available data (P = 0.935).

CONCLUSION

In 23- and 25-gauge macular surgeries, postoperative vitreous incarceration does not seem to be reduced using valved cannulas and was similar to that observed in 27-gauge surgery.

Comparison of subconjunctival scarring after microincision vitrectomy surgery using 20-, 23-, 25- and 27-gauge systems in rabbits

PURPOSE

To compare subconjunctival scarring after vitrectomy in rabbit eyes using different gauge systems by analysing anterior segment optical coherence tomography (AS-OCT) images and histological sections.

METHODS

Vitrectomy using 20-, 23-, 25- and 27-gauge systems was performed for rabbits. Anterior segment optical coherence tomography (AS-OCT) images of the incision sites were obtained before and at day 1, 7 and 1 month after surgery. We measured the thickness of conjunctival epithelium, stroma, Tenon's capsule and total conjunctiva of these three layers, then determined the preservation rates of the borderlines between each layer. Surgical invasion was estimated by histological observation.

RESULTS

The thickness of total conjunctiva, or the thickness of both conjunctival stroma and Tenon's capsule in the 20-gauge group was significantly thicker than that in the 27-gauge group at day 1 and day 7 after surgery. Preservation rates of the conjunctival stroma/Tenon's capsule borderline were significantly lower in the 20-gauge group than in the 25- and 27-gauge groups at day 1, day 7 and 1 month. Preservation rates of the Tenon's capsule/sclera borderline were significantly lower in the 20-gauge group than in the 25- and 27-gauge groups at 1 month. In the 27-gauge group, the number of α-smooth muscle actin-positive fibroblasts was significantly smaller than in the 20-gauge group at day 7.

CONCLUSION

Based on the finding of AS-OCT and histology, micro incision vitreous surgery, especially using 27-gauge, contributed to less subconjunctival scarring postoperatively. Therefore, the 27-gauge pars plana vitrectomy (PPV) may be a more effective technique for preserving the structure of conjunctiva.

Comparison of Transcorneal and Pars Plana Routes in Pediatric Cataract Surgery in Infants Using a 25-Gauge Vitrectomy System

PURPOSE

To demonstrate and compare the performance of the 25-gauge transconjunctival sutureless vitrectomy system via anterior (transcorneal) and posterior (pars plana) routes in congenital cataracts in infants.

METHODS

In this prospective interventional study, 12 pediatric patients younger than 1 year with bilateral congenital cataract were included to undergo cataract surgery with posterior vitreorhexis and limited anterior vitrectomy using a 25-gauge vitrectomy system. One eye of each patient was operated on by the anterior (transcorneal) route and the other by the posterior (pars plana) route. All eyes were left aphakic. Intraoperative and postoperative (12 months after surgery) results were compared between the two routes, including visual axis opacification and astigmatism. All eyes were rehabilitated with contact lenses or spectacles.

RESULTS

The 25-gauge vitrectomy system allowed excellent intraoperative control in both groups. Postoperatively, there was minimal conjunctival congestion, corneal edema, and inflammatory reaction. No intra-operative or postoperative complications were noted in any eye. All eyes had a clear visual axis 12 months after surgery. Mean spherical equivalent was 15.50 ± 2.28 diopters (D) and mean astigmatism was 0.25 ± 0.45 D in the transcorneal group, whereas in the pars plana group it was 15.46 ± 2.45 D and 0.16 ± 0.39 D, respectively, at 12 months, the difference being statistically insignificant (P > .05).

CONCLUSIONS

The 25-gauge vitrectomy system allows sutureless surgery with excellent intraoperative control and minimal postoperative inflammation and astigmatism with clear visual axis by both the transcorneal and pars plana routes.

Influence of the source of incisional vitreous incarceration on sclerotomy closure competency after transconjunctival sutureless vitrectomy

PURPOSE

To evaluate the influence that the origin of incisional vitreous incarceration may have on the presence of postoperative conjunctival blebs over sclerotomies after transconjunctival sutureless vitrectomy (TSV). Blebs are formed by incisional leakage due to incompetent closure.

METHODS

Twenty-three-gauge TSV was performed in 83 cadaveric pig eyes. Once each vitrectomy was finished, ultrasound biomicroscopy (UBM) was used to assess the presence of postoperative conjunctival blebs over the sclerotomy sites, as well as the existence of vitreous incarcerated in incisions. Vitreous strands may come from the perisclerotomy area, running parallel to the sclera toward the inner hole of the sclerotomies, or may radiate from the core of the vitreous cavity.

