Topical Insulin Eye Drops As An Adjuvant Treatment In The Management Of Scleral Dellen

To show the clinical results of topical insulin eye drops as an adjuvant therapy in the treatment of scleral dellen after pterygium surgery, a rare and early postoperative complication of this intervention.

Pterygium excision may lead to scleral dellen, especially if adjuvant treatment has been used, such as mitomycin C, beta radiation, or scleral bed vascular cauterization. This condition has been reported in several publications but there is no guideline described for its treatment. In this case, we present a severe scleral defect after an uneventful pterygium surgery solved with conservative treatment including topical insulin eye drops. 

A 54-year-old man presented for evaluation due to intermittent right red eye and foreign body sensation. Ophthalmological examination revealed a 4 x 3 mm primary nasal pterygium. The rest of the anterior pole was normal and there were no systemic diseases or previous history of ocular surgery or treatment. The pterygium was operated on under topical and subconjunctival anesthesia (lidocaine 2% and epinephrine 1/200,000). An autograft of the superior conjunctiva was used to cover the scleral bed using vicryl® 7/0 (polyglactin 910) without adjuvant mitomycin C, after mild cauterization of bleeding vessels and tenon resection. 

After starting postoperative treatment, the patient presented for consultation two weeks later due to a change in color in the operated region. The examination revealed a whitish, retracted autograft, with associated mucopurulent secretions and intense surrounding hyperemia. After its removal, underlying scleral thinning was observed. Intensive topical therapy was started with artificial tears and ofloxacin 3mg/ml every two hours associated with insulin eye drops 1 IU/ml three times a day.  After progressively reducing the frequency of the antibiotic and maintaining lubrication along with insulin eye drops, there was a normalization of scleral thickness and conjunctival coverage without the need for surgical treatment.

Insulin is a peptide closely related to insulin-like growth factor 1 (IGH-1) that is capable of inducing cell migration and proliferation. The presence of insulin receptors in the lacrimal gland and on the ocular surface justifies its use in the treatment of scleral thinning.