Relationship Of The Disc Damage Likelihood Scale (DDLS), Visual Field And Optical Coherence Tomography (OCT) Parameters For Primary Chronic Angle-closure Glaucoma Optic Neuropathy And Its Clinical Therapy

BackgroundGlaucoma is a characteristic optic neuropathy with progression loss of retina ganglion axons, with vision being deteriorating and even to complete blindness. Glaucoma is the second leading cause of blindness in China, and the most frequent cause is the primary chronic angle-closure glaucoma (PCACG) in Chinese population. It is very important to evaluate the glaucomatous optic neuropathy, during all stage of glaucoma disease, especially during the developing of glaucoma.The cup/disc (C/D) ratio was first introduced by Armaly in the late 1960s, as a standardized method to evaluate the optical nerve. However, the C/D ratio doesn't take into account the variation of rim of disc that represents the true quantity of residual retina ganglion axon passing through the optic disc. The measurement of damage of neuroretinal rim outperforms the C/D ratio in its correlation with visual functionObjective clinical approaches to evaluation the optical nerve head including laser imaging with optical coherence tomography (OCT), Heidelberg retina tomography and scanning laser polarimetry (SLP). They may more accurately reflect the number of ganglion cell axons passing through the optic disc. But they don't take into consideration the neuroretinal rim configuration, disc size or color of optical nerve head (ONH).The glaucoma DDLS is a clinician-based method for codifying focal thinning of the neuroretinal rim and accounts for optic disc size. It is accurate, reproducible, reliable and easy to use. It was approved that the DDLS was a useful parameter in the diagnosis of primary open angle glaucoma (POAG) and it showed a close correlation with visual field, cup/disc ratio and OCT parameters. Furthermore, the DDLS correlates well with global VF loss. Whether it can be used to assess the optic disc damage of PCACG which always encountered in Chinese people or not, it should be tested. A study was performed to investigate the relationship between the neuroretinal rim, as assessed clinically by the DDLS, visual field and various OCT parameters for primary chronic angle-closure glaucoma disorder.Purpose1.To evaluate relationships of the Disc Damage Likelihood Scale (DDLS), global and regional functional loss in visual field (VF) testing, and optical coherence tomography (OCT) parameters for primary chronic angle-closure glaucoma.2.To evaluate the therapy efficiency of DDLS group and the anterior chamber angle closure degree control group.Methods1. Primary chronic angle-closure glaucoma participants were enrolled to assess the DDLS score with a 90-diopters (D) volk len and test with OCT and Swedish Interactive Threshold Algorithm standard 24-2 VF tests with the HFA. The relationships among clinical DDLS score, OCT parameters, and VF values were analyzed by correlation coefficients analysis.2.PCACG patients were divided into DDLS group and anterior chamber angle control group at random. According to the classification of DDLS score and anterior chamber angle closure degree,they accepted laser peripheral iridotomy(PI),PI with IOP anti-drug,and trabeculectomy.The IOP was ananlyzed by logistic regression ananlysis.Results1.Significant correlations were found between the DDLS scores and the RNFL thicknesses at superior, inferior and temporal quadrant (r=-0.673, P=0.0001; r=-0.605,P=0.0001;r=-0.499 P=0.0014). But no correlation was seen between the score with the thickness at nasal quadrant (r=-0.352,P=0.0602). There were significant correlations between the score with the thicknesses at 11,7,6,10 and 12 o'clock positions(r=-0.673,P=0.0001;r=-0.605,P=0.0001;r=-0.531,P=0.0006;r=-0.525,P=0.0007;r =-0.520, P=0.0008), but not with those at 3,2 and 8 o'clock positions (r=-0.320,P=0.0501;r=-0.320,P=0.0510; r=-0.297, P=0.0702). The thicknesses at parameters Avg, Smax and Imax were also correlated with the score (r=-0.582, P=0.0001;r=-0.504,P=0.0012;r=-0.478,P=0.0024).The DDLS showed significant correlation with all of sector OCT area parameters. The highest correlation was with the inferior combined area(r=0.878, p<0.0001). The DDLS score and global MD, PSD were correlated (r=-0.593,P<0.0001, r=-0.60, P<0.0001).2. we apply logistic regression analysis to the DDLS group and anterior chamber angle closure degree group.57 patients were admited, average age was (52.2±10.1)year,There was no stastistically significant between the two groups with laser periperal iridotomy(LPI) therapy method, LPI with IOP anti-drug and trabecultomy(OR=0.81, P=0.624),while trabecultoy is more efficency than two other therapy methods(OR=4.88, P=0.007).Conclusion1.Clinical DDLS assessment on optic nerve damage has a correlation with OCT parameters on RNFL thickness. and visual field. It was approved that the DDLS is a useful method to evaluate the optic neuropathy of primary chronic angle-closure glaucoma.2. clinical DDLS can be used to assess the optic neuropathy, according to the DDLS score and the anterio chamber angle closure degree, PCACG patient can get a right therapy.