Objective criteria of neuroprotective glaucoma treatment efficacy

By now, a number of high-tech precise examination methods exist, allowing for a reliable detection of structure and function changes in the optic nerve. They allow performing early glaucoma diagnostics and detecting changes during follow-up. However, the problem of developing comparable criteria of morphofunctional changes according to the data from modern examination methods, usable in clinical practice for patient management, remains a pressing issue.

PURPOSE: To detect and to evaluate additional morphologic and functional criteria of glaucoma stabilization with intraocular pressure (IOP) compensation and neuroprotective therapy use.

METHODS: 27 patients (27 eyes) with moderate and advanced glaucoma stages and compensated IOP were enrolled in the prospective cohort study. The patients underwent a course of Retinalamin treatment (10 intramuscular injections with a second subsequent course after 6 months). Alongside a standard ophthalmologic examination, standard automated perimetry (SAP) (Humphrey Visual Field Analyzer II 750i, Germany), measurement of corneal compensated IOP and biomechanical properties of fibrous eye layer (Ocular Response Analyzer, «Reichert», USA) with consequent evaluation of biomechanic tension, examination of visual cortical potentials (EP-1000 Multifocal «Tomey», Germany) and an ultrasound examination of optic nerve hemodynamics (Voluson 730 РRО, «Kretz», Austria) were performed. The data was statistically analyzed.

RESULTS: We observed normal levels of corneal compensated IOP (11.3-16.9 mmHg) and biomechanic tension coefficient (0.70±0.08) in all patients. SAP data during the course of Retinalamin therapy (except the statistically insignificant changes of photosensitivity) was generally stable. Patients with moderate glaucoma presented with an average photosensitivity increase by 200 dB (8.2%). Electrophysiological studies showed a statistically significant decrease of P100 main component latency and an increase of response amplitude to 1.0° and 0.3° patterns. In most cases ultrasound extraocular hemodynamic examination detected a blood flow enhancement, which was, however, statistically insignificant. The results of blood flow examination correlated with SAP and confocal ophthalmoscopy data.

CONCLUSION: SAP results show positive dynamics of vision functions in patients with glaucomatous optic neuropathy after Retinalamine administration. SAP data conforms to changes in visual cortical potentials. Considering the objectiveness of the method, it can be recommended for vision function dynamic evaluation, especially when SAP is impossible to perform. Duplex ultrasound study of extraocular vessels data correlates with SAP results. This method can also be considered reliable in glaucoma diagnostics.

1. Kritzinger E.E., Beaumont H.M. A colour atlas of optic disc abnormalities. London Chicago: Wolfe Medical Publications; Year Book Medical Publishers, 1987. 118 p.

2. Chen T.C., Wilensky J.T., Viana M.A. Long-term follow-up of initially successful trabeculectomy. Ophthalmology. 1997; 104(7):1120-1125.

3. Flammer J., Orgul S., Costa V.P. et al. The impact of ocular blood flow in glaucoma. Prog Retin Eye Res. 2002; 21(4):359-393.

4. Osborne N.N., Chidlow G., Layton C.J. et al. Optic nerve and neuroprotection strategies. Eye (Lond). 2004; 18(11):1075-1084.

5. Bagrova L.V., Volkov V.V., Verdian E.V. et al. Perimetry methods in algorhythm of glaucoma diagnostics. IV Russian ophthalmology conference: the materials. Moscow; 1994; 211. (In Russ.).

6. Sheremet N.L., Ronzina I.A., Galoyan N.S. et al. Up to date methods of optic nerve evaluation in patients with optic neuropathy of various etiology. Vestn oftalmol. 2011; 127(2):15-18. (In Russ.).

7. Bowd C., Zangwill L.M., Berry C.C. et al. Detecting early glaucoma by assessment of retinal nerve fiber layer thickness and visual function. Invest Ophthalmol Vis Sci. 2001; 42(9):1993-2003.

8. Hougaard J.L., Heijl A., Bengtsson B. Glaucoma detection by Stratus OCT. J Glaucoma. 2007; 16(3):302-306.

9. Cvenkel B., Kontestabile A.S. Correlation between nerve fibre layer thickness measured with spectral domain OCT and visual field in patients with different stages of glaucoma. Graefes Arch Clin Exp Ophthalmol. 2011; 249(4):575-584.

10. Egorov E.A., Kurmangalieva M.M., Fedotovskikh G.V. Morphological study of eyes of glaucoma patients. RMJ Clinical Ophthalmology. 2004; 5(2):54-56. (In Russ.).

11. Onmez F.E., Satana B., Altan C. et al. A comparison of optic nerve head topographic measurements by Stratus OCT in patients with macrodiscs and normal-sized healthy discs. J Glaucoma. 2014; 23(8): e152-156.

12. Egorova I.V., Shamshinova I.V., Erichev V.P. Functional examination methods in glaucoma diagnostics. Vestn oftalmol. 2001; 117(6):38-39. (In Russ.).

13. North R.V., Jones A.L., Drasdo N. et al. Electrophysiological evidence of early functional damage in glaucoma and ocular hypertension. Invest Ophthalmol Vis Sci. 2010; 51(2):1216-1222.

14. Porciatti V. Electrophysiological assessment of retinal ganglion cell function. Exp Eye Res. 2015; 141:164-170.

15. Kozlova I.V. Color doppler imaging in the system of methods of evaluation of the optic nerve head in patients with glaucoma. Glaucoma. 2008; 7(4):69-74. (In Russ.).

16. Avetisov S.E., Bubnova I.A., Antonov A.A. Standard indices of the biomechanical properties of corneoscleral capsule of the eye. Glaucoma. 2012; 10(3):5-11. (In Russ.).