Dupixent Eye Problems and Ocular Side Effects

The 30% Conjunctivitis Signal Sanofi Downplayed

During Phase 3 clinical trials for Dupixent in moderate-to-severe atopic dermatitis, conjunctivitis emerged as a standout safety signal. In the SOLO 1 and SOLO 2 trials, conjunctivitis occurred in approximately 10 percent of Dupixent-treated patients versus 2 percent on placebo. In the CHRONOS trial (Dupixent plus topical corticosteroids), the rate climbed to nearly 20 percent. Post-hoc analyses and real-world registry data later pushed estimates above 30 percent for the broadest definition of ocular adverse events.

Sanofi and Regeneron included conjunctivitis as a listed adverse reaction on the Dupixent label, but the labeling framed the issue as a manageable, typically mild side effect. The prescribing information did not adequately convey the risk of progression to keratitis, corneal ulceration, or vision loss. Dermatologists — who prescribe the majority of Dupixent for atopic dermatitis — are not trained to evaluate or manage serious ocular complications. Plaintiffs allege that Sanofi should have included a stronger warning directing prescribers to refer patients for ophthalmological evaluation at the first sign of eye symptoms.

The dose-response relationship in the clinical data is particularly damaging to the defense. Higher Dupixent doses consistently produced higher rates of ocular events, establishing a classic pharmacological dose-response signal that supports causation. Sanofi's own pharmacovigilance team flagged the ocular signal internally before FDA approval, yet the company proceeded with a label that plaintiffs characterize as inadequately urgent.

Beyond Pink Eye: Keratitis, Corneal Ulcers, and Vision Threats

While conjunctivitis — redness, tearing, and discomfort — is the most frequently reported ocular event, the more serious complications are the ones driving litigation. Keratitis (corneal inflammation) develops when the chronic ocular surface inflammation breaches the corneal epithelium, causing pain, photophobia, and blurred vision. Keratitis can progress to corneal ulceration, where the corneal tissue breaks down, creating an open wound susceptible to bacterial infection. Microbial keratitis superimposed on Dupixent-induced corneal compromise can lead to corneal perforation — a surgical emergency requiring corneal transplantation.

Published case reports describe Dupixent patients developing bilateral keratitis severe enough to require topical cyclosporine, oral doxycycline, and autologous serum tears — aggressive interventions that go far beyond the 'eye drops' management suggested by the Dupixent label. At least four published case reports document corneal perforation in dupilumab-treated patients, with two requiring emergency penetrating keratoplasty (full-thickness corneal transplant). These patients face lifelong risks of graft rejection, chronic immunosuppression, and permanent visual impairment.

Limbal Stem Cell Deficiency: A Permanent Consequence

Limbal stem cells reside at the border (limbus) between the cornea and the sclera and are responsible for continuous regeneration of the corneal epithelium. Chronic inflammation of the ocular surface can destroy these stem cells, leading to limbal stem cell deficiency (LSCD). Once LSCD develops, the corneal surface cannot maintain its transparent epithelium, and conjunctival tissue grows over the cornea (conjunctivalization), causing progressive opacification and vision loss. LSCD is irreversible without limbal stem cell transplantation — a complex and often unsuccessful procedure.

For Dupixent patients, the pathway to LSCD begins with chronic conjunctivitis that is either untreated or inadequately treated because the prescribing dermatologist lacks the ophthalmological expertise to recognize the progression. By the time the patient is referred to an ophthalmologist, the limbal stem cells may already be compromised. This delay-in-referral pathway is a key liability theory: Sanofi's failure to include explicit referral guidance on the label contributed to the inadequate ophthalmological follow-up that allowed LSCD to develop.

Why Dermatologists Were the Wrong Gatekeepers for Eye Safety

Dupixent for atopic dermatitis is primarily prescribed by dermatologists, who have limited training in diagnosing and managing complex ocular surface disease. When a Dupixent patient reports red, watery eyes, a dermatologist may recommend over-the-counter artificial tears or topical antihistamine drops — appropriate for allergic conjunctivitis but insufficient for the immunologically driven ocular inflammation caused by IL-13 blockade. The prescribing information did not include a specific recommendation for baseline ophthalmological examination or referral criteria for worsening eye symptoms.

