BRILLIANT BLUE G-ASSISTED INTERNAL LIMITING MEMBRANE PEELING FOR MACULAR HOLE: A Systematic Review of Literature and Meta-Analysis

Features of a well-timed macular hole closure related retinal regmatogenous detachment complicated by macular hole

The literature review deals with the analysis of the timing and surgical techniques of macular hole closure in patients with retinal detachment complicated by macular hole. Modern concepts of treatment tactics for this disease, its efficacy are analyzed. Benefits and drawbacks of each of the discussed surgical treatment methods are specified.

Electroretinographic Assessments of Macular Function after Brilliant Blue G Staining for Inner Limiting Membrane Peeling

Purpose: The purpose of this study was to determine the effect of brilliant blue G (BBG) staining of the inner limiting membrane (ILM) on macular function. Method: Fourteen eyes of 14 patients consisting of 9 men and 5 women who underwent vitreous surgery with ILM peeling were studied. The mean age of the patients was 68.8 ± 9.14 years. Three eyes had a macular hole and eleven eyes had an epiretinal membrane. The ILM was made more visible by spraying 0.25% BBG into the vitreous cavity. The macular function was assessed by recording intraoperative focal macular electroretinograms (iFMERGs) before and after the intravitreal spraying of the BBG dye. The iFMERGs were recorded three times after core vitrectomy. The first recording was performed before the BBG injection (Phase 1, baseline), the second recording was performed after the spraying of the BBG and washing out the excess BBG (Phase 2), and the third recording was performed after the ILM peeling (Phase 3). All recordings were performed after 5 min of light-adaptation and stabilization of the intraocular conditions. The iFMERGs were recorded twice at each phase. The implicit times and amplitudes of the a- and b-wave, the PhNR, and the d-wave were measured. Wilcoxon signed-rank test were used to determine the significance of differences of the findings at Phase 2 vs. Phase 1 and Phase 3 vs. Phase 1. A p value < 0.05 was taken to be statistically significant. Results: The average implicit times of the a-wave, b-wave, PhNR, and d-wave were not significantly different in Phase 1, 2, and 3. The average a-wave, b-wave, PhNR, and d-wave amplitudes at Phase 1 did not differ significantly from that at Phase 2 and at Phase 3. Conclusions: The results indicated that the intravitreal injection of BBG does not alter the physiology of the macula, and we conclude that BBG is safe. We also conclude that iFMERGs can be used to monitor the macular function safely during intraocular surgery.

Internal limiting membrane peeling in macular hole surgery

Since the era when macular hole was considered untreatable, macular hole surgery has come a long way to being one of the most successful surgeries. Internal limiting membrane (ILM) peeling has been an essential step of macular hole surgery since the establishment of the role of ILM in the aetiopathogenesis and progression of macular hole. However, the novel technique was not all virtuous. It had some vices which were not evident immediately. With the advent of spectral domain optical coherence tomography, short- and long-term effects of ILM peeling on macular structures were known; and with microperimetry, its effect on the function of macula could be evaluated. The technique has evolved with time from total peeling to inverted flap to just temporal peeling and temporal flap in an attempt to mitigate its adverse effects and to improve its surgical outcome. ILM abrasion technique and Ocriplasmin may eliminate the need of ILM peeling in selected cases, but they have their own limitations. We here discuss the role of ILM in the pathogenesis of macular hole, the benefits and adverse effects of ILM peeling, and the various modifications of the procedure, to then explore the alternatives.

Factors Associated with Anatomic Failure and Hole Reopening after Macular Hole Surgery

A macular hole (MH), particularly an idiopathic macular hole (IMH), is a common cause of central vision loss. Risk factors for nonidiopathic MH include high myopia, cystoid macular edema, inflammation, and trauma. MH is primarily diagnosed using slit-lamp microscopy and optical coherence tomography (OCT). Half of the patients with stage I MHs are treated conservatively and may show spontaneous resolution. The main treatment methods for MHs currently include vitrectomy and stripping of the internal limiting membrane (ILM). However, in some patients, surgery does not lead to anatomical closure. In this review, we summarize the factors influencing the anatomical closure of MHs and analyze the potential underlying mechanisms.

