Epiretinal Membrane Surgery Using Intraoperative OCT-Guided Membrane Removal in the DISCOVER Study versus Conventional Membrane Removal

PURPOSE

To provide a comparative assessment of clinical outcomes between patients undergoing intraoperative OCT (iOCT) and conventional surgery for pars plana vitrectomy (PPV) with epiretinal membrane (ERM) peel.

DESIGN

Case-control retrospective, comparative assessment.

PARTICIPANTS

Patients undergoing PPV with membrane peel for ERM with eyes pooled from the prospective Determination of Feasibility of Intraoperative Spectral Domain Microscope Combined/Integrated OCT Visualization During En Face Retinal and Ophthalmic Surgery (DISCOVER) iOCT study and eyes undergoing conventional ERM surgery without iOCT.

METHODS

Visual acuity and OCT assessment before ERM surgery and at 1-, 3-, 6-, and 12-month follow-up after standard small-gauge PPV with iOCT feedback (iOCT DISCOVER group) or PPV with compulsory internal limiting membrane (ILM) peeling (conventional group). Visual acuity, central subfield thickness (CST), reoperation rate, and ERM recurrence were determined by record review and post hoc assessment of clinical OCTs after ERM peel.

MAIN OUTCOME MEASURES

Visual acuity and ERM recurrence.

RESULTS

A total of 262 eyes were included. Visual acuity (VA) improved 11.9 letters in the iOCT group (P < 0.0001) and 12.1 letters in the conventional group (P < 0.0001) at 12 months after ERM surgery. Visual acuity improvement did not differ between the iOCT and conventional groups at 1, 3, 6, or 12 months after surgery (P > 0.05 for each time point). Preoperative mean CST decreased in the iOCT group (P < 0.0001) and conventional group (P < 0.0001) with no difference between groups in CST reduction at 12 months (P = 0.36). No reoperations or visually significant recurrent ERMs occurred in either cohort.

CONCLUSIONS

Intraoperative OCT-guided ERM removal without mandated ILM peeling provided similar VA and anatomic results to conventional ILM peeling for ERM. Future randomized prospective studies are needed to assess fully the possible role of iOCT in ERM surgery and to evaluate the potential impact of nonfoveal ERM persistence or recurrence in comparison with conventional surgery.

iOCT-assisted macular hole surgery: outcomes and utility from the DISCOVER study

BACKGROUND/AIMS

This study aimed to characterise the clinical outcomes and utility of intraoperative optical coherence tomography (iOCT)-assisted macular hole (MH) repair.

METHODS

This was a post hoc analysis of eyes in the D etermination of feasibility of I ntraoperative S pectral domain microscope C ombined/integrated O CT V isualization during E n face R etinal and ophthalmic surgery (DISCOVER) study undergoing surgical MH repair with use of iOCT. Functional and surgical outcome data were collected through 12 months postoperatively. MH closure rate, postoperative visual acuity (VA), percentage of cases in which iOCT provided valuable feedback and altered surgical decision making were measured.

RESULTS

Eighty-four eyes were included in this study. The mean preoperative VA measured 20/114. The mean postoperative VA improved to 20/68 (p<0.001) at month 1, 20/48 (p<0.001) at month 3 and 20/45 (p<0.001) at month 12 or later. In 43 cases (51%), surgeons reported that iOCT provided valuable information (eg, confirming release of vitreomacular traction and identification of occult residual membranes). In 10 cases (12%), iOCT data specifically altered surgical decision making. Postoperative day 1 transtamponade OCT confirmed tissue apposition and apparent hole closure in 74% of eyes (21/26). All five open holes on postoperative day 1 closed following positioning. Single-surgery MH closure was achieved in 97.6% of cases. One persistent MH was successfully closed with a subsequent surgical repair for a final overall closure rate of 98.8%. Due to chronicity and MH size, additional repair was not recommended for the single remaining persistent MH.

CONCLUSION

This study suggests that iOCT may have important utility in MH surgery, including impacting surgical decision making. iOCT-assisted MH surgery resulted in significant improvement in VA and high single-surgery success rate.

