Betul S Uysal1, Fatma Yulek, Pinar Nalcacioglu, Ozge Sarac, Mucella A Yorgun, Nurullah Cagil. 1. Department of Ophthalmology (BSU, OS, MAY), Ankara Ataturk Training and Research Hospital, Ankara, Turkey; and Department of Ophthalmology (FY, PN, NC), Ankara Ataturk Training and Research Hospital, Yildirim Beyazit University, Ankara, Turkey.
Abstract
OBJECTIVE: To investigate corneal biomechanical properties among individuals with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) compared to healthy gender- and age-matched subjects. METHODS: The study subjects were separated into 2 groups: 66 eyes of 33 patients with unilateral NAION (study group) and 33 eyes of 33 healthy individuals (control group). Reichert ocular response analyzer (Reichert Ophthalmic Instruments) was used to assess corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure values. Also, central corneal thickness was measured using Scheimpflug camera combined with a Placido disc corneal topographer (Sirius; Costruzioni Strumenti Oftalmici). RESULTS: Mean CH and median CRF values were significantly lower in the affected eyes (8.8 ± 1.8 mm Hg, 9.4 mm Hg, respectively) and contralateral unaffected eyes (9.1 ± 1.6 mm Hg, 9.8 mm Hg, respectively) of NAION patients than those in the control group (9.9 ± 1.3 mm Hg, 10.4 mm Hg, respectively; all P < 0.017). Mean IOPcc was significantly higher in the affected eyes of NAION patients (19.2 ± 3.5 mm Hg) than in the eyes of control group (17.1 ± 3.6 mm Hg; P = 0.002). CONCLUSIONS: CH and CRF are significantly reduced in patients with NAION, possibly indirectly reflecting structural weakness in the lamina cribrosa.
OBJECTIVE: To investigate corneal biomechanical properties among individuals with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) compared to healthy gender- and age-matched subjects. METHODS: The study subjects were separated into 2 groups: 66 eyes of 33 patients with unilateral NAION (study group) and 33 eyes of 33 healthy individuals (control group). Reichert ocular response analyzer (Reichert Ophthalmic Instruments) was used to assess corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure values. Also, central corneal thickness was measured using Scheimpflug camera combined with a Placido disc corneal topographer (Sirius; Costruzioni Strumenti Oftalmici). RESULTS: Mean CH and median CRF values were significantly lower in the affected eyes (8.8 ± 1.8 mm Hg, 9.4 mm Hg, respectively) and contralateral unaffected eyes (9.1 ± 1.6 mm Hg, 9.8 mm Hg, respectively) of NAIONpatients than those in the control group (9.9 ± 1.3 mm Hg, 10.4 mm Hg, respectively; all P < 0.017). Mean IOPcc was significantly higher in the affected eyes of NAIONpatients (19.2 ± 3.5 mm Hg) than in the eyes of control group (17.1 ± 3.6 mm Hg; P = 0.002). CONCLUSIONS: CH and CRF are significantly reduced in patients with NAION, possibly indirectly reflecting structural weakness in the lamina cribrosa.