Long-Term Outcomes of Macular Hole Repair with Triamcinolone Acetonide Visualization

Purpose

To evaluate the long-term anatomic and visual outcomes of macular hole (MH) repair utilizing triamcinolone acetonide (TA) visualization of the internal limiting membrane (ILM) treated at a tertiary care retina practice.

Methods

Retrospective chart review of eyes undergoing MH repair with ILM peel utilizing TA visualization followed by gas tamponade and facedown positioning between 2014 and 2020. Pre- and post-operative visual acuity (VA), IOP, and anatomic closure based on optical coherence tomography were documented.

Results

Seventy-eight eyes were followed for 2.3±0.2 years after primary repair with anatomic closure in 73 (94%) eyes at their final visit and excluding eyes with pathologic myopia, 97%, and for stage 2 and small MHs, 100%. In all eyes, VA significantly improved from 0.97±0.04 (Snellen: 20/187) to 0.66±0.06 (20/91) logMAR (p < 0.0001). There were 16 eyes with 4 years of follow-up, 10 (63%) eyes achieving a VA ≥20/30 at that follow-up visit. Stage 2 and 3 MHs had significantly greater improvements in VA than Stage 4 MHs, −0.46 ± 0.06 versus −0.11 ± 0.11 logMAR (p = 0.021). Of the 13 (17%) eyes with recurrent MHs, 6 (46%) had pathologic myopia and 8 (61.5%) had associated cystoid macular edema. Cataract progression was reported in 52 (96%) phakic eyes and 2 eyes required Ahmed valve placement for management of pre-existing glaucoma.

Conclusion

Long-term results of MH repair with TA for ILM visualization demonstrate that it is safe and effective. Visual acuity continued to improve throughout the follow-up. Pre-existing glaucoma may progress and recurrence is associated with pathologic myopia and macular edema.

Efficacy of different doses of dye-assisted internal limiting membrane peeling in idiopathic macular hole: a systematic review and network meta-analysis

PURPOSE

Pars plana vitrectomy is the gold standard for the treatment of idiopathic macular hole. Several chromovitrectomy dyes have been used to improve the visualization of the internal limiting membrane (ILM), including indocyanine green, trypan blue (TB), brilliant blue G (BBG), and triamcinolone acetonide (TA). We conducted a network meta-analysis (NMA) to establish the optimum concentration of chromovitrectomy dye-assisted ILM peeling for IMH.

METHODS

We searched PubMed, Embase, and Cochrane Library for relevant studies before January 2020. We performed a random-effects NMA using STATA version 15.1 to assess mean difference and odds ratios with 95% confidence intervals.

RESULTS

We identified twelve retrospective trails and five randomized controlled trials (RCTs), comprising 1 492 patients of IMH on stage II-IV for ILM peeling. The results of IMH closure rate show that the effect of ILM peeling without dye was better than 0.25% ICG, the effects of ILM peeling with 0.5% ICG or TA were better than without dye, and the effects of ILM peeling with 0.05% BBG, 0.15% TB, 0.5% ICG or 0.05% ICG were better than 0.25% ICG. Ranking probability analysis shows that the rates of IMH closure after ILM peeling with 0.15% TB or 0.05% BBG were better than nine other concentrations of chromovitrectomy dyes.

CONCLUSION

The 0.15% TB and 0.05% BBG were recommended as the better efficient treatment-assisted ILM peeling for IMH closure. For retina specialists who prefer to use ICG to assist ILM peeling, 0.05% ICG may be a good choice. However, high-quality large-scale RCTs are recommended to confirm the NMA results.

Outcomes of Idiopathic Full-Thickness Macular Hole Surgery: Comparing Two Different ILM Peeling Sizes

Purpose

This study aimed to show the impact of different extents of internal limiting membrane (ILM) peeling on visual and anatomical outcomes following idiopathic full-thickness macular hole (FTMH) surgery.

Methods

In this single-center prospective study, patients with idiopathic FTMH underwent standard pars plana vitrectomy with two different extents of ILM peeling: 2-disc diameters (DD) or 4 DD. The main outcome measures were the closure rate of the holes based on optical coherence tomography (OCT) findings at three months after surgery.

