[Typical and atypical optic neuritis]. / Tipichnyi i atipichnyi opticheskii nevrit.

Optic neuritis (ON) is one of the most common neuro-ophthalmic causes of vision loss worldwide. Demyelinating ON can be idiopathic or be one of the symptoms of autoimmune demyelinating diseases of the central nervous system (CNS) such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Demographic, clinical and radiological signs of ON in these CNS diseases have differences. In this regard, typical and atypical ON are currently distinguished. Recognizing the clinical features that differentiate typical MS-associated ON from atypical ON in NMOSD and MOGAD is important for choosing the correct disease management and treatment strategy. This review summarizes the data from clinical, laboratory, instrumental methods of management used for the differential diagnosis of optic neuritis.

[Long-term changes in morphological and functional parameters of the optic nerve in patients with various genetic variants of hereditary optic neuropathies]. / Dolgosrochnaya dinamika morfofunktsional'nykh pokazatelei zritel'nogo nerva u patsientov s razlichnymi geneticheskimi variantami nasledstvennykh opticheskikh neiropatii.

Leber's hereditary optic neuropathy (LHON) and autosomal recessive optic neuropathy (ARON) are degenerative diseases of the optic nerve caused by mutations in nuclear or mitochondrial DNA (nDNA, mtDNA). The clinical picture of these diseases is similar, but there are some differences in how the visual functions change in patients with different molecular genetic variants of hereditary optic neuropathies (HON). PURPOSE: This study evaluates the long-term changes in morphological and functional parameters in patients with different genetic variants of HON. MATERIAL AND METHODS: The study included 84 patients (165 eyes) with a genetically confirmed LHON or ARON diagnosis. The patients underwent best-corrected visual acuity (VA) test, color vision (CV) examination, computerized perimetry using the program for low vision assessment, optical coherence tomography (OCT). RESULTS: Over the course of the follow-up (60 months or longer) HON patients were revealed to have higher VA in c.152A>G and m.14484T>C mutations compared to mutations m.11778G>A and m.3460G>A. The final VA 0.5 or higher in patients with c.152A>G and m.14484T>C mutations in 54 and 71% of cases, and only in 6 and 13% of cases - with m.11778G>A and m.3460G>A mutations. Direct correlation was determined between minimal VA in the first year after disease onset and the final VA (K=0.67; p<0.001). In all patients with the investigated mutations CV recovered slightly quicker than VA. CONCLUSION: HON associated with c.152A>G and m.14484T>C mutations have better prognosis compared to LHON caused by m.11778G>A and m.3460G>A mutations. Vision recovery prognosis is worse in patients who had significant decrease of visual acuity at the disease onset. OCT findings reveal preservation of visual functions in all mutations.

[Rare pathogenic nucleotide variants of mitochondrial DNA associated with Leber's hereditary optic neuropathy]. / Redkie patogennye nukleotidnye varianty mitokhondrial'noi DNK, assotsiirovannye s nasledstvennoi opticheskoi neiropatiei Lebera.

Patients with Leber Hereditary Optic Neuropathy (LHON) in most cases have one of the three most common mutations: m.11778G>A in the ND4 gene, m.3460G>A in the ND1 gene, or m.14484T>C in the ND6 gene. According to the international Mitomap database, in addition to these three most common mutations, there are 16 other primary mutations that are even more rare. There are nucleotide substitutions that are classified as candidate or conditionally pathogenic mutations. Their involvement in the disease development is not proven due to insufficient research. Moreover, in many publications, the authors describe new primary and potential mitochondrial DNA mutations associated with LHON, which are not yet included in the genetic data bases. This makes it possible to expand the diagnostic spectrum during genetic testing in the future. The advancements in genetic diagnostic technologies allow confirmation of the clinical diagnosis of LHON. The importance of genetic verification of the disease is determined by the existing problem of differential diagnosis of hereditary optic neuropathies with optic neuropathies of a different origin.

[Optic neuropathies as an interdisciplinary subject of research]. / Opticheskie neiropatii kak predmet mezhdistsiplinarnogo izucheniya.

Despite the wide range of clinical, instrumental and laboratory methods used in modern ophthalmology, the problem of diagnosing optic neuropathy and identifying its etiology remains relevant. A complex multidisciplinary approach involving various specialists is required in the differential diagnosis of immune-mediated optic neuritis, for example in multiple sclerosis, neuromyelitis optica spectrum disorder, and MOG-associated diseases. Of special interest is differential diagnosis of optic neuropathy in demyelinating diseases of the central nervous system, hereditary optic neuropathies and ischemic optic neuropathy. The article presents a summary of scientific and practical results of differential diagnosis of optic neuropathies with various etiologies. Timely diagnosis and early therapy start reduces the degree of disability in patients with optic neuropathies of different etiologies.

[The importance of OCT angiography and Doppler ultrasound methods in diagnosis of optic neuropathies]. / Znachenie opticheskoi kogerentnoi tomografii-angiografii i ul'trazvukovykh dopplerovskikh metodov issledovaniya v diagnostike opticheskikh neiropatii.

This review of literature presents an assessment of circulatory disorders of the optic nerve and the retina in patients with optic neuropathy of different origin by ultrasound and OCTA methods, outlines basic principles of analyzing the state of blood flow in the ocular vessels, and analyzes the results of Russian and foreign research on this topic.

[Multifocal electroretinography in assessment of the functional state of the central retina in patients with retinitis pigmentosa]. / Mul'tifokal'naya elektroretinografiya v otsenke funktsional'nogo sostoyaniya tsentral'noi zony setchatki pri pigmentnom retinite.

Retinitis pigmentosa (RP) is an inherited disease associated with various genetic mutations. Developments in the field of genetic engineering give relevance to the search for methods of studying retinal function, which can prove informative in the selection of patients for treatment. PURPOSE: To evaluate the information content of multifocal electroretinography (mfERG) in the diagnostics of the functional state of the central retina in retinitis pigmentosa (RP). MATERIAL AND METHODS: The study included 115 patients (228 eyes) with PR and 15 people (30 eyes) who comprised the control group. All subjects underwent standard ophthalmological examination, computer perimetry, color vision study, retinal spectral optical coherence tomography, ganzfeld electroretinography (gERG) and mfERG. The relationship between mfERG parameters and the degree of gERG changes, as well as various functional and morphological parameters of the retina was assessed. RESULTS: Visual acuity and perimetry indices varied over a wide range. GERG was unrecordable in 50.4% of cases. MfERG was registered in 214 (98.3%) eyes with varying degrees of change in visual acuity, visual field and gERG parameters. A medium degree positive relationship was revealed between the biopotential density of the retina in the foveal and parafoveal zones and visual acuity (rs=0.68; 0.63), a high degree - between the density of ttotal biopotential of the central retina (DValue) and the average light sensitivity (rs=0.9), a weak degree - between DValue and the thickness and volume of the peripheral retina (rs=0.37; 0.42), a medium negative correlation was found between the average defect in light sensitivity and the biopotential density in the periphery (Rings 4-5) on mfERG, DValue (rs= -0.67; -0.65; -0.69). CONCLUSION: MfERG detects retinal dysfunctions at an early stage of RP, in eyes with high visual acuity, normal parameters of the central visual field and gERG, as well as in low visual acuity, a pronounced decrease in light sensitivity, unrecordable gERG. MfERG can be informative in the selection of patients with RP for gene therapy.

[Autosomal recessive optic neuropathies: genetic variants, clinical manifestations]. / Autosomno-retsessivnye opticheskie neiropatii: geneticheskie varianty, klinicheskie proyavleniya.

