Abstract
Purpose: :
Central corneal thickness (CCT) is related to glaucoma risk. It has been suggested that this relationship may represent a biological link between CCT and the material properties of the eye wall, in particular the lamina cribrosa. We sought to determine whether change in axial length following trabeculectomy is related to clinical measures of corneal factors that might serve as surrogates for the material properties of the eye.
Methods: :
Twelve patients undergoing primary trabeculectomy had axial length (AL) measured by laser interferometry (IOLMasterTM), corneal hysteresis (CH) by the Reichert Ocular Response Analyzer, CCT by ultrasonic pachymetry and intraocular pressure measured by Goldmann Applanation (IOPGAT), Dynamic Contour Tonometry (IOPDCT) and Ocular Response Analyzer (IOPORA) prior to surgery and at the 1st month after surgery. A comparison of baseline values of Hysteresis and AL change (ΔAL) was made.
Results: :
Baseline mean IOPGAT was 17.0 ± 5.4 mmHg; at the 1–month postoperative visit, the mean IOPGAT was 10.7 ± 4.7 mmHg (P=0.003). Similar IOP readings were obtained with IOPDCT and IOPORA. Baseline AL was 24.23 ± 1.66 mm; at the 1–month postoperative visit, the mean ΔAL was 23.87 ± 1.63 mm (P=0.002). ΔAL change was correlated to baseline CH (r=0.64, P=0.03) but neither to ΔCCT (r=0.14, P=0.67) nor to ΔIOP (r=0.50, P=0.10).
Conclusions: :
The shortening of an eye following surgical decompression is related to the compliance of the eye wall. In our study, ΔAL after surgical decompression was related to corneal hysteresis, independent of CCT or ΔIOP. This data supports the hypothesis that corneal hysteresis is related to the material properties of the entire eye wall.
Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials