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Antonio Longo, Teresio Avitabile, Vincenza Bonfiglio, Marco Franco, Iacopo Macchi, Davide Scollo, Andrea Russo, Alessandra Pizzo, Matteo Fallico, Michele Reibaldi; THE EFFECT OF VALSALVA MANEUVER ON CHOROIDAL THICKNESS IN PATIENTS WITH KERATOCONUS. Invest. Ophthalmol. Vis. Sci. 2018;59(9):3948.
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To evaluate the effect of Valsalva maneuver on subfoveal Choroidal Thickness (ChT) in patients with keratoconus
In a prospective case control study, the subfoveal ChT was assessed by Spectralis SD-OCT (Heidelberg engineering, Germany) with Enhanced Depth Imaging (EDI) in a group of patients with keratoconus enrolled for cross-linking. Patients with corneal alterations or media opacities that did not allowed high quality OCT scan, or with any retinal, neurological or cardiovascular disease were excluded.A group of age-sex matched healthy subjects served as control.ChT was determined in horizontal linear OCT scan centered on the fovea, as the vertical distance from the hyperreflective line of the retinal pigment epithelium to the line of the inner surface of the sclera. Measurements were performed at baseline, and after Valsalva maneuver, with the follow-up function.Valsalva maneuver was performed by blowing forcefully against one hand while occluding the nose with fingers, for at least 15 seconds and during the scanning period.First, baseline measurement was taken in both eyes, followed by a Valsalva measurement in one eye. After 10 minutes of rest, a new baseline measurement was taken in fellow eye, followed by a Valsalva measurement.Arterial blood pressure, at baseline and after Valsalva Maneuver, was assessed by an automatic sphygmomanometer.
Twenty-four patients with keratoconus (15 m, 9 f, age 19-27 yrs, mean 23±4) (KC group) and 24 age-sex matched healthy controls were included in the study. In KC group, mean K1 was 51.4±2.9 D, mean K2 was 45.8±1.8 D, mean CCT was 473±42 µ.During Valsalva maneuver, mean arterial blood pressure increased significantly in KC group (from 80±7 mmHg to 97±10 mmHg) and in controls (from 85±10 mmHg to 103±8 mmHg) (both p<0.001, paired t-test).In KC patients mean ChT was 316±71 µ at baseline, and 349±78 µ after Valsalva maneuver (+10.5%, p=0.001, paired t-test); in healthy controls mean ChT was 330±56 µ at baseline, and 332±58 after Valsalva maneuver (+0.6%, p= 0.580, paired t-test).No difference was seen between two groups at baseline or after Valsalva maneuver (respectively p=0.463 and p=0.406, unpaired t-test)
Choroidal thickness increases in patients with keratoconus after Valsalva Maneuver.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
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