RESULTS

Vitreous entrapment was found in 73.9% of the sclerotomies; 43.4% of the incisions showed vitreous strands coming parallel to the sclera (12.9% of them showed conjunctival bleb), 19.7% of the wounds presented vitreous aiming toward the core of the vitreous cavity (2% of them had conjunctival bleb) and 10.8% of the entrances presented both vitreous incarceration sources (none of them showed bleb). Incisions with vitreous entrapment parallel to the sclera were associated with a significantly greater sclerotomy leakage rate.

CONCLUSIONS

Sclerotomies with vitreous incarceration coming from the core of the vitreous cavity showed a greater incisional closure competency than that observed in incisions with vitreous entrapment coming from the pericannular area; if these results were confirmed in humans, different postoperative suture rates may be expected on sclerotomies according to the vitrectomy degree performed in different areas of the vitreous cavity.

25-gauge microincision vitrectomy to treat vitreoretinal disease in glaucomatous eyes after trabeculectomy

Purpose. To determine the feasibility of using 25-gauge microincision vitrectomy surgery (25GMIVS) to treat vitreoretinal disease in glaucomatous eyes which have previously undergone trabeculectomy (TLE). Methods. A consecutive, interventional case series. We performed 25GMIVS in 15 glaucomatous eyes that had undergone TLE. Follow-up period was 11.5 months. Results. 25GMIVS was successfully used and led to improvement in visual acuity (P < 0.01). We performed 25GMIVS for proliferative diabetic retinopathy with neovascular glaucoma in 53% of eyes (8 of 15). Although 3 eyes needed further TLE following 25GMIVS, final IOP was below 21 mmHg in all eyes except one eye (93%) and was comparable to pre-25GMIVS IOP (P = 0.20) without an increase in the number of glaucoma medications (P = 0.14). Conclusions. 25GMIVS is a feasible treatment for vitreoretinal disease in eyes with preexisting TLE, effective in both significantly improving BCVA and preserving the filtering bleb, while not excluding further glaucoma surgery.

Anatomic and functional outcomes of 25-gauge vitrectomy for repair of eyes with rhegmatogenous retinal detachment complicated by proliferative vitreoretinopathy

Background

The purpose of this study was to evaluate the outcome of 25-gauge vitrectomy for repair of rhegmatogenous retinal detachment (RRD) complicated by proliferative vitreoretinopathy (PVR).

Methods

Twenty-seven eyes of 27 patients who had undergone 25-gauge vitrectomy for grade C PVR were investigated retrospectively. The surgical procedures, anatomic success, and best-corrected visual acuity were assessed.

Results

The mean number of operations was 1.4 (range 1–4). During the 25-gauge vitrectomy, 20-gauge instruments were needed in eleven eyes (40.7%) to remove resilient fibrous preretinal membranes, to extract subretinal proliferations, or to remove or infuse silicone oil. The retina was reattached in 21 eyes (77.8%) after the initial vitrectomy and in 25 eyes (92.6%) at the final examination. The mean best-corrected visual acuity in logarithm of the minimal angle of resolution units was 1.36 ± 0.81 before vitrectomy and 0.79 ± 0.71 at one month, 0.73 ± 0.72 at 3 months, 0.73 ± 0.75 at 6 months, and 0.75 ± 0.78 at 12 months after vitrectomy. The best-corrected visual acuities were significantly improved compared with the preoperative ones at all postoperative assessments (P<0.001).

Conclusion

Twenty-five gauge vitrectomy is a relatively safe and efficacious method of treating RRD with PVR, although combined use of 20-gauge instruments may be needed for certain surgical procedures.

Safety of 20-gauge transconjunctival sutureless vitrectomy

PURPOSE

To study the safety of 20-gauge transconjunctival sutureless vitrectomy.

METHODS

Clinical data of patients who underwent 20-gauge transconjunctival sutureless vitrectomy for the first time, for various disorders, were reviewed retrospectively. The main outcome measures were the number of sclerotomies requiring suturing as well as the intra- and postoperative complications.

RESULTS

A total of 179 operations were performed. Indications for vitrectomy included 68 idiopathic epiretinal membranes, 26 macular holes, 23 phakic and 16 pseudophakic retinal detachments, and 46 various other, less common etiologies. Of these 179 operations, 166 (93%) were sutureless. Of the 537 sclerotomies created, 25 (5%) received a single transconjunctival-scleral suture. Intraoperative complications included premature dislodging of the cannulas in 2 sclerotomies and an iatrogenic horseshoe tear at 1 sclerotomy site. Postoperative complications comprised transient hypotony in 14 cases, subconjunctival gas in 2 cases, and choroidal effusion in 1 case. No serious complications (such as endophthalmitis) were observed.

