Typical inferior, feather-shaped lens opacity may suggest keratoconus, especially in cases that do not otherwise clinically indicate the disorder, according to research published in the Journal of Ophthalmic & Vision Research.
Researchers assessed the medical charts of 33,368 refractive surgery candidates without lens opacity, 21 of which had typical feather-shape lens opacity (inferior sectoral and triangular). They performed ophthalmic exams on the 21 patients consisting of refraction, biomicroscopy, and fundus evaluation, and obtained information on demographics, medical history, and drug intake through an interview.
Investigators noted that 2122 (6.4%) participants in the initial analysis had keratoconus, but no lens opacity. Among the 21 patients with typical feather-shape lens opacity, 20 (95.2%) had definite keratoconus (P =.001). Kerataconus was bilateral in all 20 participants, while opacity was bilateral in 5 patients. Opacity width tended to be 1 clock hour or less, and varied in density between the participants.
Patients with both keratoconus and lens-opacity (14 men 4 women, median age 27.5 years) had a median visual acuity of 20/50 (range: 20/20–20/200) and median spherical equivalent refraction of -4.00 D (range: -0.50 to -13.25). Their median mean keratometry , maximum keratometry, astigmatic keratometry, and thinnest point values were 48.8 D, 54.6 D, 3.3 D, and 475 μm, respectively. Among this cohort, 9 patients underwent lamellar keratoplasty (8 men, 1 woman). Women tended to have lower median topographic keratoconus classification (TKC) compared with men (1.5 vs 2.0).
Investigators stress the clinical relevance of their findings for patients not presenting with the typical clinical manifestations of keratoconus: “Our study revealed that the typical inferior feather-shape lens opacity is suggestive of an associated keratoconus, particularly in cases who might not show the clinical signs.”
Limitations of the study include its retrospective nature and reliance on participant reporting to identify genetic evidence.
Salouti R, Khosravi A, Fardaei M, et al. Inferior spear-like lens opacity as a sign of keratoconus. J Ophthalmic Vis Res. 2022;17(1):12-18. doi: 10.18502/jovr.v17i1.10165