Hereditary optic neuropathies (HON) - a group of neurodegenerative diseases characterized by primary loss of structure and function of the retinal ganglion cells and subsequent death of their axons, development of partial optic nerve atrophy. Autosomal dominant optic neuropathy and Leber`s hereditary optic neuropathy until recently were considered the most common genetic hereditary optic neuropathies, while autosomal recessive optic neuropathies (ARON) were described as rare types of HON, usually accompanying severe syndromic pathologies. In the 2000s it has become clear that ARON occur significantly more often, are underestimated, and their clinical variability is poorly studied. Despite the fact that non-syndromic ARON are less common than syndromic optic neuropathies, their contribution to the development of isolated hereditary optic neuropathies should be considered. This article presents a literature review on non-syndromic ARON developing as a result of mutations in the ACO2, MCAT, WFS1, RTN4IP1, TMEM126A, NDUFS2, DNAJC30 genes.

[Leber's hereditary optic neuropathy clinical features in patients with mitochondrial DNA m.13513G>A candidate mutation]. / Klinicheskie osobennosti nasledstvennoi opticheskoi neiropatii Lebera u patsientov s kandidatnoi mutatsiei m.13513G>A v mitokhondrial'noi DNK.

Leber's hereditary optic neuropathy (LHON) is caused by primary mtDNA by both primary mtDNA mutations and new mtDNA mutations. The last ones, when detected in several independent LHON families, receive candidate status. The description of new LHON-associated mtDNA mutation is relevant. PURPOSE: To determine the LHON clinical features in patients with the m.13513G>A mutation and to estimate the patients' proportion with this pathogenic variant in the LHON patients' sample. MATERIAL AND METHODS: The study included 5 LHON patients, associated with m.13513G>A mutation in the ND5 gene in the heteroplasmic state. A standard examination was performed, including color blindness test, visual fields test, spectral optical coherence tomography. RESULTS: LHON, associated with m.13513G>A in the heteroplasmic state in the range of 25-60%, is characterized by visual impairment without additional neurological or other extraocular symptoms. Visual recovery to 0.3-1.0 presents in all patients; the visual recovery onset occurs between 12 and 20 months from the disease manifestation. The decrease of the central scotoma size and its density and the color vision improvement are also observed as well as the average retinal nerve fibers layer and ganglion cell complex thickness decrease. The m.13513G>A mutation frequency is 5% in 100 LHON patients' sample and 22.5% in 22 LHON patients with rare and candidate mtDNA mutations. CONCLUSION: The m.13513G>A mutation can be considered as primary LHON mutation. The list of pathogenic variants recommended for testing LHON can include this mutation. The m.13513 G>A mutation determines the mild LHON course and good visual functions prognosis in these patients.

[Bilateral vision loss on programmed hemodialysis (clinical observation)]. / Dvustoronnyaya poterya zreniya na fone programmnogo gemodializa (klinicheskoe nablyudenie).

The most common complication of hemodialysis is blood pressure decrease, which is an ischemic optic neuropathy risk factor. The article presents a case study of sequential bilateral ischemic optic neuropathy with the development of amaurosis as a result of arterial hypotension against the background of programmed hemodialysis. Differential diagnosis in bilateral visual impairment is discussed.

[Metabolic disorders in hereditary optic neuropathies]. / Metabolicheskie narusheniya pri nasledstvennykh opticheskikh neiropatiyakh.

