# Case report: Type V ophthalmia nodosa induced by pine processionary caterpillar setae with long-term complications

## TL;DR

A rare eye disease caused by contact with pine processionary caterpillar hairs led to severe inflammation and long-term vision complications in a 55-year-old man.

## Contribution

This case report highlights the rare Type V ophthalmia nodosa and its long-term complications following caterpillar setae exposure.

## Key findings

- Prompt surgical removal of setae and anti-inflammatory treatment controlled acute inflammation.
- Persistent complications included cystoid macular edema, epiretinal membrane, and cataract over 48 months.
- Long-term visual acuity stabilized at 0.1 in the affected eye despite treatment.

## Abstract

Nodular ophthalmia, a rare and specific inflammatory ocular disease, is typically triggered by contact with setae from Lepidoptera larvae. Type V according to the Cadera classification represents the rarest and prognostically poorest variant.

A 55-year-old male developed immediate ocular pain, foreign body sensation, and blurred vision in his left eye following contact with a Thaumetopoea pityocampa (pine processionary caterpillar). Despite prompt removal of visible setae and initiation of topical non-steroidal anti-inflammatory drug (NSAID) therapy at a local facility, uncontrolled intraocular inflammation necessitated referral to our institution. Initial ophthalmic examination revealed best-corrected visual acuity (BCVA) of hand motion (HM) at 15 cm in the left eye, conjunctival injection, and significant inflammatory reactions in the anterior chamber, iris, and vitreous. Two setae were identified: one embedded subconjunctivally and another within the anterior chamber near the anterior iris surface. Combined topical and systemic anti-inflammatory/anti-infective therapy, surgical setae extraction, and diagnostic pars plana vitrectomy (PPV) were performed, achieving control of the intraocular inflammation. At 16 months postoperatively, persistent mild anterior chamber inflammation, cystoid macular edema (CME), epiretinal membrane (ERM), and complicated cataract were observed. At the final 48-month follow-up, BCVA in the left eye stabilized at 0.1.

Precise localization of setae-induced nodular ophthalmia requires comprehensive physical examination and appropriate imaging. Severe posterior segment inflammation mandates prompt surgical setae removal to preserve visual potential. Long-term, meticulous postoperative surveillance is crucial to monitor inflammatory sequelae and intervene promptly for complications.

Not applicable.