Purpose: To detect and quantify changes in optic nerve morphology after glaucoma surgery, using Heidelberg Retina Tomograph (HRT), and in visual field global indices, using Humphrey perimeter. Methods: The authors enrolled 14 adult patients with chronic open-angle glaucoma (PAOG) undergoing incisional glaucoma surgery, such as trabeculectomy and deep sclerectomy, for progressive glaucoma damage. Intraocular pressure (IOP), visual field and HRT were performed 2 weeks before surgery and then repeated 3 and 6 months after. Results: Our clinical trial evidenced a IOP reduction superior to 40% after glaucoma surgery. The pre-operative average IOP was 24.36 ± 5 mmHg: 3 months after surgery average IOP was 12.07 ± 3.12 mmHg, while it was reduced to 10.64 ± 2.84 mmHg after 6 months. Changing in optic nerve morphology parameters, using Heidelberg Retinal Tomograph, revealed a significant increase in the overall mean RNFL thickness, in Rim Area and Rim Volume, whereas Cup Area, Cup Volume, Cup/Disc Area Ratio, and Maximum Cup Depth decreased. Visual field functional global indices, such as MD and PSD, improved a little bit less than morphological indices. In 57% of our patients we discovered an improvement of all the considered parameters. Multiple linear regression analysis demonstrated that, among the optic disk sectors, the temporal and the super nasal octant improved in direct proportion to the magnitude of IOP reduction. The improvement appeared to be significant in the first 3 months of follow-up, probably because of the immediate IOP reduction after surgery. By HRT, we noticed an increase in retinal fibres of 0.9 microns and of 0.4 microns every mmHg of IOP reduction, respectively in the first 3 months and in the second period of follow-up. Moreover, between risk factors, such as age, pre-surgery MD, IOP variation, the last one was the most important in changing of optic disc parameter. Regarding visual field global indices, we registered an average evolution from the 4th to the 3rd - 4th stage, using the Brusini Glaucoma Staging System. Conclusions: Our study demonstrated the beneficial effect of IOP reduction, obtained with glaucoma surgery techniques, as trabeculectomy and deep-sclerectomy, on visual field global indices and optic disc parameter evaluated by Heidelberg Retinal Tomograph.
Visual field global indices and heidelberg retinal tomograph II parameters after glaucoma surgery
NARDI, MARCO;
2008-01-01
Abstract
Purpose: To detect and quantify changes in optic nerve morphology after glaucoma surgery, using Heidelberg Retina Tomograph (HRT), and in visual field global indices, using Humphrey perimeter. Methods: The authors enrolled 14 adult patients with chronic open-angle glaucoma (PAOG) undergoing incisional glaucoma surgery, such as trabeculectomy and deep sclerectomy, for progressive glaucoma damage. Intraocular pressure (IOP), visual field and HRT were performed 2 weeks before surgery and then repeated 3 and 6 months after. Results: Our clinical trial evidenced a IOP reduction superior to 40% after glaucoma surgery. The pre-operative average IOP was 24.36 ± 5 mmHg: 3 months after surgery average IOP was 12.07 ± 3.12 mmHg, while it was reduced to 10.64 ± 2.84 mmHg after 6 months. Changing in optic nerve morphology parameters, using Heidelberg Retinal Tomograph, revealed a significant increase in the overall mean RNFL thickness, in Rim Area and Rim Volume, whereas Cup Area, Cup Volume, Cup/Disc Area Ratio, and Maximum Cup Depth decreased. Visual field functional global indices, such as MD and PSD, improved a little bit less than morphological indices. In 57% of our patients we discovered an improvement of all the considered parameters. Multiple linear regression analysis demonstrated that, among the optic disk sectors, the temporal and the super nasal octant improved in direct proportion to the magnitude of IOP reduction. The improvement appeared to be significant in the first 3 months of follow-up, probably because of the immediate IOP reduction after surgery. By HRT, we noticed an increase in retinal fibres of 0.9 microns and of 0.4 microns every mmHg of IOP reduction, respectively in the first 3 months and in the second period of follow-up. Moreover, between risk factors, such as age, pre-surgery MD, IOP variation, the last one was the most important in changing of optic disc parameter. Regarding visual field global indices, we registered an average evolution from the 4th to the 3rd - 4th stage, using the Brusini Glaucoma Staging System. Conclusions: Our study demonstrated the beneficial effect of IOP reduction, obtained with glaucoma surgery techniques, as trabeculectomy and deep-sclerectomy, on visual field global indices and optic disc parameter evaluated by Heidelberg Retinal Tomograph.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