CONCLUSION

20-gauge transconjunctival sutureless vitrectomy can be considered safe, as the intra- and postoperative complications observed are neither numerous nor significant. Sclerotomies appear to be safe and relatively easy to perform, without compromising the advantages of sutureless surgery.

Influence of sclerotomy use on vitreous incarceration in an experimental model of vitrectomized eye

PURPOSE

To evaluate the influence of sclerotomy use during vitrectomy (vitreous cutter, illumination probe, or infusion-line entrance) on postoperative vitreous incarceration using an experimental model of vitrectomized eye.

MATERIALS AND METHODS

Experimental, randomized, and observer-masked study in which 23-gauge transconjunctival sutureless vitrectomy was performed in cadaveric pig eyes. Postoperative incisional vitreous entrapment was evaluated by direct visualization. No vitreous incarceration was classified as grade 0 (G0), thin vitreous entrapment was classified as grade 1 (G1), and thick vitreous strands as grade 2 (G2).

RESULTS

A total of 46 eyes were included. Vitreous incarceration was detected in 91.3% (43.5% G1, 47.8% G2) of the sclerotomies used by the vitreous cutter probe, 95.7% (45.7% G1, 50% G2) of the illumination-pipe entrances, and 93.5% (45.7% G1, 47.8% G2) of the infusion-line incisions. No statistical differences were found when comparing incisional vitreous incarceration after vitrectomy according to sclerotomy use.

CONCLUSION

Different manipulation of the sclerotomies, depending on their use, does not seem to influence postvitrectomy vitreous entrapment in our experimental model.

Evaluation of conjunctival bleb detection after vitrectomy by ultrasound biomicroscopy, optical coherence tomography and direct visualization

PURPOSE

To compare ultrasound biomicroscopy (UBM), anterior-segment optical coherence tomography (AS-OCT), and direct visualization for detecting conjunctival blebs in sutureless sclerotomies after vitrectomy. Conjunctival blebs are formed by sclerotomy leakage due to incompetent closure.

METHODS

Experimental, randomized, and observer-masked study in which 23-gauge vitrectomies were performed in cadaveric pig eyes. Postoperative conjunctival blebs were assessed by UBM, AS-OCT, and direct visualization. No conjunctival blebs were classified as Grade 0 (G0), thin blebs (less than or equal to one-half of scleral thickness) as Grade 1 (G1) and thick blebs (greater than one-half of scleral thickness) as Grade 2 (G2).

RESULTS

Fifty pig eyes were included. Conjunctival blebs were found in 13.3% (8% G1, 5.3% G2) of the incisions analyzed by UBM, in 20% (14.7% G1, 5.3% G2) of the sclerotomies studied by AS-OCT, and in 7.3% (2% G1, 5.3% G2) of the wounds evaluated by direct visualization. AS-OCT was the most sensitive method for identifying conjunctival blebs when compared with UBM and direct visualization (p<0.001). In turn, UBM was better than direct visualization for observing sclerotomy blebs (p=0.004).

CONCLUSIONS

AS-OCT is the most sensitive technique for detecting subclinical blebs (G1) and thus, it may be useful in research for studying the influence that surgical factors and maneuvers may exert on sclerotomy closure capacity after vitrectomy. Direct visualization, that is used in routine clinical practice to determine which sclerotomies should be sutured, is useful only to identify thick blebs (G2) after vitrectomy.

Combined 25-gauge microincision vitrectomy and toric intraocular lens implantation with posterior capsulotomy

PURPOSE

To evaluate the efficacy of combined 25-gauge microincision vitrectomy surgery (MIVS) and toric intraocular lens (IOL) implantation with posterior capsulotomy.

METHODS

Noncomparative, interventional case series performed at a single center. Twelve patients with vitreoretinal disease and cataracts, with preexisting regular corneal astigmatism greater than 1 diopter, underwent 25-gauge MIVS and toric IOL implantation with posterior capsulotomy.

RESULTS

The toric IOL was successfully implanted in each case. At 6 months postoperatively, mean axis rotation was 5.7° ± 3.1°. At 1 month postoperatively, mean uncorrected and best corrected visual acuity improved; the improvement was maintained after 6 months. The absolute residual refractive cylinder was significantly lower postoperatively than the pre-existing regular corneal cylinder (P = .003). There were no surgical complications except temporary posterior iris synechiae in one case.

