Unilateral Keratoconus In A Patient With Turner Syndrome Presenting For Refractive Surgery Evaluation

To report a case of unilateral Keratoconus detected during refractive surgery evaluation in a patient with Turner syndrome, and to emphasize the importance of detailed corneal topographic imaging in patients with systemic disorders that may affect ocular structures.

This case was managed at a tertiary referral ophthalmology center in Istanbul, Turkey, serving as a regional hub for complex ocular cases. The clinic specializes in retinal, corneal and uveitis disorders and routinely manages patients with chronic visual impairment, post-refractive surgery complications, and other challenging ophthalmic conditions.

A 40-year-old woman presented to our ophthalmology clinic with a long-standing complaint of decreased vision in her left eye. She sought consultation regarding the possibility of laser refractive surgery. Her medical history was notable for Turner syndrome, diagnosed approximately 25 years earlier with amenorrhea, Ulcerative colitis and Hypertension. Her current medications included sulfasalazine, hormone replacement therapy, and antihypertensive agents. She had no history of ocular or systemic surgery.

Autorefraction measurements were −1.00 −0.75 25° / −4.00 −3.50 175°. Visual acuity without correction was 20/20 in the right eye, whereas the left eye had an uncorrected visual acuity of 20/130 and a best-corrected visual acuity of 20/30. Slit-lamp examination revealed a normal anterior segment in both eyes with normal intraocular pressure. Fundus examination demonstrated tilted optic discs in both eyes, normal maculae, and increased retinal vascular tortuosity. Corneal topography revealed inferior corneal steepening in the left eye with keratometric values of K1 48.5 D and K2 52.3 D, Kmax of 59.4 D, and a thinnest corneal thickness of 493 µm, findings consistent with keratoconus. In contrast, the right eye showed relatively normal corneal parameters, with K1 45.3 D, K2 46.2 D, and a thinnest corneal thickness of 539 µm, without clear ectatic changes. Based on these findings, the patient was diagnosed with unilateral keratoconus predominantly affecting the left eye.

Turner syndrome has been associated with a variety of ocular abnormalities involving the eyelids, ocular alignment, and refractive status. Previous studies have reported a high prevalence of refractive errors in these patients. Structural abnormalities such as tilted optic discs and increased retinal vascular tortuosity have also been described. Although the association between Turner syndrome and keratoconus is not well established, clinicians should be aware of the possibility of corneal ectasia in these patients. Comprehensive corneal imaging should be performed in Turner syndrome patients undergoing evaluation for refractive surgery.