Folate metabolism disorders are known to have a potential involvement in the pathophysiology of mitochondrial diseases. Many researchers suggest that profound systemic folate deficiency may contribute to mitochondrial folate deficiency. Folic acid metabolism is closely related to vitamin B12 and homocysteine. Considering that hereditary optic neuropathies (HON) are mitochondrial diseases, it is important to study the folate status, the content of vitamin B12 and homocysteine in patients with this pathology. OBJECTIVE: To compare the content of folic acid, vitamin B12 and homocysteine in the blood serum of patients with Leber's hereditary optic neuropathy (LHON) and autosomal recessive optic neuropathy (ARON), optic neuropathy of other genesis, and the comparison group. MATERIAL AND METHODS: The study involved 58 patients with LHON and ARON, the control group of 49 patients with ischemic, inflammatory, traumatic and compressive optic neuropathies, and the comparison group of 20 healthy volunteers. RESULTS: A decrease in blood folic acid levels was revealed (4.0±1.6 ng/mL) in patients with HON compared to the control group (p=1.3·10-8) and the comparison group (p=1·10-17). The content of vitamin B12 in patients with HON was 380.8±168.1 pg/mL, which was significantly lower than in the comparison group (p=0.0001). The homocysteine content was 14.1±5.6 µmol/L in patients with HON, which was significantly higher than in the control group (p=0.0007) and the comparison group (p=0.000003). At the same time, an increase in homocysteine level of more than 10 µmol/L was revealed in 75% of patients with HON. Similar metabolic disorders were found in groups with various mutations in mitochondrial and nuclear DNA. CONCLUSION: Patients with HON showed marked decrease in the levels of folic acid and vitamin B12, as well as hyperhomocysteinemia. It is very important to identify the causes of metabolic disorders in order to determine the role of folate deficiency in the development of HON, as well as the possibility of its pharmacological treatment.

[Electrophysiological and psychophysical studies in assessment of visual functions in patients with hereditary optic neuropathy]. / Elektrofiziologicheskie i psikhofizicheskie issledovaniya v otsenke zritel'nykh funktsii pri nasledstvennoi opticheskoi neiropatii.

PURPOSE: To study the capabilities of electrophysiological and psychophysical examination methods for assessment of the functional state of ganglion cells, retina and optic nerve in patients with hereditary optic neuropathy (HON). MATERIAL AND METHODS: The study included 60 patients (118 eyes) with a genetically confirmed diagnosis of HON. All study patients underwent visual field test (VFT), spectral optical coherence tomography (OCT), flash and pattern visual evoked potentials (VEP) (Flash-VEP, FVEP; Pattern-VEP, PVEP), photopic electroretinography with photonegative response (PhNR) registration and the color vision test. In 24 patients (46 eyes), these parameters were assessed before the start of treatment and one year later. The treatment involved the mitochondria-targeted antioxidant SkQ1 - plastoquinonyl-decyl-triphenylphosphonium bromide (PDTP) in the form of eye drops. RESULTS: The main PVEP components for 1.0° and 0.3° were registered in 20% and in 14% of patient eyes with HON and high visual functions, respectively. After one year of PDTP use, a significant decrease in P100 peak latency was found only in the group with disease duration of ≤1.5 years as of the time of treatment start (p<0.05). Significant differences were observed in the PhNR amplitude (p<0.004) between patients of the main and the control groups, as well as in the PhNR amplitude between patients with visual acuity of ≤0.1 and ≥0.13 (p<0.01). Patients with high visual functions were found to have a correlation between the PhNR amplitude, GCC thickness and the global loss index (GLV). CONCLUSION: Along with VFT, OCT and color vision tests, electrophysiological studies are one of the main methods of examining patients with HON. After one year of PDTP use, there was a significant decrease in the FVEP P2 peak latency in the group with a disease duration of ≤1.5 years as of the time of treatment start. The PhNR amplitude in patients with high visual functions was found to correlate with structural changes in the ganglion cell layer and the retinal nerve fiber layer.

[Clinical and genetic aspects of ABCA4-associated inherited retinal diseases]. / Klinicheskie i geneticheskie aspekty ABCA4-assotsiirovannykh nasledstvennykh zabolevanii setchatki.

