Tx 20 full auto tonometer

Each participant underwent visual acuity measurement, autorefractometry (HRK-7000A Auto Refractor; Huvitz, Inc., Anyang-si, South Korea), non-contact tonometry (TX-20 Full Auto Tonometer; Canon, Inc., Tokyo, Japan), slit-lamp examination, and fundus photography (TRC-NW8 non-mydriatic retinal camera, Topcon, Tokyo, Japan; D7500 DSLR camera, Nikon, Tokyo, Japan). Diagnosis and grading of HTNR were performed by two ophthalmologists specialized in retinal diseases using indirect fundoscopy and fundus photography; grading was based on Keith–Wagener–Barker and Mitchell–Wong classifications⁶ (link) (κ = 0.883). Differing diagnoses were reassessed and diagnosed by a senior chief ophthalmologist. The arteriovenous ratio was manually calculated using Image J 1.51 (National Institutes of Health, Bethesda, MD, USA). The diameters of arterioles and venules 1.5 papillary diameters to the optic disc were measured 10 times to obtain an average. The arteriovenous ratio cutoff point for determining retinal arteriole narrowing was set at ½. The distribution of retinopathy grades in each group was listed in Table 1.

This study was approved by the Institutional Review Board of the Zhongshan Ophthalmic Center, Sun Yat-sen University, China, and adhered to the tenets of the Declaration of Helsinki. Informed consent was obtained from each of the enrolled subjects. Subjects without ocular abnormity and intraocular pressure (IOP) lower than 21 mmHg were included. Patients with systemic diseases, including diabetes, hyperlipidemia, and hypertension, refractive media opacity and high refractive error (more than − 6 diopters) were excluded. Twenty eyes of 20 individuals with no ophthalmic pathology were enrolled from April 4th to May 3rd in 2018. All participants underwent blood pressure and heart beat measurements as well as intraocular pressure (IOP) evaluation using an automated non-contact tonometer (TX-20, Full Auto Tonometer, Canon, U.S.A.).

Routine ophthalmic examinations including best-corrected visual acuity (BCVA), slit lamp examination, intraocular pressure (IOP), anterior chamber depth (ACD), fundus examination, and B-scan ultrasonography were performed for all patients. IOP was measured using non-contact tonometry (TX-20 Full Auto Tonometer, Canon Inc., Tokyo, Japan) three times, and the mean values were used in subsequent statistical analyses. Choroidal detachment and hypotony maculopathy were measured by B-scan ultrasonography and optical coherence tomography (OCT5000, Carl Zeiss Meditec, Inc., Dublin, CA, USA), respectively. To identify and confirm the extent and location of the cyclodialysis clefts, UBM was performed preoperatively and postoperatively.