ABSTRACT
Aim: as a leading cause of blindness worldwide, glaucoma continues to be a clinical problem. In the era of neuroprotection as a new trend in the management of glaucoma today, the demand on more knowledge about the pathogenesis of glaucomatous optic neuropathy [GON] is increasing. So, the aim of our study is to get a deep insight about the role of nitric oxide [NO], and endothelin-l[ET-1] in the pathogenesis of primary open angle glaucoma [POAG]
Method: the present study was carried out on forty subjects of both sexes and different age groups, where they were classified into two groups: group I: Included twenty glaucomatous patients diagnosed as having POAG and scheduled for surgical intervention [subscleral trabeculectomy]; where fourteen patients were selected from those patients attended the Ophthalmology Outpatient Clinic in Minia University Hospital and six patients were selected from those patients attended the glaucoma unit in El-Nour Eye Hospital [Cairo]. The degree of glaucomatous drainage was categorized .according to the clinical state of the optic disc and visual field examination into 4 stages: mild [grade l]; moderate [grade 2]; severe [grade 3] and end stage [grade 4]. The degree of glaucoinatous damage in the examined patients was ranging from moderate to severe. The other group [group II]: Included 20 healthy subjects with senile cataract admitted to the Ophthalmology Outpatient Clinic in Minia University Hospital to do cataract surgery as a control
Results: table 2 shows the demographic and biochemical data of the studied groups, where the results were expressed as mean +/- SD. In addition, it shows comparison of the statistical significance [P- value] of all parameters in the studied groups, where there was highly statistically significant difference in the aqueous levels of NO [p = 0.02] between group I [31.23 +/- 5.29 [micro]Ml/L] and group II [16.42 +/- 2.75[micro]M/L], and on the other hand, there was highly statistically significant difference in the aqueous levels of ET-1 [p = 0.001] between group I [32.47 +/- 3.33 pg/ml] and group II [18.12 +/- 1.9 pg/ml]. Moreover, there was no statistically significant difference as regard age between group I and group II [P= 0.58]. . Table 3 shows Comparison of the statistical correlation coefficient [r] of the aqueous levels of NO and ET-1 between the studied groups where there was a significant positive correlation between aqueous levels of NO and ET-1 in the glaucoma group [P=0.0001]
Conclusion: our results have clearly shown that elevated ET-1 and NO levels in POAG may occur as a response to elevated IOP or the high levels of these parameters could be the cause of glaucoma, so elevated ET-land NO could be a cause or an effect