The clinical and genetic characteristics of ABCA4-associated inherited retinal diseases have been studied for more than 2 decades, since the identification of the ABCA4 protein in 1978 and the ABCA4 gene in 1997. ABCA4 mutations were initially associated with autosomal recessive Stargardt disease (STGD1). It has now been established that mutations in this gene can cause other inherited retinal diseases, such as cone-rod dystrophy and retinitis pigmentosa. In addition, the phenotypes of ABCA4-associated diseases can vary greatly from the classic presentation of Stargardt disease, from loss of central vision in adolescence to disease with early onset and rapid progression or late onset and milder course. ABCA4-associated diseases are inherited in autosomal recessive manner, i.e. the disease develops only if both alleles of the gene are damaged, one inherited from the father and the other inherited from the mother. As with many other recessive hereditary diseases, which are characterized by a variety of clinical manifestations, the diversity of the phenotypes of ABCA4-associated retinal diseases is explained by combinations of sequence variants in the ABCA4 gene inherited by patients from their parents. Despite the fact that in this respect inherited retinal diseases associated with mutations in the ABCA4 gene do not fundamentally differ from other autosomal recessive traits, due to the structure of the gene and the protein encoded by it, there are a number of features thatshould be taken into account when performing molecular diagnostics, predicting the possibility of manifestation and the course of the disease, and planning the approaches to treatment.

[New possibilities in diagnosis of hereditary optic neuropathies]. / Novye vozmozhnosti diagnostiki nasledstvennykh opticheskikh neiropatii.

The study analyses data from clinical and genetic examination of 114 patients, as well as examination of cytological skin fibroblasts of 20 patients with hereditary optic neuropathy (HON). The clinical examination revealed HON symptoms in all study patients, primary damage of the retinal ganglion cells accompanied by swelling of the peripapillary retinal nerve fiber layer (RNFL) in the acute stage of the disease was observed in 47% of cases. MtDNA mutations that cause the development of Leber hereditary optic neuropathy (LHON) were detected in 73% of cases, including three frequent mutations in 59% of cases, rare and candidate mutations - in 14% of cases; nDNA mutations associated with autosomal dominant optic neuropathy (ADON) - in 6.1% of cases; mutations in the DNAJC30 nDNA gene that caused autosomal recessive optic neuropathy (ARON) - in 21% of cases. Among patients with a clinical picture of LHON, mtDNA mutations were found in 77.6% of cases, while mutations of the DNAJC30 gene of nDNA - in 22.4% of cases. Cytological studies using high-resolution respirometry confirmed the presence of mitochondrial dysfunction not only in the cells of patients harboring pathogenic mutations, but also of those harboring candidate mutations. An algorithm for clinical and genetic verification of HON together with a set of cytological studies allows identification of the mitochondrial genesis of the disease and is indispensable in confirming the pathogenicity of new or candidate mutations.

[Asymmetric form of pigmentary retinopathy (case study)]. / Asimmetrichnaya forma pigmentnoi retinopatii (klinicheskoe nablyudenie).

Unilateral pigmentary retinopathy (PR) is a rare, atypical form of hereditary retinal pathology. Different types of secondary retinopathy associated with various non-hereditary diseases, trauma or intoxication can imitate unilateral PR. Therefore, it is important to determine the cause of visual disorders and differentiate between unilateral and asymmetric PR. The article presents an example of using modern structural and functional diagnostic methods that helped diagnose the asymmetric form of the disease in a patient with suspected unilateral PR.

[Poppers maculopathy (case study)]. / Poppers-makulopatiya (klinicheskoe nablyudenie).

The article presents a clinical case of poppers-associated maculopathy - a maculopathy of toxic genesis, insufficiently represented in Russian scientific literature. The diagnosis was based on anamnestic data (long-term use of poppers), specific structural disorders of the outer layers of the retina in the foveolar zone according to spectral optical coherence tomography, as well as changes in multifocal and ganzfeld electroretinography readings. The main strategy for patients with this disorder is complete rejection of poppers.

[Possibilities of an experimental damaging effect on the retinal pigment epithelium]. / Vozmozhnosti eksperimental'nogo modelirovaniya povrezhdayushchego vozdeistviya na pigmentnyi epitelii setchatki.

