A comparison of induced astigmatism in 20- vs 25-gauge vitrectomy procedures

Complications in Retinal Surgery: A Review of Corneal Changes Following Vitreoretinal Procedures

Purpose:

The purpose of this article is to discuss the early- and late-onset corneal complications that can occur following vitreoretinal surgery.

Methods:

A systematic review of the literature was conducted using PubMed and Google Scholar databases. Articles detailing the clinical findings and the associations between surgical techniques, irrigating solutions, and microsurgical instruments used for vitreoretinal surgery and postoperative corneal complications were included in this review.

Results:

Vitreoretinal surgery can be associated with corneal complications such as persistent corneal epithelial defects, neurotrophic keratopathy, band keratopathy, ocular surface disruption, and endothelial cell damage. Risk factors for the development of cornea complications after posterior segment surgery include history of uncontrolled diabetes mellitus, aphakia or pseudophakia, disrupted anterior lens capsule integrity, use of irrigating solutions without appropriate buffers, use of contact viewing lenses intraoperatively, intraocular gases or silicone oil after vitrectomy, and prolonged duration of surgery.

Conclusions:

Corneal complications secondary to vitreoretinal surgery are multifactorial, but more commonly arise in diabetic patients, those with preexisting ocular comorbidities, and under certain surgical-related conditions. Special pre-, peri-, and postoperative considerations, with a focus on early identification and management of risk factors, are required to help decrease the incidence of corneal complications.

Long-term Analysis of Surgically Induced Astigmatism after Combined Vitrectomy and Cataract Surgery versus Cataract Surgery Alone

Purpose: To compare the long-term changes in surgically induced astigmatism (SIA) in patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together with patients who underwent cataract surgery only.Methods: We retrospectively reviewed SIA changes for 1 year after surgery in patients who received only cataract surgery using phacoemulsification (group 1) and patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together (group 2). Flat keratometry (K1), steep keratometry (K2), and astigmatism axis were measured with automatic keratometry before and after the surgery. Vector analysis was used to calculate SIA at 1, 3, 6, and 12 months postoperatively. We then examined whether the SIA values at each time point were different between the two groups.Results: A total of 86 eyes were included in this study (group 1, n = 45; group 2, n = 41). The mean SIA values calculated at 1, 3, 6, and 12 months after surgery in group 1 were 0.83 ± 0.37, 0.69 ± 0.39, 0.60 ± 0.33, and 0.59 ± 0.33, respectively. In group 2, the values were 0.82 ± 0.47, 0.69 ± 0.38, 0.62 ± 0.28, and 0.61 ± 0.30, respectively. Over time, SIA decreased in both groups (all p < 0.001). There was no significant difference in the mean SIA between the two groups at each follow-up time point after surgery (p = 0.296, p = 0.728, p = 0.361, and p = 0.356, respectively).Conclusions: When 23-gauge sutureless vitrectomy and cataract surgery were performed together, the astigmatism change caused by surgery did not show a significant difference compared with that of the group who received cataract surgery only. Thus, 23-gauge sutureless vitrectomy may not significantly affect corneal astigmatism.

The corneal effects of intravitreal dexamethasone implantation

Objectives:

To evaluate the corneal effects of the intravitreal dexamethasone implantation using corneal topography and specular microscopy.

Material and methods:

27 eyes of the 27 patients who received a single intravitreal dexamethasone implantation dose for diabetic macular edema were enrolled in this study. Sirius topography and EM-3000 specular microscopic examinations were performed at the initial examination (baseline), and then on the first day, during the first week, and 1 month after IDI. Changes in corneal parameters were investigated.

Results:

The mean age was 58.66 ± 6.59 years. 15 patients were men, and 12 were women. The mean disease duration was 12.2 ± 2.4 months, and mean glycosylated hemoglobin (HbA1c) was 7.2 ± 1.1. After dexamethasone injection, the mean central corneal thickness, endothelial cell density, and coefficient variation of cell area presented a statistically significant decrease (p < 0.05). Anterior segment parameters, such as anterior chamber depth, iridocorneal angle, sim K1 and K2 keratometry, pupillary diameter, horizontal visible iris diameter, and corneal astigmatism did not change (p > 0.05).

Conclusion:

Intravitreal dexamethasone implantation affects corneal endothelial cell structure but does not appear to affect corneal topography parameters.

