The ophthalmic complaints of a 56-year-old male patient started on 21st of March 2021. He was discharged from the COVID department 2 days earlier, where he had been treated for moderately severe bilateral COVID pneumonia for a week. The patient was treated with remdesivir, favipiravir, and dexamethasone. He was discharged with a negative SARS-CoV2 antigen test result. His medical history included well-balanced hypertonia and bronchial asthma. Laser-assisted in situ keratomileusis was performed in both eyes five years earlier.
The patient visited an ophthalmology office with redness of the right eye for one day. Severe conjunctival and ciliary hyperemia with chemosis was noted. Acute conjunctivitis was diagnosed, and topical nonsteroidal anti-inflammatory drugs and ofloxacin were prescribed. As the patient did not improve after one week, the therapy was changed to tobramycin-dexamethasone combined eye drops. Some improvement was observed in the next two weeks when the treatment was interrupted, and only artificial tear drops were administered. Conjunctival culture was negative. During the following week, the redness of the inferior bulbar conjunctiva increased and a paralimbal nodule developed (Fig. 1). At this point, the patient was referred to our tertiary referral center. At presentation, he had full visual acuity without correction on either side, and the intraocular pressure was normal. In the right eye at the 6-o’clock position near the limbus, a whitish pea-sized nodule was seen with conjunctival, episcleral, and scleral hyperemia over it and in the surroundings. The cornea was intact and the anterior and posterior segments showed no abnormalities. The left eye was quiet and intact.
The patient was diagnosed with nodular anterior scleritis. The differential diagnosis raised the possibility of post-COVID manifestation, a different exogenous or endogenous infectious origin, and non-infectious etiology, namely immune-mediated inflammation or granulomatous inflammatory reaction for foreign body.
Ultrasound biomicroscopy (UBM) of the nodule revealed a trans-scleral round mass with inhomogeneous inner reflectivity (Fig. 2). Inside the mass, discontinuity of the scleral echo was detected with a target-shaped structure replacing the sclera, with a 0.5 mm structure with moderate to high reflectivity in the middle. This picture raised the possibility of either a foreign body or helminth, with surrounding granulomatous inflammation.
Surgical exploration was performed because of the suspicion of helminthiasis or a foreign body. A fragile white material was found over and under the hole in the sclera, but no foreign body or helminth was observed. Samples were collected for histology and laboratory tests, and debridement and rinsing with cefuroxime solution were performed. A scleral patch was sutured to restore the integrity of the sclera, and the conjunctiva was closed using interrupted sutures.
Histological examination revealed the presence of granulation tissue. COVID-19 PCR from the intraoperatively taken sample was negative; however, methicillin-resistant Staphylococcus aureus (MRSA) strain grew from the culture, which showed in vitro sensitivity for sulfamethoxazole/trimethoprim, Doxycycline, Amikacin, Tobramycin, Gentamicin, Linezolid, Rifampicin, Vancomycin, and Teicoplanin, and resistance to Oxacillin, Amoxicillin/clavulanic acid, Cefazolin, Cefuroxime, Erythromycin, Clarithromycin, Azithromycin, Clindamycin, Ciprofloxacin, and Levofloxacin.
Systemic work-up yielded negative results for chest radiography, serum angiotensin convertase enzyme, lues serology, and immune serology. However, the result of the quantiferon-gold test was positive. Pulmonology consultation was required, and although the histology showed granulation tissue, not granuloma, and so it was unlikely that Mycobacterium pneumoniae had a role in the ocular inflammation – 3 month-long isonicotinic acid hydrazide (INH) treatment was suggested.
For local treatment, subconjunctival vancomycin, then topical vancomycin, and combined tobramycin-dexamethasone eye drops were prescribed. Inflammation resolved slowly over the next five months (Fig. 3).