Confirming a MacTel2 diagnosis before treatment: Noah Banoub on common mimics

The FDA approval of revakinagene taroretcel-lwey (Encelto; Neurotech Pharmaceuticals) as the first treatment for macular telangiectasia type 2 (MacTel2) has raised the stakes of an accurate diagnosis before recommending the surgically implanted therapy. Modern Retina spoke with Noah G. Banoub, a third-year medical student (M3) at Kaiser Permanente Bernard J. Tyson School of Medicine with academic interests in ophthalmology, retinal disease and clinical research, about a retrospective review of real-world MacTel2 diagnoses.

In the following Q&A, Banoub discusses how often patients labeled with MacTel2 did not actually meet strict diagnostic criteria, the conditions most often mistaken for it, the imaging findings that most often mislead clinicians, and what a rigorous, confident diagnosis should look like now that an approved treatment exists.

>> Watch the video interview with Robin Vora, MD, who presented these findings at ASRS 2026.

Modern Retina: What prompted this investigation into how patients with macular telangiectasia type 2 are diagnosed in real-world practice, and what emerged from the review of records and multimodal imaging?

Noah G. Banoub: This investigation was prompted by a practical problem: MacTel2 is increasingly important to diagnose correctly because a disease-specific treatment is now available, yet the label is still being applied inconsistently in real-world practice. We wanted to know how often patients coded or documented as having MacTel actually met strict retina-specialist adjudicated criteria, and what was found was a substantial false-positive rate.

After review of records and multimodal imaging, 562 of 754 patients (74.5%) truly had MacTel, while 192 (25.5%) did not. That means more than one in four patients carrying the diagnosis were misclassified, even though many had been labeled by retina specialists, showing that diagnostic error is a real-world issue rather than just a coding problem.

Modern Retina: When a case was ultimately adjudicated as something other than MacTel2, which conditions were most often hiding behind that label, and what did those true diagnoses tend to have in common?

Banoub: When the diagnosis was ultimately something other than MacTel2, the most common hidden conditions were hypertensive retinopathy with perifoveal microaneurysms, retinal vein occlusion, diabetic macular edema or non-proliferative diabetic retinopathy, epiretinal membrane/vitreomacular interface disease, and age-related macular degeneration. Less common mimics included other causes of cystoid macular edema, pattern dystrophy, central serous chorioretinopathy, and toxic maculopathy.

These true diagnoses had one thing in common: they all can create parafoveal structural or vascular changes that overlap with MacTel on OCT, FA, or fundus exam. In other words, the “MacTel look” was often being produced by other retinal diseases that caused cystic spaces, microvascular abnormalities, leakage, or outer retinal distortion.

Modern Retina: Were there specific imaging or examination features that repeatedly steered clinicians toward a MacTel2 diagnosis when the correct answer was something else? Which findings warrant more skepticism?

Banoub: Several imaging and exam findings repeatedly pushed clinicians toward MacTel when the true diagnosis was something else. The biggest offenders were cystoid changes on OCT and telangiectatic-appearing changes, followed by microaneurysms on fundus exam, temporal fluorescein leakage, and retinal hemorrhages. Among these, the findings that warrant the most skepticism are isolated temporal telangiectatic vessels/microaneurysms and cystic spaces on OCT that improve over time or occur alongside traction, vascular leakage, diabetes, hypertension, or other competing explanations.

The key message is that no single feature should be treated as diagnostic on its own. We caution that temporal telangiectatic vessels or microaneurysms alone are not enough for a firm diagnosis, and cystic spaces should prompt a broader differential rather than automatic attribution to MacTel.

Modern Retina: Understanding what drives MacTel2 at the cellular level has shifted considerably over the past decade. What is the current thinking on the underlying disease mechanism, and how has that reshaped the way the condition is classified?

Banoub: The current thinking is that MacTel2 is primarily a neurodegenerative disease driven by Müller cell dysfunction, with the vascular changes being secondary rather than the root cause. Over time, this has shifted the conceptual model away from a purely vascular disorder and toward a disease caused by failure of the retina’s support cells leading to photoreceptor and macular degeneration.

That change matters because it reframes MacTel not just as “telangiectasia” but as a central retinal neurodegeneration with characteristic vascular and pigmentary manifestations. The name can still mislead clinicians into over-weighting the vascular findings, which may partly explain why misdiagnosis happens so often.

Modern Retina: What does a rigorous, confident MacTel2 diagnosis look like? Which components of the multimodal imaging workup do the heaviest lifting, and where are corners most often cut?

Banoub: A confident MacTel2 diagnosis is built on multimodal imaging plus clinical context, not on a single sign. The heaviest-lifting components are the classic OCT findings: loss of foveal contour, inner retinal cavitations with ILM draping, and ellipsoid zone disruption. This then should be supported by FAF and fluorescein angiography, especially when they show the expected parafoveal pattern rather than a competing disease process.

In practice, the diagnosis is strongest when clinicians review OCT, FA, FAF, longitudinal imaging, and the patient’s medical and medication history together. Corners are most often cut when the diagnosis is made from a quick look at isolated cystic OCT spaces or temporal vascular changes without checking for diabetes, hypertension, prior vein occlusion, traction, or medication toxicity.

Modern Retina: With revakinagene taroretcel (Encelto) now approved as a surgically implanted therapy, how does the arrival of a real treatment change the stakes of diagnostic accuracy, and what does responsible patient selection look like in this setting?

Banoub: The approval of revakinagene taroretcel-lwey (Encelto) changes the stakes because MacTel is no longer just a diagnosis that informs observation; it is now a diagnosis that can lead to an invasive surgically implanted therapy with real risks. That means diagnostic accuracy matters more than ever, because treating the wrong disease exposes patients to procedural complications without benefit.

Responsible patient selection should therefore mean confirming MacTel with full multimodal imaging and longitudinal review before treatment, rather than relying on a partial exam or a billing code. Our study’s message is that patients should have careful evaluation of OCT, FA, FAF, and clinical history, and referral to a retina specialist is especially appropriate when the diagnosis is uncertain, atypical, or being considered for treatment.

Modern Retina: If a comprehensive ophthalmologist or referring physician took one thing away from this work, what should it be? And when should a patient carrying a possible MacTel2 diagnosis be referred to a retina specialist for confirmation?

Banoub: The single biggest takeaway is that MacTel2 should not be diagnosed from one feature alone, especially not from temporal telangiectasia, microaneurysms, or cystic OCT changes in isolation. Our findings support a structured, multimodal, and longitudinal approach, because many mimics can look similar at a glance, and mislabeling has become more consequential now that treatment exists.

A patient carrying a possible MacTel diagnosis should be referred to a retina specialist when the findings are atypical, incomplete, or confounded by diabetes, hypertension, vein occlusion, traction, AMD, or medication toxicity. Referral is also warranted whenever treatment is being considered, because the confirmation needs to be strong enough to justify a surgical implant and its associated risks.