Clinical factors contributing to postoperative aqueous flare intensity after 27-gauge pars plana vitrectomy for the primary rhegmatogenous retinal detachment

PURPOSE

To investigate the perioperative clinical factors, which contribute to the postsurgical aqueous flare intensity (AFI) following 27-gauge pars plana vitrectomy (27GPPV) for primary rhegmatogenous retinal detachment (RRD).

STUDY DESIGN

Retrospective clinical study.

METHODS

We performed retrospective analyses of the medical records of 47 eyes of 47 patients with primary RRD who had undergone 27GPPV with a wide-angle viewing system. AFI was measured preoperatively and 1 week, 1 month, 3 months, 6 months, and 12 months after the surgery.

RESULTS

AFI was significantly increased 1 week after the surgery (p<0.01) and then decreased overtime. At 6 months after surgery it was still statistically significantly higher than preoperative AFI (p=0.03). There was no statistical difference between preoperative AFI and that at 12 months following surgery. Multiple regression analyses revealed that the number of retinal photocoagulations and the performance of scleral indentation had significant positive correlation with AFI at 1 week, 1 month, 3 months, and 6 months, and at 1 month and 3 months after the surgery, respectively.

CONCLUSION

Intraoperative retinal photocoagulation and scleral indentation are probable causes of increased AFI after 27G PPV for RRD.

Comparison of 25- and 27-Gauge Pars Plana Vitrectomy in Repairing Primary Rhegmatogenous Retinal Detachment

Aim

To compare the anatomic and visual outcomes of 25-gauge (25G), and 27-gauge (27G) transconjunctival sutureless pars plana vitrectomy (TSV) for the management of primary rhegmatogeneous retinal detachment (RRD).

Design

A retrospective nonrandomized clinical trial.

Methods

A retrospective comparative analysis of 62 consecutive eyes from 62 patients with 6 months of follow-up was performed.

Results

Thirty-two patients underwent 25G TSV, and 30 patients underwent 27G TSV for the treatment of primary RRD. There was no significant difference in baseline demographic and preoperative ocular characteristics between the two groups. The initial and final anatomical success rates were 93.8% and 100% in 25G TSV and 96.7% and 100% in 27G TSV, respectively (p=1 and p=1, resp.). Preoperative best-corrected visual acuity (BCVA) (logMAR) was 0.44 ± 0.69 and 0.38 ± 0.61 for 25G and 27G TSV, respectively (p=0.73). The final follow-up BCVA was 0.07 ± 0.25 and -0.02 ± 0.17 for 25G and 27G TSV, respectively (p=0.16). The final BCVA was significantly better than the preoperative BCVA in both groups (p=0.02 and p=0.002, resp.). Preoperative intraocular pressure (IOP) (mmHg) was 13.0 ± 3.5 in 25G TSV and 14.3 ± 2.8 in 27G TSV (p=0.11). IOP did not statistically significantly change in both groups during the follow-up period (p=0.63 and p=0.21, resp.).

Conclusion

The 27G TSV system is safe and useful for RRD treatment as 25G TSV.

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.

Impact of postoperative positioning on the outcome of pars plana vitrectomy with gas tamponade for primary rhegmatogenous retinal detachment: comparison between supine and prone positioning

PURPOSE

To compare the postoperative anatomic success rates and the frequency of complications between prone or supine postoperative positioning after transconjunctival sutureless vitrectomy (TSV) for rhegmatogenous retinal detachment (RRD).

METHODS

All patients underwent primary 27-gauge TSV for the treatment of primary RRD. Patients were divided into two groups as follows: group A was patients instructed to keep strict postoperative prone positioning for a minimum of 8 days. Group B was patients instructed to keep the prone positioning on the day of the surgery followed by supine positioning for minimum of 7 days from the day after surgery.

RESULT

Sixty-two eyes were enrolled (group A: 32, group B: 30). There was no significant difference in baseline data between two groups. The initial and final anatomical success rates were 93.8% and 100% in group A and 93.3% and 100% in group B, respectively (p = 1, p = 1, respectively). Posterior synechia of the iris occurred in one eye in group A and in two eyes in group B (p = 0.61). Macular pucker and retinal fold did not occur in either group. Preoperative intraocular pressure (IOP; mmHg) was 14.5 ± 2.9 in group A and 14.5 ± 2.6 in group B (p = 0.92). Intraocular pressure (IOP) was not statistically different between the groups during the follow-up period (p = 0.36, p = 0.07, respectively).