PURPOSE: To simulate the damaging effect on retinal pigment epithelium (RPE) in an experiment studying the effect of human neuronal precursors (NPs). MATERIAL AND METHODS: The study was carried out on 31 rabbits (31 eyes) of the Chinchilla breed, which were divided into 3 groups: the 1st group received a subretinal injection of balanced saline solution (BSS); the 2nd group - subretinal injection of BSS with vitrectomy, displacement of the injection bladder away from the injection site using a perfluororganic compound (PFOC) and laser coagulation; the 3rd group - subretinal injection of a culture of NPs using the same method as in the group 2. All rabbits were observed for 21 days using ophthalmoscopy, optical coherence tomography (OCT) and autofluorescence (AF). RESULTS: In the 1st group, 4 out of 5 rabbits were observed to have total retinal detachment and vitreoretinal proliferative processes in the early postoperative period after subretinal injection of the BSS. In the 2nd group, OCT and AF revealed atrophy of the outer and inner layers of the retina as well as disorganization of the photoreceptors-RPE-Bruch's membrane complex in the area of injection on the 21 day after the operation. In the 3rd group, the OCT data obtained during the 21 days of observation showed that a hyperreflective zone at the level of the RPE-Bruch's membrane complex corresponding to the NPs injection site was preserved, while there was a partial loss of the outer retinal layers - but of a smaller volume compared to the BSS injection. The suggested method of subretinal injection led to a reduced number of complications: in the 1st group, postoperative complications amounted to 80%, while in the 2nd and 3rd groups - 45%. CONCLUSION: The study proposes a new method for retinal injection of BSS, which can help reduce RPE degeneration patterns and possible postoperative complications, thus increasing research efficiency. Subretinal injection of a culture of neuronal precursors derived from human induced pluripotent stem cells (iPSCs) in an experiment can serve as a universal model for studying the survival and integration of stem cells.

[New possibilities in the treatment of Stargardt disease]. / Novye vozmozhnosti terapii bolezni Shtargardta.

Stargardt disease is a hereditary retinal dystrophy associated with mutations in the ABCA4 gene. Currently, no etiopathogenetic drugs nor treatment methods for Stargardt disease have completely passed clinical trials. The review summarizes experimental and clinical studies of drugs aimed at reducing the accumulation of vitamin A dimers, lipofuscin, complement inhibition and RPE regeneration by stem cell transplantation, as well as gene therapy studies with intravitreal vector injection of the ABCA4 functional gene.

[Structural and functional changes in the retina and optic nerve in patients with toxic optic neuropathy caused by acute methanol poisoning]. / Osobennosti strukturnykh i funktsional'nykh izmenenii setchatki i zritel'nogo nerva u patsientov s toksicheskoi opticheskoi neiropatiei na fone otravleniya metanolom.

PURPOSE: To identify the specifics of structural and functional changes in patients with toxic optical neuropathy caused by acute methanol poisoning. MATERIAL AND METHODS: One female patient with toxic optic neuropathy (TON), 2 male patients with partial optic atrophy caused by methanol poisoning, and 1 male patient with methanol intoxication after ethanol containing alcohol use were examined with kinetic perimetry and optical coherence tomography. RESULTS: Patients with TON caused by acute methanol poisoning were observed to have decreasing visual acuity to the extent of complete blindness. OCT follow-up studies revealed thinning of the retinal nerve fiber layer (RNFL) as well as formation of microcysts in the inner retinal layers, destruction of ellipsoid zone and outer segments of photoreceptors. The patient with methanol intoxication after use of ethanol containing alcohol had retained his visual functions; he was found to have microcysts and RNFL thinning during the first few months after the intoxication, but they were within normal range of OCT parameters. CONCLUSION: Patients with TON caused by acute methanol poisoning are common to have optic atrophy with either residual visual functions or complete blindness as well as microcysts formation, structural changes and destruction of the ellipsoid zone and outer segments of photoreceptors. In patient with methanol intoxication after use of ethanol, which is known to be an antidote, complete visual recovery was observed, although some microcystic changes and ganglion cells layer thinning were noted.