Results

Forty eyes from 39 patients were enrolled in the study. After three months, anatomical closure was achieved in 78% and 76% eyes in 2 DD peel and 4 DD peel groups, respectively. From 29 eyes with macular hole index (MHI) ≤ 0.5, type 1 closure was achieved in 42% eyes receiving a 2 DD ILM peel, compared to 66% eyes receiving a 4 DD peel (p=0.041). In comparison, this significant difference was not seen in the subgroup of MHI > 0.5 (p=061). In the subgroup of subjects with baseline MHI ≤ 0.5, visual improvement was significantly more in eyes with 4 DD ILM peeling (p=0.034), which was not seen in the MHI > 0.5 subgroup (p=0.61).

Conclusion

In patients with idiopathic full‐thickness macular hole (MHI ≤ 0.5), a larger ILM peel of 4 DD appears to yield better anatomical outcomes than a more limited 2 DD peel.

Internal limiting membrane flap technique in macular hole surgery

Vitrectomy combined with internal limiting membrane (ILM) peeling is popular for the treatment of macular hole (MH). However, the improvements of MH closure rate and postoperative visual acuity are not satisfactory especially in large and refractory MHs. Currently, the ILM flap technique has gradually been applied for the treatment of MH and achieved high MH closure rate. The ILM flap technique has many variations, including the difference of the size, shape, number, and manner in which the flaps put on the MHs. The ILM flap technique also has some auxiliary means including perfluoro-n-octane (PFO), dye, autologous blood and adhesive viscoelastics. There is controversy about the effects between several technique variations of ILM flap, and it needs to be explored in the future.

Outcomes of 4 surgical adjuvants used for internal limiting membrane peeling in macular hole surgery: a systematic review and network Meta-analysis

AIM

To compare the outcomes of four adjuvants used for internal limiting membrane (ILM) peeling in macular hole surgery, including indocyanine green (ICG), brilliant blue G (BBG), triamcinolone (TA) and trypan blue (TB), through systematic review and random-effects Bayesian network Meta-analysis.

METHODS

PubMed, Cochrane library databases and Web of Science were searched until August 2018 for clinical trials comparing the above four adjuvants. ORs for postoperative best corrected visual acuity (BCVA) improvement and primary macular hole closure rates were compared between the different adjuvants.

RESULTS

Twenty-seven eligible articles were included. For postoperative BCVA improvement, results of BBG-assisted peeling were significantly more favorable than those of ICG (WMD 0.08, 95% credible interval 0.01-0.16) and TA ranked highest. No significant differences were found between any other two groups in postoperative BCVA improvement. For postoperative primary macular hole closure rates, BBG ranked highest. However, no significant differences were shown between any two groups.

CONCLUSION

TA and BBG are the optimum adjuvants for achieving postoperative BCVA improvement macular hole surgery with adjuvant-assisted ILM peeling. Among all adjuvants, the use of BBG is associated with the highest postoperative macular hole closure rate.

Outcome of autologous platelet concentrate and gas tamponade compared to heavy silicone oil tamponade in persistent macular hole surgery

PURPOSE

Persistence represents the major reason for failure of primary macular hole repair. A variety of surgical approaches are available for treating persistent macular holes. To compare clinical outcome of re-pars plana vitrectomy combined with autologous platelet concentrate and sulfur hexafluoride 20% gas tamponade with heavy silicone oil in persistent macular hole.

METHODS

Records of 48 consecutive eyes with persistent macular holes which underwent re-pars plana vitrectomy with either heavy silicone oil (35 eyes, persistent macular-hole minimum linear diameter: 518.8 ± 171.1 µm) or autologous platelet concentrate and sulfur hexafluoride 20% (13 eyes, persistent macular hole-minimum linear diameter: 454.1 ± 211.3 µm) were reviewed retrospectively. All patients underwent measurements of anatomical persistent macular hole characteristics evaluated by optical coherence tomography and visual function. Cases in which anatomical success failed after first re-pars plana vitrectomy were treated with the other surgical techniques, comparable to a cross-over design.

RESULTS

Persistent macular hole closure rate was 57.1% with autologous platelet concentrate and sulfur hexafluoride 20% and 45.7% with heavy silicone oil (p = 0.102). Functional results were comparable when persistent macular hole closure was achieved (p ⩾ 0.741), but significantly better for the autologous platelet concentrate with sulfur hexafluoride 20% group when persistent macular hole closure failed (p = 0.019).

