Conjunctival Autofluorescence, Cytological Changes Predict Pterygium Grade

Documenting conjunctival autofluorescence presence and patterns may help with early detection and prognosis.

Conjunctival autofluorescence patterns and cytological changes are correlated with pterygium severity or grade, according to a study published in Cornea. This is especially true in squamous metaplasia cases.

Researchers examined 86 patients with unilateral pterygium (mean age 37±13.26 years, 56% men) and 76 age and sex matched controls. They performed comprehensive exams, assessed eyes for autofluorescence, and performed impression cytology on all participants. The team repeated measurements at 6 month follow-up and compared images between patients with pterygium and controls. 

Researchers noted autofluorescence in 51% of pterygium cases compared with 0% of controls, with 65.9% of cases exhibiting autofluorescence at the leading edge. They found that 83.3% of grade 3 pterygia cases, 64.7% of grade 2 cases, and 28.9% of grade 1 cases harbored autofluorescence (P <.0005). Per impression cytology, 60% of pterygium cases demonstrated conjunctival epithelial cells, with significant squamous metaplasia present in 45% of grade 3 pterygia cases, 11.8% of grade 2 pterygia cases, and normal conjunctival epithelial cells in grade 1 pterygia (P <.0005).

The investigators assessed the clinical progression in the size of the pterygium using Tan grading and imaging. While no patients demonstrated progression in clinical grading, 9 patients exhibited progression in pterygium size (mean size  0.91±0.61 mm2). This measure was buoyed by a minor progression of visual acuity and keratometry at 6 month follow-up (P =.073 and P =.052, respectively).

“We believe the demonstration of higher frequency of both autofluorescence and squamous metaplasia, both of which are reportedly associated with sun exposure or indicate effects of solar UV radiation, in higher grades of pterygia further adds to the body of knowledge related to the etiopathogenesis of pterygium and could also serve as a useful clinical or research tip in evaluating patients,” according to the researchers.

The study was limited by its hospital-based design and short duration. 


Pai SVS, Kishore A, Sen S, Sharma N, Tandon R. Conjunctival autofluorescence and cytological changes in pterygium. Cornea. 2022;41(5):583-586. doi:10.1097/ICO.0000000000002820.