Study finds, Changes of Neuroretinal Rim and Retinal Nerve F
Reduction intraocular pressure (IOP) may generate morphological alterations to the bulb and structure of the retina in individuals with the primary open angle glaucoma (POAG) with filtration surgery. In this study, researchers have assessed changes in the membrane-based parameters of Bruch and the retinal nervous fiber (RNFL) in eyes which have been through Glaucoma filtration operation by means of spectral domain optical coherence tomography.

SD-OCT imaging of the optic nerve head (ONH) and of the RNFL was performed in 54 eyes of 54 patients with medically uncontrolled POAG before and after IOP-lowering surgery (trabeculectomy or deep sclerectomy). The ONH parameter minimum rim width (MRW) and the size of the Bruch’s membrane opening (BMO-Area) were derived from 24 radial B-scans centered on the ONH.

--The average preoperative IOP was 23.1 ± 7.5 mmHg. One month postoperatively, the average IOP decreased to 12.1 ± 4.6 mmHg, which caused a significant increase in the thickness of neuroretinal rim.

--There was no significant change in the automatically detected BMO-Area. The pressure-related increase in MRW correlated well with the postoperative IOP and cup-to-disc ratio (CDR).

--In regression analysis, the alteration in thickness of the neuroretinal rim could be well predicted in a model including CDR, change of IOP and mean deviation (MD) (R2 = 0.414). RNFL showed a significant increase as well.

Finally, IOP-lowering of the ONH parameters induces an increase in thickness in patients with medically uncontrolled POAG in patients. There were no substantial connections with IOP changes and alterations of the RNFL following surgery. In contrast, it is possible to find very important connections between MRWs and the IOP. The BMO area was totally steady.