CONCLUSION

Supine positioning may be an option as a postoperative positioning after TSV and gas tamponade for the treatment of RRD.

Long-term outcomes of sutureless 25-G+ pars-plana vitrectomy for the management of diabetic tractional retinal detachment

PURPOSE

To evaluate the short- and long-term surgical and clinical outcomes in eyes with diabetic tractional retinal detachment (TRD) undergoing 25-G+ pars-plana vitrectomy (PPV).

METHODS

A total of 238 patients were reviewed for inclusion in this study. A retrospective cohort study of 109 eyes of 73 patients operated on for diabetic TRD were included. All eyes received intraocular tamponade of air, sulfur hexafluoride, octofluropropane or silicone oil. All patients were followed up for a minimum period of one year.

RESULTS

The mean age of all patients at surgery was 53.9 years ± 9.2, while the mean duration of diabetes was 18.7 ± 10.4 years. The mean length of follow-up was 923 ± 87 days after surgery (range, 432-1792 days). Thirty-two cases (29.3 %) had an associated rhegmatogenous component. Mean BCVA improved from logarithm minimum angle of resolution (logMAR) 1.17 (20/300) to 0.812 (20/130) (p < 0.05). All eyes underwent intraoperative laser photocoagulation. Primary, single-surgery anatomic reattachment was achieved in 99 eyes (91 %). Final anatomic attachment was achieved in 107 eyes (98 %). There was no statistically significant difference in primary or secondary re-attachment rate in terms of type of tamponade agent used. There were five cases of post-operative hypotony (≤5 mmHg) on postoperative day 1, while 11 eyes had IOP ≥ 30 mmHg. There were no cases of endophthalmitis in our cohort.

CONCLUSIONS

25G+ PPV provides for safe and effective repair of diabetic TRDs. Patients experienced positive functional and anatomic outcomes, with no significant intraoperative complications and minimal postoperative sequelae.

Pars Plana Vitrectomy Combined With Either Secondary Scleral-Fixated or Anterior Chamber Intraocular Lens Implantation

PURPOSE

To compare visual outcomes among eyes that underwent pars plana vitrectomy (PPV) in combination with either anterior chamber intraocular lens implantation (ACIOL) or scleral suturing of posterior chamber lens (PCIOL).

DESIGN

Retrospective comparative case series.

METHODS

All eyes presented with aphakia or luxated or subluxated posterior chamber intraocular lens (IOL) following complicated cataract surgery, trauma, or spontaneous dislocation. Eyes involving visually significant macular pathology, past retinal detachment, follow-up of less than 6 months, and surgeries requiring the removal of an ACIOL were excluded. The main outcomes measured were final best-corrected visual acuity (BCVA) and surgical complication rates.

RESULTS

Fifty-seven eyes met inclusion criteria; median follow-up was 13.2 months. Initial median BCVA for ACIOL patients was logMAR 1.301 (Snellen equivalent 20/400, range 20/20 to light perception); final median BCVA was logMAR 0.477 (Snellen equivalent 20/60, range 20/20 to light perception, P < .001). Initial median BCVA for PCIOL patients was logMAR 1.239 (Snellen equivalent 20/347, range 20/60 to light perception); final median BCVA was logMAR 0.301 (Snellen equivalent 20/40, range 20/20 to hand motions, P < .001). The change in BCVA between the 2 groups over the course of the study was similar (P > .05). More epiretinal membrane (ERM) formations occurred postoperatively in the ACIOL group (P = .011). Other complication rates were similar between both groups.

CONCLUSIONS

PPV with secondary IOL placement is safe and effective, resulting in improved visual outcomes regardless of the technique used. Patients undergoing ACIOL placement have a higher incidence of ERM formation.

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.

Comparative study of 27-gauge vs 25-gauge vitrectomy for epiretinal membrane

PURPOSE

The purpose of this study was to compare 27-gauge (27G) with 25-gauge (25G) microincision vitrectomy in patients with epiretinal membrane (ERM).ParticipantsSeventy-four eyes of 66 patients undergoing 3-port pars plana vitrectomy using 27G or 25G instrumentation.