CONCLUSIONS

Combined 25-gauge MIVS and toric IOL implantation with posterior capsulotomy is a practical and safe method to treat vitreoretinal disease and cataracts with pre-existing corneal astigmatism.

Combined 25-gauge vitrectomy and cataract surgery with toric intraocular lens with idiopathic epiretinal membrane

PURPOSE

To evaluate the stability of axis rotation, astigmatism correction, and improvement in uncorrected distance visual acuity (UDVA) up to 6 months postoperatively using an astigmatism-correcting intraocular lens (IOL) in a 25-gauge transconjunctival sutureless vitrectomy combined with cataract surgery.

SETTING

Department of Ophthalmology, Kagawa University Faculty of Medicine, Kagawa, Japan.

DESIGN

Prospective nonrandomized interventional study.

METHOD

Eyes with a preoperative corneal cylinder of more than 0.75 diopter (D) had a triple procedure for idiopathic epiretinal membrane (ERM) using an Acrysof IQ toric IOL. Outcome measures were the amount of IOL axis rotation up to 3 months postoperatively, UDVA, corrected distance visual acuity, and corneal and refractive astigmatism up to 6 months postoperatively. A comparison was performed between patients with a target postoperative spherical refraction of emmetropia (toric emmetropic group) and patients who previously had a triple procedure for idiopathic ERM using a nontoric IOL (control group).

RESULTS

The mean IOL axis rotation from the end of surgery until 3 months postoperatively was 3.67 degrees ± 3.13 (SD). Six months postoperatively, the mean corneal and refractive cylinders were 1.32 ± 0.61 D and 0.51 ± 0.31 D, respectively, showing a significant difference (P<.0001, paired t test). In addition, the mean UDVA was significantly improved 6 months postoperatively in the control and toric emmetropic group (0.57 logMAR versus 0.35 logMAR) (P=.028), although the toric group was more improved than the control group.

CONCLUSION

In vitrectomy (triple procedure) for idiopathic ERM with a toric IOL, postoperative IOL axis stability was similar to that reported for cataract surgery alone. Furthermore, the UDVA was better than with implantation of a spherical IOL.

Transconjunctival sutureless vitrectomy versus 20-gauge vitrectomy for vitreoretinal surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Transconjunctival sutureless vitrectomy is appealing to vitreoretinal surgeons around the world. However, its use versus 20-gauge vitreoretinal surgery is still controversial. The aim of this meta-analysis was to compare the safety and functional outcomes of transconjunctival sutureless vitrectomy versus 20-gauge vitrectomy for vitreoretinal surgery.

METHODS

Data sources, including PubMed, Medline, EMBASE, and Cochrane Controlled Trials Register, were searched to identify potentially relevant randomized controlled trials. A meta-analysis was performed using RevMan 5.0 software. The primary factors included patients' discomfort, operating time and early postoperative complications. Visual acuity and surgically induced astigmatism were chosen as secondary outcomes.

RESULTS

A total of 471 participants with 479 eyes in eight trials between 2005 and 2011 were analyzed. Transconjunctival sutureless vitrectomy was associated with significantly fewer patients suffering from postoperative discomfort at 1 day (odds ratio [OR] 0.07; 95 % confidence interval [CI] 0.01 to 0.49; p = 0.007) and 7 days (OR 0.14; 95 % CI 0.03 to 0.73; p = 0.02) follow-up, and was more effective in reducing surgically induced astigmatism (mean difference -0.23D; 95 % CI -0.31 to -0.15; p < 0.00001) compared to 20-gauge vitrectomy. The sutureless group achieved shorter wound opening (mean difference -1.97 minutes; 95 % CI -2.69 to -1.25; p < 0.00001) as well as wound closure time (mean difference -4.55 minutes; 95 % CI -5.43 to -3.66; p < 0.00001), but the overall surgery time was comparable (mean difference -0.14 minutes; 95 % CI -3.52 to 3.24; p = 0.93). There were no significant differences in the complication rates between the two groups with the exception of postoperative hypotony, which was more likely with the sutureless group (OR 3.73; 95 % CI 1.43 to 9.76; p = 0.007).

CONCLUSIONS

According to the present data, transconjunctival sutureless vitrectomy offered significantly less postoperative discomfort and decreased surgically induced astigmatism without increasing the risk of vision-threatening complications. Further trials with contemporary equipment and larger sample size are suggested to confirm this conclusion.