CONCLUSION

Re-pars plana vitrectomy combined with autologous platelet concentrate and sulfur hexafluoride 20% seems to achieve at least non-inferior persistent macular hole closure rates and comparable functional results when compared to heavy silicone oil, suggesting autologous platelet concentrate and sulfur hexafluoride 20% as a safe surgical alternative in persistent macular hole. Especially when persistent macular hole closure failed, autologous platelet concentrate with sulfur hexafluoride 20% seems to be superior regarding visual outcome.

Internal limiting membrane peeling with different dyes in the surgery of idiopathic macular hole: a systematic review of literature and network Meta-analysis

AIM

To evaluate the effect of internal limiting membrane (ILM) peeling with indocyanine green (ICG), brilliant blue G (BBG), triamcinolone acetonide (TA), trypan blue (TB), or without dye for the treatment of idiopathic macular hole (IMH).

METHODS

A search was conducted using PubMed, EMBASE, and CENTRAL (Cochrane Central Register of Controlled Trials) for related studies published before October 2018.

RESULTS

A total of 29 studies and 2514 eyes were included in this network Meta-analysis. For IMH closure, the rank from the best to the worse treatment was: BBG, TB, TA, ICG, and no dye. There was a significant difference in postoperative IMH closure rate between BBG and no dye. The rank of the best to the worse treatment to improve visual acuity was: BBG, TB, no dye, TA, and ICG. The improvement rate of visual acuity after using BBG was significantly higher than ICG. The improvement rate of visual acuity was more favorable with TB than ICG, TA, and no dye.

CONCLUSION

BBG can contribute to better anatomical and functional outcomes compared to other dyes for ILM peeling in patients with IMH. The results show that the best treatment of ILM peeling with dyes is BBG.

[Effect of Dyes Containing Lutein on Enhanced Visibility of Epiretinal Pathologies in Intraoperative OCT]

BACKGROUND

Epiretinal membranes are a disorder leading to metamorphopsia and loss in visual function. The gold standard in therapy is vitrectomy with membrane peeling, usually performed with chromovitrectomy. The aim of this study was to examine whether dyes containing lutein are capable of enhancing visualization of epiretinal tissue in intraoperative optical coherence tomography (iOCT).

PATIENTS AND METHODS

This was a prospective study that included 20 eyes of 20 patients with idiopathic epiretinal membranes scheduled for surgery. 23 G pars plana vitrectomy with intraoperative assistance of iOCT was performed in all cases. Staining of epiretinal membranes was performed with dyes containing trypan blue, brilliant blue G and lutein (tripledyne and dualdyne, both Kemin Industries Inc., USA).

RESULTS

In all patients (n = 20), staining of epiretinal tissue was good, and crystalline lutein particles could be well depicted in iOCT compared to soluble lutein that does not enhance visualisation of epiretinal tissue in iOCT.

CONCLUSIONS

The addition of lutein to commonly used dye formulations offers good staining properties and, in case of crystalline lutein, also enhances epiretinal tissue in iOCT.

Alterations of Foveal Architecture during Vitrectomy for Myopic Retinoschisis Identified by Intraoperative Optical Coherence Tomography

PURPOSE

To determine the changes in the foveal architecture before and after internal limiting membrane (ILM) peeling with and without fovea-sparing ILM peeling (FSIP) during vitrectomy for high myopic retinoschisis by intraoperative optical coherence tomography (iOCT).

METHODS

Qualitative assessments were made of the alterations of the retinal architecture imaged by iOCT following complete ILM peeling (peeled group) or fovea-sparing ILM peeling (FSIP group). A microscope-integrated real-time iOCT device was used to analyze the retinal architectures. The alterations included a worsening of the retinoschisis, development of a foveal detachment, and development of a full thickness macular hole. The changes in the retinal architecture, clinical characteristics, and outcomes were compared between the 2 groups.