TO PEEL OR NOT TO PEEL THE INTERNAL LIMITING MEMBRANE IN IDIOPATHIC EPIRETINAL MEMBRANES

BACKGROUND

Epiretinal membranes (ERMs) have been described for more than 150 years. Currently, they are a common indication for vitreoretinal surgery. Recently, there has been an increasing trend to peel the internal limiting membrane (ILM). Although ILM peeling has generally been accepted as a fundamental step in macular hole repair, its current role in ERM remains controversial.

METHODS

Literature review.

RESULTS

Proponents of ILM peeling argue that peeling of the ILM reduces the recurrence rate and facilitates a greater resolution of retinal folds. Opponents of ILM peeling show that the visual outcomes between eyes that undergo ILM peeling and those that do not have their ILM peeled are the same. Stripping of the ILM removes the Müller cell footplates, so it is reasonable to expect some Müller cell dysfunction. Adverse events such as eccentric paracentral macular holes, macular microscotomata, and retinal dimpling have been associated with ILM peeling.

CONCLUSION

Internal limiting membrane peeling does not improve the functional outcomes after ERM surgery. Internal limiting membrane peeling reduces ERM recurrences, but many recurrences are not clinically significant. It remains unclear what the long-term effects of ILM peeling are. We should err on the side of caution and avoid routine ILM peeling in primary idiopathic ERM cases and should reserve it for recurrent and high risk of recurrence cases.

A Review of Surgical Outcomes and Advances for Macular Holes

The surgical outcomes of macular holes (MHs) have improved greatly in recent years. The closure rate is as high as 90-100%, but the outcomes of some special types of MHs remain unsatisfactory. Internal limiting membrane (ILM) peeling dramatically improves the anatomic success rate, but recent studies have found that it could also cause mechanical and subclinical traumatic changes to the retina. Dyes are widely used, and apart from indocyanine green (ICG), the toxicities of other dyes require further research. Face-down posturing is necessary for MHs larger than 400 μm, and the duration of this posture is determined by the type of tamponade and the case. The ellipsoid zone has been shown to be highly correlated with visual outcome and recovery. New surgical methods include the inverted ILM flap technique and the ILM abrasion technique. However, they require further research to determine their effectiveness.

[Idiopathic macular hole: history and status quo review]

The article reviews the literature on one of the topical problems of vitreoretinal surgery - idiopathic macular holes. The history, concept, classification and diagnostics, as well as surgical and alternative treatment methods of macular holes are explored.

A review of current management of vitreomacular traction and macular hole

The paper presents a review of the sequence of events of posterior vitreous detachment (PVD), vitreomacular adhesion (VMA), vitreomacular traction (VMT), and macular hole (MH) from their pathophysiological aspects, clinical features, diagnostic implications, and current management strategies. A treatment algorithm to be used in clinical practice in patients with VMA, VMT, and MH based on the presence of symptoms, visual acuity, associated epiretinal membrane, and width of the vitreous attachment is presented. Observation, pharmacologic vitreolysis with ocriplasmin, and surgical treatment are positioned as treatment options in the different steps of the therapeutic algorithm, with clear indications of the paths to be followed according to the initial presenting manifestations and the patient's clinical course.

Predicting visual outcome following surgery for idiopathic macular holes

Since Kelly and Wendel [Arch Ophthalmol 1991;109:654-659] first reported successfully treating macular holes (MHs) using pars plana vitrectomy in 1991, MH surgery has been constantly improved. For example, introducing the removal of the internal limiting membrane considerably increased the closure rate of MHs, and the advent of microincision vitrectomy surgery reduced surgical trauma and decreased patient discomfort after surgery. As modern MH surgery can achieve a higher anatomical success rate and alleviate patients' postoperative distress, postoperative visual outcomes have lately become the primary concern. Informing patients of the expected visual acuity and visual improvement before surgery is ideal, but predicting postoperative visual outcomes is difficult because a large number of factors are associated with them. In this paper, we review previous studies and provide accumulating evidence for the relationship between individual prognostic factors and visual outcomes after MH surgery.

Effects of indocyanine green staining on the recovery of visual acuity and macular morphology after macular hole surgery

PURPOSE

To evaluate whether indocyanine green (ICG)-assisted internal limiting membrane peeling affects visual outcome and macular morphologic changes in spectral-domain optical coherence tomography images after macular hole (MH) surgery.