Effect of interposition maneuver during cannula removal on vitreous incarceration rate in vitrectomized eyes measured by ultrasound biomicroscopy

PURPOSE

To evaluate the influence of the cannula removal maneuver on the postoperative incisional vitreous incarceration using an experimental model of vitrectomized eye.

METHODS

Prospective, experimental, randomized and observer-masked experimental study in which 23-gauge transconjunctival sutureless vitrectomy was performed through oblique sclerotomies in cadaveric pig eyes. Once the vitrectomy was finished, one of the superior cannulas was removed with the light probe introduced through it, and the other cannula was extracted with the cannula plug inserted. Postoperative incisional vitreous incarceration was evaluated by ultrasound biomicroscopy (UBM).

RESULTS

60 eyes included. Considering the 60 superior sclerotomies whose cannulas were extracted with the light pipe inserted, vitreous incarceration was observed in 35% of them. On the other hand, 71.6% of the incisions whose cannulas were removed with the cannula plug inserted showed vitreous incarceration (p = 0.00013).

CONCLUSIONS

Interposing the light probe through the cannula when it is removed seems to reduce the postoperative wound vitreous incarceration rate in our experimental model.

Minimal refractive change induced by sutureless 23- and 25-gauge pars plana vitrectomy

BACKGROUND AND OBJECTIVE

This study reports the induced refractive error after 23- and 25-gauge (G) pars plana vitrectomy (PPV).

PATIENTS AND METHODS

In this non-randomized retrospective case series, refractive status was assessed with an autokeratorefractometer 1 week or more before and 6 months after surgery. Patients who had suture placement to close the sclerotomies were excluded from the study.

RESULTS

Among the 50 patients (50 eyes), the mean age was 63 years (range: 42 to 76 years) and 57% were female. Thirty eyes underwent 23-G PPV and 20 eyes underwent 25-G PPV. The mean refractive change was +0.50 diopters (D) sphere, +0.25 D cylinders and the mean axis of cylinder change was 6° for the 23-G group; the mean refractive change was +0.12 D sphere, +0.12 D cylinders and the mean axis of cylinder change was 17° for the 25-G group.

CONCLUSION

Following sutureless small-gauge vitrectomy, there were mild and minimally significant refractive changes in the 23-G and 25-G groups from baseline.

Study of intraocular pressure after 23-gauge and 25-gauge pars plana vitrectomy randomized to fluid versus air fill

PURPOSE

To determine if a difference in intraocular pressure (IOP) exists after small-gauge pars plana vitrectomy randomized to fluid versus 80% sterile air fill.

METHODS

Ninety-two eyes undergoing 23-gauge and 25-gauge transconjunctival pars plana vitrectomy were randomized to fluid versus air fill, and IOP was measured at 5 different time points.

RESULTS

There is no difference in the mean IOP for eyes undergoing small-gauge pars plana vitrectomy randomized to fluid versus air fill after vitrectomy. Using 23-gauge instrumentation, the mean immediate and 2-hour postoperative IOPs were statistically lower than the mean preoperative IOP. The mean Postoperative Day 1 and Week 1 IOPs were statistically higher than the mean immediate postoperative IOP. Using 25-gauge instrumentation, the mean IOP was not statistically different at any time points in the 2 groups. When comparing 23-gauge with 25-gauge instrumentation, the immediate postoperative IOP was statistically lower and the rate of suture closure for sclerotomies was higher for 23-gauge vitrectomy.

CONCLUSION

When performing 23-gauge or 25-gauge pars plana vitrectomy, there was no difference in mean IOP for fluid- versus air-filled eyes. However, the mean IOP in the immediate postoperative period was statistically lower, and there was a higher rate of suture closure for 23-gauge compared with 25-gauge instrumentation.

Advantages and limitations of small gauge vitrectomy

Small gauge vitrectomy utilizing 23- and 25-gauge instrumentation has definite advantages, but also limitations, due to the physics of smaller instruments and sutureless surgery. Higher infusion and aspiration pressures are needed to remove the vitreous using 23- and 25-gauge probes. The advantages include decreased surgical times, less tissue manipulation, reduced inflammation and pain postoperatively with more rapid visual recovery. A disadvantage is greater instrument flexion than 20-gauge probes, making small gauge vitrectomy more appropriate for indications such as vitreous opacities, epiretinal membranes, macular holes, and simple retinal detachments. There are also some increased complications related to small gauge vitrectomy, including dislocation of cannulas intraoperatively, early postoperative hypotony, choroidal detachment, and possibly an increased risk of infectious endophthalmitis.