METHODS

Seventy-four eyes of 66 patients with ERM, who underwent 27G or 25G microincision vitrectomy were prospectively evaluated.

RESULTS

The mean operation time for vitrectomy was significantly longer in the 27G group than in the 25G group (9.9±3.5 vs 6.2±2.7 min, respectively, P<0.0001). No statistically significant difference was found between the two groups in terms of the mean operation time for ERM-inner limiting membrane peeling (27G vs 25G: 20.2±9.9 vs 16.1±9.3 min, P=0.14), although the time for vitreous cutting was longer in the 27G group (9.9±3.5 vs 6.2±2.7 min, respectively, P<0.0001). The flare value, intraocular pressure (IOP), and rate of hypotony 1 day after surgery did not differ between the 27G and 25G groups (flare value: 18.7 vs 17.2; IOP: 8.8 vs 9.7 mm Hg; rate of hypotony: 30 vs 35%, respectively). There was no significant difference in the surgically induced astigmatism between the two groups in the follow-up period. The mean time required for wound closure did not show a significant difference between the 27G and 25G groups (7.7 vs 8.6 weeks, respectively).

CONCLUSION

The 27G system is as safe and useful for ERM vitrectomy as the 25G system. Based on its potential, further improvement of 27G instruments could result in greater efficiency.

A prospective study on postoperative discomfort after 20-gauge pars plana vitrectomy

Purpose

To evaluate postoperative pain and other irritation symptoms after 20-gauge (20G) pars plana vitrectomy.

Materials and methods

A total of 110 consecutive patients were enrolled in our studies, and 87 patients who underwent the conventional 20G pars plana vitrectomy were included in the final analysis. All vitrectomies were performed using the same surgical technique by the same surgeon. Patients were examined before surgery and 1 day, 3 days, 7 days, 1 month, and 2 months postoperatively. The main outcome measures include patient age and sex, intraocular pressure (IOP), ocular pain, pain score, pain medication use, and other irritation symptoms comprising itching, foreign body sensation, burning, photophobia, and dryness. The pain was evaluated using the Numerical Rating Scale scored from 0 to 10.

Results

Postoperative pain was relatively common during the first day after surgery, as it was reported by 43 (49.4%) patients. Then, the prevalence gradually decreased to eleven (12.6%) patients at 2 months. Most patients reported mild or moderate pain, with a pain score of 1–5, but only four patients were given analgesics for ocular pain. A postoperative rise of IOP was noted in 25 patients at day 1. Most of these patients with high IOP reported moderate pain. Other ocular irritation symptoms were varied after surgery. There was still one-quarter of patients that had foreign body sensation and dryness symptoms at month 2 after surgery.

Conclusion

Mild and moderate ocular pain were relatively common after 20G vitrectomy, which is more often associated with elevated IOP. Other irritation symptoms were also presented after surgery and could affect the life quality of patients. Therefore, the discomforts after 20G pars plana vitrectomy should be of concern, and timely management should be provided as part of routine postoperative care.

Surgical induced astigmatism correlated with corneal pachymetry and intraocular pressure: transconjunctival sutureless 23-gauge versus 20-gauge sutured vitrectomy in diabetes mellitus

AIM

To determine the difference of surgical induced astigmatism between conventional 20-gauge sutured vitrectomy and 23-gauge transconjunctival sutureless vitrectomy, and the influence of corneal pachymetry and intraocular pressure (IOP) on surgical induced astigmatism in diabetic patients.

METHODS

This retrospective, consecutive case series consisted of 40 eyes of 38 diabetic subjects who underwent either 20-gauge or 23-gauge vitrectomy. The corneal curvature and thickness were measured with Scheimpflug imaging before surgery and 1wk; 1, 3mo after surgery. We compared the surgical induced astigmatism (SIA) on the true net power in 23-gauge group with that in 20-gauge group. We determined the correlation between corneal thickness change ratio, IOP and SIA measured by Pentacam.

