Stotska L. M.

GI “The Filatov Institute of Eye Diseases and Tissue Therapy of the National Academy of Medical Sciences of Ukraine”, Odesa, Ukraine

Abstract. Glaucoma is a major cause of irreversible vision loss. Modern clinical research methods such as scanning laser polarimetry and optical coherence tomography (OCT), the structural changes recorded on different functional levels of the retina and optic nerve. According to the literature, the structural changes in progressive glaucomatous optic neuropathy ahead the clinical functional manifestations of the disease. In case of OCT of eyes with glaucoma is also recommended to scan the macula with the Quick protocol (Fast Macular Thickness Map). It makes possible to reveal additional information about the disease process.

 Neurophysiological methods (electroretinography) allow to study the processes at various levels of morphological and functional retina, to specify the location and nature of pathological changes in the above structures, to control the dynamics of changes in the structure of the primary lesions in various stages of glaucomatous process.

 Objective. The aim of the study is to examine the state of the peripheral and central vision and carry out their comparative characteristics of patients with primary open-angle glaucoma (POAG) in the context of the bioelectric activity of the retina corresponding levels.

Materials and methods. On the basis of GI “The Filatov Institute of Eye Diseases and Tissue Therapy of the National Academy of Medical Sciences of Ukraine” we have carried out complex clinical and neurophysiological study of 144 patients (274 eyes). Among those were diagnosed 114 people (214 eyes) with the average age of 58.41 + 3.96 years at different stages of POAG (the main group). For diagnosis of a pathological condition it was used a neurophysiological research method – electroretinography, which was carried out on the unit “RETI scan” (Multifocal ERG/VEP, Roland Consult, Germany). 

 Survey results. For the first time when using neurophysiological research method (electroretinography) in patients with POAG it was found the reduction of bioelectrical activity of neurons in the outer and inner layers of the macular area. In a retinogram zone (Rod-Respons, dark phase), in patients with primary and advanced stages of POAG we noted reducing of the amplitude of waves b at 79.35 %, p < 0.05 and 78.88 %, p < 0.05 respectively compared with the control group. According to these data we can confirm that in patients with POAG growth of lesions of peripheral vision occurs by reducing the bioelectric activity of neurons in the inner layer of the retina.

According to our data of rhythmic retinogram (according to the 30 Hz Flicker) we have seen reduction in the amplitude of the peak N1–P1 in patients with primary, advanced and developed stages of POAG at 70.33 %, p < 0.05 and 72.71 %, p < 0.05 and 79.56 %, p < 0.05, respectively, compared with the control group. According to data of 30 Hz Flicker we can find significant lesions of the cone cells in outer layers of the retina macular area at all stages of POAG starting with the primary. 

The most pronounced process we observed in the photoreceptor cells of the outer layers of the retina is the unit of cone in the macular area. When comparing the outer and inner layers of the macular and peripheral portions of the retina we observed significantly defeat at all stages of POAG of inner layer of the retina and the peripheral device of cone photoreceptor of outer layer of the retina in the macular area. Especially it should be emphasized that the power of destruction in these areas at appropriate stages of POAG is almost the same as simultaneous processes that occur at the above levels and areas of the retina. 

 Keywords: peripheral vision, the macula, the retina, electroretinography, primary open-angle glaucoma.

 REFERENCES

1. Resnikoff S., Pascolini D., Etya’ale D., Kocur I., Pararajasegaram R., Pokharel G. P., Mariotti S. P. Global data on visual impairment in the year 2002. Bulletin of the World Health Organization. 2004; (82): 844–851.
2. Quigley H. A., Broman A. T. The number of people with glaucoma worldwide in 2010 and 2020. British Journal of Ophthalmology. 2006; (90): 262–267.
3. Liesegang T. J. Glaucoma: changing concepts and future directions. Mayo Clinic Proceedings. 1996; (71): 689–694.
4. Zavgorodnyaya N., Pasechnycova N. V. Primary glaucoma. A new look at an old problem. Zaporizhia, 2010, 192 p. (in Russian).
5. Stotska L. M., Stotska L. S. Particularly active chromatic optic channels at different stages of primary glaucoma. Oftalmologicheskiy zhurnal [Journal of ophthalmology]. 2013; (6): 22–25 (in Russian).
6. Valladares A. M., Amoros N. P., Cortes A. C., Morollon J. P., Moreno I. F. Validity of ganglion cell-inner plexiform layer thickness measurement in the diagnosis of preperimetric glaucoma: correlation with retinal nerve fiber layer thickness. Proceedings of the 11th EGS Congress (France, Nice, June 7–11, 2014). Nice, 2014, p. 133.
7. Dzhumova M. F., Zhitkevich G. N., Tatur O. N. (2008) Diagnosis of the peripapillary retinal and optic disc nerve fibers lessions in glaucoma optic neuropathy. Oftalmologiya v Belarusi [Ophthalmology in Belarus]. 2009; (1): 192–195 (in Russian).
8. Zeimer R., Asrani S., Zou S., Quigley H., Jampel H. Quantitative detection of glaucomatous damage at the posterior pole by retinal thickness mapping. Ophthalmology. 1998; (105): 544–529.
9. Ojima T., Tanabe T., Hangai M., Yu S., Morishita S., Yoshimura N. Measurement of retinal nerve fiber layer thickness and macular volume for glaucoma detection using optical coherence tomography. Japanese Journal of Ophthalmology. 2007; (51): 197–203.
10. Shamshinova A., Andreeva T. M. Clinical physiology of vision. Moscow, 2006, 956 p. (in Russian).
11. De Zheng W., Yan L. Atlas of testing and clinical application for Roland Electrophysiological Instrument. Beigind Science and Technology Press. 2006; 5–19.

Received: 16 March 2016

Published: July 2016