METHODS

A retrospective analysis was performed of 34 eyes in 34 patients who had undergone surgical treatment for MH. Best-corrected visual acuity (BCVA) and optical coherence tomography parameters including central foveal thickness, length of the external limiting membrane (ELM) defect, and length of the inner segment and outer segment (IS/OS) defect were analyzed pre- and postoperatively.

RESULTS

The eyes were divided into 2 groups based on ICG use (ICG+/-). The changes in BCVA did not differ significantly between the 2 groups at 6 months. However, the ICG+ group had poorer changes compared with the ICG- group at 1 and 3 months (p = 0.038, p = 0.012, respectively). Central foveal thickness and ELM defect did not differ between the 2 groups at each period. The IS/OS defect in the ICG+ group was significantly greater at 1 and 3 months than that in the ICG- group (p = 0.026, p = 0.048, respectively).

CONCLUSIONS

ICG staining may affect the recovery process of macular morphology and visual acuity in the first several months after MH surgery.

The structural effect of intravitreal Brilliant blue G and Indocyanine green in rats eyes

PURPOSE

To compare the potential retinal toxicity of two commercially Brilliant blue G dyes (Brilliant Peel and Ocublue Plus) and Indocyanine green (ICG) at usual clinical concentration.

METHODS

Brilliant Peel 0.025% (n=9), Ocublue Plus 0.025% (n=9), and ICG 0.05% (n=9) were injected intravitreally into Sprague-Dawley rat left eyes with balanced salt solution injected in the contralateral eyes as control. Evaluation of the effect of the dyes on retinal architecture was done by histological analysis of neurosensory retinal thickness and retinal ganglion cell (RGC) counts 7 days after intravitreal injection. Paired t-test was done to detect the presence of biologically significant thinning in neurosensory retina and five retinal layers for each dye (paired t-tests). One-way ANOVA and Tukey's Honestly Significant Difference test were used to assess whether different dyes caused significant thinning in mean neurosensory retinal thickness and reduction of mean RGC density.

RESULTS

Eyes treated with ICG had significantly thinner mean total neurosensory retinal thickness compared with the control eyes (P-value=0.01), followed by those treated with Ocublue Plus (P-value=0.03). Brilliant Peel did not cause significant thinning in any of the five retinal layers (all P-values>0.05). No significant difference in mean thinning of the total retinal thickness was detected between dyes (P-value=0.11). The mean thickness of the photoreceptor outer segment and outer plexiform layers were significantly reduced in ICG-injected eyes when compared with the control eyes (P-value=0.02). No significant difference in mean thinning between the three dyes was detected at all five retinal layers using one-way ANOVA (all P-values>0.35). RGC density was significantly reduced for ICG (P-value=0.01) but only marginally for Ocublue Plus (P-value=0.05). No significant reduction in RGC density was observed for Brilliant Peel (P-value=0.2).

CONCLUSION

Intravitreal Brilliant Peel is safe to rats retina. The retinal thinning and reduction in RGC density induced by Ocublue Plus requires further studies to determine the safety profile of this product. Potential retinal toxicity is seen with ICG 0.05%.

Indocyanine green-assisted internal limiting membrane peeling in macular hole surgery: a meta-analysis

Background

The opinion of application of indocyanine green (ICG) in the macular hole surgery was contradictory. Here we conducted a meta-analysis to evaluate the effect of in internal limiting membrane (ILM) peeling for macular hole surgery.

Methods and Findings

We searched electronic databases for comparative studies published before July 2012 of ILM peeling with and without ICG. Twenty-two studies including 1585 eyes were included. Visual acuity (VA) improvement, including the postoperative rate of ≥20/40 VA gained (OR, 0.65; 95% CI, 0.43 to 0.97; P = 0.033) and increased LogMAR (WMD, −0.09; 95% CI, −0.16 to −0.02; P = 0.011), was less in the ICG group. The risk of visual field defects was greater in the ICG group than in the non-ICG group. There was no significant difference in the rate of anatomical outcomes between ILM peeling procedures performed with and without ICG. RPE changes and other postoperative complications were not significantly different between the ICG and non-ICG groups. An additional analysis showed that the VA improvement of the ICG group was less than the non-ICG group only within the first year of follow up. A subgroup analysis showed that the rate of VA improvement was lower in the ICG group than in other adjuncts group. A higher rate of secondary closure and less VA improvement were observed in a high proportion (>0.1%) of the ICG group. A sensitivity analysis after the randomized-controlled trials were excluded from the meta-analysis demonstrated no differences compared with the overall results.