This prescriber-mismatch dynamic — a drug with significant ocular toxicity prescribed by physicians with minimal eye training — is central to the failure-to-warn theory in eye-injury cases. Plaintiffs argue that Sanofi should have included explicit warnings directing dermatologists to refer patients for ophthalmological evaluation at the first sign of persistent conjunctivitis, and that the label should have contraindicated continuation of Dupixent in patients developing keratitis.

Proving Ocular Injury Claims Against Sanofi

Dupixent ocular injury claims require ophthalmological documentation of the specific eye condition, temporal correlation to Dupixent use, and evidence that the severity exceeded what was warned on the label. Patients with keratitis, corneal ulceration, corneal perforation, or LSCD have the strongest claims because these conditions are severe, often permanent, and were not adequately warned against. Pre-Dupixent eye examination records establishing baseline ocular health strengthen the case by demonstrating that the eye condition developed de novo during treatment.

Damages in ocular injury cases include past and future medical expenses (ophthalmological care, surgical procedures, lifelong monitoring), pain and suffering from chronic eye pain and photophobia, loss of visual acuity affecting employment and quality of life, and emotional distress from living with impaired or lost vision. While individual ocular injury damages may be lower than fatal CTCL cases, the volume of affected patients — potentially tens of thousands given the 30 percent incidence rate — makes ocular injury a significant component of the overall Dupixent litigation.

Current Treatment Protocols for Dupixent Eye Complications

Management of dupilumab-associated ocular surface disease has evolved as ophthalmologists have gained experience with the condition. First-line treatment includes preservative-free artificial tears, warm compresses, and lid hygiene. For moderate cases, topical anti-inflammatory drops (fluorometholone 0.1% or loteprednol etabonate 0.5%) and topical cyclosporine 0.05% are used. Severe cases may require tacrolimus ointment, autologous serum tears, or therapeutic contact lenses. Patients developing keratitis or corneal compromise should be counseled about Dupixent discontinuation, though some patients face the difficult choice between eczema control and eye health — a choice Sanofi's incomplete labeling failed to prepare them for.

Dupixent-associated ocular adverse events span a severity spectrum from mild conjunctivitis (eye redness and tearing) to severe keratitis (corneal inflammation) and corneal perforation. The mechanism involves IL-13 blockade disrupting the ocular surface epithelium and goblet cell function, reducing mucin production in the tear film, and creating a pro-inflammatory environment on the corneal and conjunctival surfaces. The conjunctiva — the clear membrane covering the white of the eye and inner eyelids — becomes chronically inflamed, leading to conjunctival cicatrization (scarring) in severe cases. This process can compromise the limbal stem cells responsible for corneal epithelial regeneration, leading to limbal stem cell deficiency and progressive corneal opacification.

Clinical trials for Dupixent in atopic dermatitis reported conjunctivitis rates of 8 to 30 percent depending on the trial and dosing regimen, compared to 2 to 3 percent for placebo. Post-marketing surveillance has revealed that the incidence and severity are higher in real-world use than the clinical trial data suggested. A 2023 systematic review in Ophthalmology found that dupilumab-associated ocular surface disease affects up to 38 percent of treated patients, with 5 to 10 percent experiencing moderate-to-severe manifestations requiring ophthalmological intervention.

The causation link between Dupixent and ocular adverse events is one of the most well-established in the litigation. IL-13 plays a critical role in goblet cell differentiation and mucin production on the ocular surface. By blocking IL-13, Dupixent disrupts the normal tear film architecture, leading to aqueous-deficient and evaporative dry eye, conjunctival inflammation, and secondary infectious or sterile keratitis. Animal models have demonstrated that IL-13 knockout mice develop spontaneous ocular surface inflammation, supporting the biological plausibility of dupilumab-induced eye disease. Sanofi's own clinical trial data showed a statistically significant dose-dependent increase in conjunctivitis — higher doses produced more eye problems — further strengthening the causal inference.