Abstract
Purpose: :
To reduce intraocular pressure (IOP) effectively in glaucoma patients surgery is often necessary. Therefore, deep sclerectomy is a safe and approved method. The treatment of patients with normal tension glaucoma (NTG) is a very challenging issue since IOP has to be reduced from the high normal to the low normal range, which is separated by a fine line only from hypotony. Since even combinations of multiple antiglaucomatous eye drops fail to reach low target IOP in NTG patients, surgery has to be considered. In this study the effects of non-penetrating deep sclerectomy were evaluated in NTG and POAG patients.
Methods: :
116 patients with medically uncontrollable open angle glaucoma underwent non-penetrating deep sclerectomy. Examinations were carried out directly before and after operation as well as 6 and 12 months after surgery. IOP and the number of antiglaucomatous eye-drops were noted. A statistical analysis with the Pearson’s product-moment correlation coefficient was performed.
Results: :
The IOP was pre-OP 15.9 ± 2.5 mm HG (n=87) in NTG patients and 26.3 ±6 .3 mmHg in POAG patients (n=29), and 12 months after surgery 12.4 ± 2.1 mm HG (n=87) in NTG patients and 13.8 ± 2.8 mmHg in POAG patients. The relative IOP reduction was 20.3% in the NTG group and 45.6% in the POAG group. The correlation of the pre-op IOP and the absolute (= 0.806; p=0,000) and relative (IOP after 12 months - pre-op IOP / pre-op IOP; 0.630; p=0,000) IOP reduction using Pearson’s product-moment correlation coefficient was noted. Pre-op IOP does not correlate with the decreased number of eye-drops 12 months post-op (-0,115; p=0,217).
Conclusions: :
Patients with high pre-op IOP levels showed a higher IOP reduction after deep sclerectomy than NTG patients with low pre-op IOP levels. Therefore, deep sclerectomy can be an effective therapy in POAG. Its success in NTG patients is shown by the number of antiglaucomatous eye-drops that could be reduced significantly in both NTG and POAG. This effect does not depend on pre-op IOP levels, so deep sclerectomy helps reducing the number of eye-drops and thereby soft tissue reactions such as allergies etc. in NTG.