RESULTS

The medical records of 15 eyes of 15 patients were studied. Complete ILM peeling was performed on 9 of 15 eyes, and 8 of the 9 eyes (89%) showed a worsening of the retinal architectures following the ILM peeling. FSIP was performed on 6 of the 15 eyes, and none of these eyes developed any retinal architectural changes in the iOCT images. The mean postoperative best-corrected visual acuity (BCVA) in eyes that underwent FSIP (20/38) was significantly better than that of preoperative BCVA (20/128; p < 0.05), although the differences in the preoperative BCVA (20/87) and postoperative BCVA (20/55) in the cases that underwent complete ILM peeling were not significant.

CONCLUSIONS

The lack of alterations of the foveal architecture and significant improvements in the BCVA after FSIP indicate that FSIP peeling should be considered for eyes with retinoschisis. We recommend that iOCT be used to monitor the retinal architecture during intraocular surgery involving the retina.

Anterior chamber aqueous flare is not a predictor for surgical closure of full-thickness idiopathic macular holes

Purpose:

To investigate the predictive value of preoperative anterior chamber aqueous flare levels measured by laser flare photometry for surgical success of idiopathic macular holes in addition to preoperative anatomic characteristics.

Methods:

Records of 105 consecutive eyes with full-thickness idiopathic macular holes which underwent pars plana vitrectomy with internal limiting membrane peeling and sulfur hexafluoride 20% (SF620%) endotamponade were reviewed retrospectively. All patients underwent preoperative measurements of anterior chamber aqueous flare and anatomical idiopathic macular hole characteristics evaluated by optical coherence tomography: macular hole inner opening diameter, macular hole minimum linear diameter, macular hole base diameter, and macular hole height. Best-corrected visual acuity results were recorded pre- and postoperatively.

Results:

In 17 (16.2%) of 105 eyes primary closure of idiopathic macular hole failed, whereas in 88 eyes (83.8%) closure was achieved. Between both groups, preoperative macular hole minimum linear diameter (p = 0.001) and macular hole inner opening diameter (p = 0.006) were statistically different. Failure rates were significantly lower in eyes with macular hole minimum linear diameter < 400 µm (7.4% vs 32.4%; p = 0.013) and preoperative macular hole minimum linear diameter showed moderate correlation with pre- and postoperative best-corrected visual acuity results (r = 0.512; p < 0.001; r = 0.612; p < 0.001). Mean anterior chamber aqueous flare of 11.5 ± 9.9 pc/ms in eyes with anatomical closure and 11.8 ± 6.4 pc/ms in unclosed cases was comparable (p = 0.28) and did not correlate with anatomical or functional results.

Conclusion:

Eyes with idiopathic macular hole ⩾ 400 µm in size have a significantly higher failure rate following standardized pars plana vitrectomy with internal limiting membrane peeling and SF620% endotamponade. Preoperative macular hole minimum linear diameter and macular hole inner opening diameter seem to be associated with surgical outcome in idiopathic macular hole, whereas anterior chamber aqueous flare level does not provide additional predictive value.

Vital Dyes in Vitreomacular Surgery

Vital dyes contain complex molecules with chromophores that stain living tissues and have greatly enhanced identification and removal of transparent vitreoretinal tissues during surgery. Several "chromovitrectomy" dyes are frequently used by vitreoretinal specialists, including indocyanine green, trypan blue, brilliant blue G, and triamcinolone acetonide; other dyes are also under investigation. Trypan Blue was approved by the U.S. Food and Drug Administration (FDA) for epiretinal membrane removal, and preservative-free triamcinolone acetonide was approved by the FDA for intraocular use. However, currently available chromovitrectomy dyes have their limitations, and of particular concern for some of them is the possibility for acute and chronic toxicity to the neurosensory retina and retinal pigmented epithelium. The potentially irreversible acute toxicity and other limitations, such as lack of long-term safety profiles, highlight the need for further advancements. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:788-798.].

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.

Non-inverted pedicle internal limiting membrane transposition for large macular holes

PURPOSE

The purpose of this study is to investigate the effectiveness of a new surgical technique of non-inverted pedicle internal limiting membrane (ILM) transposition for the treatment of eyes with large macular hole.

