What are the key clinical signs and symptoms that suggest a diagnosis of keratoconus in a patient?

Key clinical signs and symptoms suggesting keratoconus include progressive visual deterioration, often presenting as increasing myopia and irregular astigmatism that cannot be fully corrected with glasses. Patients typically report blurred or distorted vision and increased sensitivity to glare and light.

On clinical examination, characteristic signs include corneal thinning and protrusion, leading to a conical shape of the cornea. Slit-lamp findings may reveal Vogt’s striae (fine vertical lines in the deep stroma), Fleischer’s ring (iron deposition around the base of the cone), and corneal scarring in advanced cases.

Additional signs include Munson’s sign, where the lower eyelid shows a V-shaped indentation on downward gaze due to the conical cornea, and a characteristic scissoring reflex on retinoscopy caused by irregular astigmatism.

These clinical features, combined with patient history of progressive visual changes, strongly suggest keratoconus and warrant further corneal topography or tomography for confirmation.

These points are supported by UK clinical guidelines and are consistent with detailed descriptions in the ophthalmic literature (Lawless et al., 1989; Rabinowitz, 1998; Santodomingo-Rubido et al., 2022) ¹.