RESULTS

The mean SIAs were 1.082±0.085 D (mean±SEM), 0.689±0.070 D and 0.459±0.063 D at postoperative 1wk; 1, 3mo respectively in diabetic subjects. The vitrectomy induced astigmatisms were declined significantly with time (F 2,36=33.629, P=0.000) postoperatively. The 23-gauge surgery group induced significantly less astigmatism than 20-gauge surgery group (F -1,37=11.046, P=0.020). Corneal thickness in diabetes elevated after surgery (F 3,78=10.532, P=0.000). The linear regression analysis at postoperatively 1wk went as: SIA=-4.519+4.931 change ratio (Port3) +0.026 IOP (R(2)=0.46, P=0.000), whereas the rate of corneal thickness change and IOP showed no correlation with the change of astigmatism at postoperatively 1 and 3mo.

CONCLUSION

There are significant serial changes in both 20-gauge and 23-gauge group in diabetic subjects. 23-gauge induce less astigmatism than 20-gauge and become stable more rapidly than 20-gauge. The elevation of corneal thickness and IOP was associated with increased astigmatim at the early postoperative stage both in 23-gauge and 20-gauge surgery group.

25-Gauge pars plana vitrectomy for ciliary block (malignant) glaucoma

To evaluate the efficacy of 25-ga pars plana vitrectomy (PPV) and 25-ga PPV combined with phacoemulsification surgery for managing ciliary block (malignant) glaucoma. The medical records of 11 eyes, in nine consecutive patients with malignant glaucoma were retrospectively reviewed to determine the efficacy of 25-ga PPV for alleviating this disease. All phakic eyes underwent phacoemulsification surgery during vitrectomy. Control of intraocular pressure (IOP), pre- and postoperative best-corrected visual acuity (BCVA), and development of intra- and postoperative complications were evaluated during follow-up. Malignant glaucoma was promptly resolved, and recurrence was not observed during a mean follow-up period of 12.7 ± 3.2 (range 6-18) months. The mean IOP decreased from 35.9 ± 2.9 mmHg, preoperatively, to 16.0 ± 1.4 mmHg, measured at last visit (P = 0.013). Although IOP control was achieved in all eyes after surgery, two eyes required long-term topical antiglaucoma medication. The mean logarithm of the minimum angle of resolution BCVA improved from +0.69 ± 0.11, preoperatively, to +0.29 ± 0.07, postoperatively (P = 0.027). No severe intraoperative complications were observed. Postoperative complications mostly occurred during the first week after surgery, including transient corneal edema and Descemet's membrane folds in three eyes, fibrotic exudation in 2, local iris posterior synechia in 1, and transient hypotony in 1, which were resolved spontaneously or with medication. The 25-ga PPV procedure seems to be safe and effective for treating malignant glaucoma. Combined vitrectomy with phacoemulsification surgery and a staged surgical approach may improve the success rate.

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.

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.

Comparative evaluation of 23- and 25-gauge microincision vitrectomy surgery in management of diabetic macular traction retinal detachment

PURPOSE

To compare the efficacy, outcomes, and complications of 23-G and 25-G microincision vitrectomy surgery (MIVS) in cases of diabetic tractional retinal detachment (TRD).

METHODS

This is a prospective, single-blinded, randomized, comparative study. Fifty eyes of 50 patients with diabetic TRD involving or threatening macula were randomized into 2 groups of 25 each. Group 1 underwent 23-G MIVS and group 2 underwent 25-G MIVS. Patients were followed up at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year after surgery. The primary outcome measure was anatomic and visual success after surgery. We also compared the 2 alternative MIVS systems and assessed various intraoperative and postoperative parameters.

RESULTS

Anatomic achievement was achieved in all eyes and both groups showed a significant improvement in vision after surgery (p = 0.033 and p = 0.004, respectively) and were comparable (p = 0.584). Mean surgical time in 25-G surgery was significantly longer than in 23-G surgery by 4.60 minutes (p<0.001). Postoperative mean astigmatism was comparable in the 2 groups and postoperative hypotony was not encountered in either group. No port-related breaks were seen in either group; however, iatrogenic breaks occurred in 4 eyes in the 23-G group and 5 eyes in the 25-G group (p = 1.000). There was significantly less immediate postoperative pain and foreign body sensation in the 25-G group compared with the 23-G group.

CONCLUSIONS

Both 23-G and 25-G MIVS have comparable visual and anatomic results for diabetic TRD; however, 25-G surgery may be associated with less postoperative pain and discomfort than 23-G surgery.

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.

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.