TJ-CEO
2011 , Vol 6 , Num 3
Changes in Corneal Biomechanics Following Intraocular Pressure Reduction by Trabeculectomy
1S.B. Ulucanlar Göz Eğitim ve Araştırma Hastanesi 2. Göz Kliniği, Ankara, Uz. Dr.2S.B. Ulucanlar Göz Eğitim ve Araştırma Hastanesi 2. Göz Kliniği, Ankara, Asist. Dr.
3S.B. Ulucanlar Göz Eğitim ve Araştırma Hastanesi 2. Göz Kliniği, Ankara, Doç. Dr.
4S.B. Ulucanlar Göz Eğitim ve Araştırma Hastanesi 2. Göz Kliniği, Ankara, Prof. Dr. Purpose: To evaluate and compare corneal biomechanical parameters in primary open angle glaucoma patients prior to and following intraocular pressure (IOP) reduction by trabeculectomy.
Materials and Methods: We reviewed the charts of 23 patients with one eye that had undergone succesful trabeculectomy. Corneal hysteresis (CH), corneal resistance factor (CRF) that were recorded prior to and 1 week, 1 month and 3 months after trabeculectomy in paired eyes of the same patients were compared. The correlations between postoperative change in corneal biomechanical parameters and IOP reduction were also analysed.
Results: The mean preoperative cornea compensated intraocular pressure (IOPcc) was 26.6±4.0 mmHg and the mean postoperative IOPcc after 1 week was 15.2±7.2 mmHg (p<0.001). Preoperative CH increased significantly from 6.4±1.2 mmHg to 8.6±1.5 mmHg at postoperative 1st week (p<0.001), with no significant changes after that. CRF on the other hand decreased from 9.7±2.5 to 8.0±1.8 at 1st week (p=0.003). Changes in CH was negatively correlated with changes in IOPcc (r=-0.642, p=0.001); and changes in CRF was positively correlated with changes in IOPcc (r=0.689, p<0.001). Central corneal thickness was not changed significantly during follow up period.
Conclusion: In our investigation, corneal biomechanic was influenced by IOP. CH which was significantly lower in glaucomatous eyes with high pressure, and partial recovery occurred after successful IOP lowering therapy. Further studies are needed to answer the question of whether or not changes in corneal biomechanics after IOP reduction has a role in alterating the progression of glaucomatous damage. Keywords : Trabeculectomy, intraocular pressure, corneal hysteresis, corneal resistance factor