METHODS

This is a retrospective, consecutive, interventional case series. Twelve eyes of 12 consecutive patients who underwent vitrectomy for the treatment of a large macular hole (MH size > 400 µm) were treated. ILM was peeled and left with a pedicle attached to the superior temporal retina. The macular hole was covered by transposition of the pedicle ILM in a non-inverted way. Preoperative and postoperative best-corrected visual acuity (BCVA), SD-OCT image, macular sensitivity by microperimetry, and multifocal electroretinogram (mERG) response were evaluated. All of the patients were followed for more than 3 months.

RESULTS

Postoperative OCT examination confirmed 11 of 12 macular hole closed (91.7%). Six macular hole filled with silicone oil closed as early as the next day. The postoperative BCVA significantly increased compared with preoperative BCVA (P = 0.002). The improvement of macular sensitivity within 2° and 8° circle was also statistical significant (P = 0.018 and P = 0.017, respectively). Fixation stability, shown as the percentage of fixation point within the 2° circle and 4° circle, was remarkably improved (P = 0.017 and P = 0.018, respectively). The R1/R2 and R1/R4 ring ratios also increased significantly as compared with that of baseline.

CONCLUSION

These findings indicate that the non-inverted pedicle ILM transposition results in a high incidence of anatomic closure with good visual outcome for the treatment of large macular hole.

EFFECTS OF INTERNAL LIMITING MEMBRANE PEELING COMBINED WITH REMOVAL OF IDIOPATHIC EPIRETINAL MEMBRANE: A Systematic Review of Literature and Meta-Analysis

PURPOSE

To evaluate the effects on postoperative prognosis of internal limiting membrane (ILM) peeling in conjunction with removal of idiopathic epiretinal membranes (ERMs).

METHODS

MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were systematically searched for studies that compared ILM peeling with no ILM peeling in surgery to remove idiopathic ERM. Outcome measures were best-corrected visual acuity, central macular thickness, and ERM recurrence. Studies that compared ILM peeling with no ILM peeling for the treatment of idiopathic ERM were selected.

RESULTS

Sixteen studies that included 1,286 eyes were selected. All the included studies were retrospective or prospective comparative studies; no randomized controlled study was identified. Baseline preoperative best-corrected visual acuity and central macular thickness were equal between ILM peeling and no ILM peeling groups. Postoperatively, there was no statistically significant difference in best-corrected visual acuity (mean difference 0.01 logarithm of the minimum angle of resolution [equivalent to 0.5 Early Treatment Diabetic Retinopathy Study letter]; 95% CI -0.05 to 0.07 [-3.5 to 2.5 Early Treatment Diabetic Retinopathy Study letters]; P = 0.83) or central macular thickness (mean difference 13.13 μm; 95% CI -10.66 to 36.93; P = 0.28). However, the recurrence rate of ERM was significantly lower with ILM peeling than with no ILM peeling (odds ratio 0.25; 95% CI 0.12-0.49; P < 0.0001).

CONCLUSION

Currently available evidence in the literature indicates that additional ILM peeling in vitrectomy for idiopathic ERM could result in a significantly lower ERM recurrence rate, but it does not significantly influence postoperative best-corrected visual acuity and central macular thickness.

Antipurinergic therapy for autism-An in-depth review

Are the symptoms of autism caused by a treatable metabolic syndrome that traces to the abnormal persistence of a normal, alternative functional state of mitochondria? A small clinical trial published in 2017 suggests this is possible. Based on a new unifying theory of pathogenesis for autism called the cell danger response (CDR) hypothesis, this study of 10 boys, ages 5-14years, showed that all 5 boys who received antipurinergic therapy (APT) with a single intravenous dose of suramin experienced improvements in all the core symptoms of autism that lasted for 5-8weeks. Language, social interaction, restricted interests, and repetitive movements all improved. Two children who were non-verbal spoke their first sentences. None of these improvements were observed in the placebo group. Larger and longer studies are needed to confirm this promising discovery. This review introduces the concept of M2 (anti-inflammatory) and M1 (pro-inflammatory) mitochondria that are polarized along a functional continuum according to cell stress. The pathophysiology of the CDR, the complementary functions of M1 and M2 mitochondria, relevant gene-environment interactions, and the metabolic underpinnings of behavior are discussed as foundation stones for understanding the improvements in ASD behaviors produced by antipurinergic therapy in this small clinical trial.