Aistė Kadziauskienė1, Ernesta Jašinskienė2, Rimvydas Ašoklis3, Eugenijus Lesinskas3, Tomas Rekašius4, Jacqueline Chua5, Ching-Yu Cheng6, Jean Martial Mari7, Michaël J A Girard8, Leopold Schmetterer9. 1. Clinic of Ears, Nose, Throat and Eye Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania; Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania. Electronic address: aistedam@gmail.com. 2. Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania. 3. Clinic of Ears, Nose, Throat and Eye Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania; Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania. 4. Department of Mathematical Statistics, Vilnius Gediminas Technical University, Vilnius, Lithuania. 5. Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore. 6. Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. 7. GePaSud Laboratory, University of French Polynesia, Tahiti, French Polynesia. 8. Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmic Engineering & Innovation Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore. 9. Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
Abstract
PURPOSE: To evaluate changes in lamina cribrosa (LC) shape, curvature, and depth after trabeculectomy. DESIGN: Prospective, observational case series. PARTICIPANTS: A total of 112 patients (118 eyes) with open- or closed-angle glaucoma undergoing trabeculectomy. METHODS: The optic nerve head was imaged using enhanced depth imaging spectral-domain OCT before trabeculectomy and at 6 follow-up visits throughout the first postoperative year. The anterior LC surface and Bruch's membrane opening were marked in the serial horizontal B scans for the analysis of LC parameters using Morphology 1.0 software. Postoperative morphologic LC changes were assessed. MAIN OUTCOME MEASURES: The postoperative LC global shape index (GSI), nasal-temporal (N-T) and superior-inferior (S-I) curvatures, and mean and sectoral LC depth (LCD). RESULTS: The mean LC GSI increased only during the early postoperative period (P = 0.02), resulting in a change toward the saddle-rut shape. There was a flattening of the LC curvature in N-T (P < 0.001) and S-I (P = 0.003) meridians 12 months after trabeculectomy. A shallowing of the mean and sectoral LCD from baseline was significant throughout the entire follow-up period (P < 0.001) and progressed up to postoperative month 6. Twenty-eight patients showed a deepening of the LC from baseline in at least 1 visit. Eyes with shallower LCD compared with baseline responded to intraocular pressure (IOP) reduction with greater movement anteriorly than eyes with deeper LCD (P = 0.002). Greater IOP reduction (P = 0.007), less retinal nerve fiber layer thinning over the year (P = 0.003), and more superiorly-inferiorly curved baseline LC (P = 0.001) were associated with an increase in GSI. Younger age and IOP reduction were related to LC shallowing (P < 0.001, P = 0.002) and N-T flattening (P < 0.001). CONCLUSIONS: In most eyes, trabeculectomy resulted in long-term flattening and shallowing of the LC. However, in some eyes, LC deepened from baseline. Change in LC global shape appeared to be temporal. Reduction in IOP plays an important role in the early phase of LC change; however, in the later phase, LC remodeling may play a crucial role in view of stable IOP.
PURPOSE: To evaluate changes in lamina cribrosa (LC) shape, curvature, and depth after trabeculectomy. DESIGN: Prospective, observational case series. PARTICIPANTS: A total of 112 patients (118 eyes) with open- or closed-angle glaucoma undergoing trabeculectomy. METHODS: The optic nerve head was imaged using enhanced depth imaging spectral-domain OCT before trabeculectomy and at 6 follow-up visits throughout the first postoperative year. The anterior LC surface and Bruch's membrane opening were marked in the serial horizontal B scans for the analysis of LC parameters using Morphology 1.0 software. Postoperative morphologic LC changes were assessed. MAIN OUTCOME MEASURES: The postoperative LC global shape index (GSI), nasal-temporal (N-T) and superior-inferior (S-I) curvatures, and mean and sectoral LC depth (LCD). RESULTS: The mean LC GSI increased only during the early postoperative period (P = 0.02), resulting in a change toward the saddle-rut shape. There was a flattening of the LC curvature in N-T (P < 0.001) and S-I (P = 0.003) meridians 12 months after trabeculectomy. A shallowing of the mean and sectoral LCD from baseline was significant throughout the entire follow-up period (P < 0.001) and progressed up to postoperative month 6. Twenty-eight patients showed a deepening of the LC from baseline in at least 1 visit. Eyes with shallower LCD compared with baseline responded to intraocular pressure (IOP) reduction with greater movement anteriorly than eyes with deeper LCD (P = 0.002). Greater IOP reduction (P = 0.007), less retinal nerve fiber layer thinning over the year (P = 0.003), and more superiorly-inferiorly curved baseline LC (P = 0.001) were associated with an increase in GSI. Younger age and IOP reduction were related to LC shallowing (P < 0.001, P = 0.002) and N-T flattening (P < 0.001). CONCLUSIONS: In most eyes, trabeculectomy resulted in long-term flattening and shallowing of the LC. However, in some eyes, LC deepened from baseline. Change in LC global shape appeared to be temporal. Reduction in IOP plays an important role in the early phase of LC change; however, in the later phase, LC remodeling may play a crucial role in view of stable IOP.