Conclusions

This meta-analysis demonstrated that there is no evidence of clinical superiority in outcomes for ICG-assisted ILM peeling procedure over the non-ICG one. The toxicity of ICG should be considered when choosing the various staining methods.

Unanticipated vision loss after pars plana vitrectomy

Although advances in vitreoretinal surgical techniques and technology have helped to minimize the risks associated with surgical manipulation of the retina, retinal pigment epithelium, and optic nerve, unanticipated or unexplained visual loss still occurs. We review causes of vision loss encountered after pars plana vitrectomy, including retinal toxicities, vascular events, and optic neuropathies, and we suggest strategies to limit or prevent them.

Axial length and outcomes of macular hole surgery assessed by spectral-domain optical coherence tomography

PURPOSE

To use spectral-domain optical coherence tomography (SD OCT) to evaluate macular hole surgery outcomes and features predicting anatomic failure.

DESIGN

Retrospective, interventional case series.

METHODS

Fifty-two eyes of 50 consecutive patients with macular holes were examined. All eyes underwent 3-port pars plana vitrectomy with internal limiting membrane peeling. Eyes were examined after surgery by dense serial SD OCT scanning over the macula.

RESULTS

Eyes with initial anatomic failure were significantly more likely to have greater axial length and refractive error and more posterior staphyloma compared with eyes with initial anatomic success (P = .031 to .0060, < .0001). Overall initial and final anatomic success rates were 92.3% (48 of 52 eyes). In highly myopic eyes with axial lengths of 26.0 mm or more, initial and final success rates were 73.3% (11 of 15 eyes) compared with 100.0% (37 of 37 eyes) of eyes with axial lengths of less than 26.0 mm (P = .0050). In highly myopic eyes, initial and final success rates were 0% (0 of 3 eyes) of eyes with axial lengths of 30.0 mm or more compared with 91.7% (11 of 12 eyes) of eyes with axial lengths of 26.0 mm or more and of less than 30.0 mm (P < .0001). Retinoschisis-like thickening of the outer retina was seen in 3 (75.0%) of 4 eyes with initial failure compared with 3 (6.3%) of 48 eyes with initial success (P = .0030).

CONCLUSIONS

Axial length of 30.0 mm or more may increase the risk of anatomic failure of macular hole surgery.

Dyes in ocular surgery: principles for use in chromovitrectomy

PURPOSE

To present the current state-of-the-art information regarding the properties, indications, surgical techniques, and toxic effects of current and past applications of vital dyes in chromovitrectomy.

DESIGN

Critical analysis and surgical perspective of the literature and recent studies.

METHODS

Review, interpretation, and commentary regarding the most relevant experimental as well as clinical studies including the authors' clinical and laboratory research.

RESULTS

There is a consensus that the application of vital dyes facilitates the delicate removal of intraocular membranes during vitreoretinal surgery. Controversy still remains around various issues, mainly potential toxicity and safety. There is room for further investigation of novel and specific vital dyes. Dyes such as Evans blue and light green may stain the internal limiting membrane very well, whereas fast green and indigo carmine may be very safe to the retina. However, comparing the staining and toxicity data has revealed that Bromophenol blue and Brilliant blue may be even better novel agents. The dyes currently used for different steps in chromovitrectomy are: triamcinolone acetonide for vitreous identification; indocyanine green, infracyanine green, and Brilliant blue for internal limiting membrane identification; and Trypan blue for epiretinal membrane identification.

CONCLUSIONS

Clear-cut safety profiles for the different dyes in chromovitrectomy have not yet been established, and current state-of-the-art staining-assisted procedures should be performed using concentrations and volumes as low as possible.