[Characteristics of changes in retinal and optic nerve microvascularisature in Leber hereditary optic neuropathy patients seen with optical coherence tomography angiography]. / Osobennosti mikrososudistykh izmenenii setchatki i zritel'nogo nerva u patsientov s nasledstvennoi opticheskoi neiropatiei po dannym opticheskoi kogerentnoi tomografii-angiografii.

PURPOSE: To investigate the features of various parameters of the density of retinal blood vessels, optic nerve head (ONH) and peripapillary region in hereditary optic neuropathy (HON) patients revealed with optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: The study included 29 HON patients divided into three groups based on symptoms duration (less than 1 year; 1-5 years, more than 5 years) and visual acuity (0.5-1.0; 0.04-0.4; 0.03 and lower). Relative macular, optic disc and peripapillary vessel density (VD, %) was assessed by OCTA (xR Avanti, Optovue Inc., USA). RESULTS: Significant progressive VD reduction in superficial capillary plexus (SCP) was detected in all parafovea sectors and in the temporal sector of perifovea over the course of disease progression. No significant differences of these parameters were found in correlation with visual acuity. Patients with VA of 0.5-1.0 turned out to have greater VD in deep capillary plexus (DCP), whereas no differences were found in relation to the duration of HON. A strong significant correlation between the SCP and DCP VD only in central foveal area was revealed in all groups depending on the VA and symptoms duration. Over the course of HON progression, VD in the temporal sector and in temporal segments of superior and inferior sectors has gradually reduced. In patients with VA of 0.5-1.0, the retinal nerve fibers layer (RNFL) thickness in the temporal sector and optic nerve VD was notably greater compared to patients with lower VA. The most significant correlation was established between VA and structural changes (K=0.75, p<0.001) and VD in the temporal sector (K=0.57-0.61, p<0.001). CONCLUSION: The obtained data suggest that derivative microvascular changes play an active role in the clinical progression of the disease.

[Morphological and functional indicators of retinal pigment epithelium and photoreceptor apparatus in inherited retinal diseases]. / Morfofunktsional'nye pokazateli retinal'nogo pigmentnogo epiteliya i fotoretseptornogo apparata pri nasledstvennykh zabolevaniyakh setchatki.

PURPOSE: To evaluate the relationship between the morphological and functional parameters of retinal pigment epithelium (RPE) and photoreceptors (PR) in inherited retinal diseases (IRD). MATERIAL AND METHODS: The study included 52 patients (104 eyes), 23 of them with Stargardt Disease (STGD), 19 with cone-rod dystrophy (CRD), 10 with retinitis pigmentosa/pigmentary abiotrophy (RP) of comparable disease durations. All patients underwent standard and additional ophthalmological examination: fundus autofluorescence (AF), spectral optical coherence tomography (OCT), computer perimetry (CP), electro-oculography (EOG), Ganzfeld electroretinography (gERG). RESULTS: Comparison of the groups of IRD patients and groups according to the degree of RPE damage with the control group revealed an increase in differences in the EOG and gERG indicators as the area and depth of damage to the RPE and PR progressed. The patterns of changes in RPE and PR, the frequency of their occurrence with IRD in this patient sample are described. A moderate correlation was found between the amount of RPE loss and EOG light rise, as well as between the defect of the ellipsoid zone and the amplitude of α- and ß-waves, the latency of ß-wave of the gERG. Some patients showed a mismatch between a small defect of the ellipsoid zone and RPE with significant damage to the visual field and reduction of the EOG and gERG indicators. The obtained electrophysiological indicators revealed pathological changes in RPE and PR, more significant and widespread in some cases than it was shown with visualization methods. Weak and moderate correlations between visual acuity, and RPE damage and light sensitivity index with loss of ellipsoid zone were calculated. CONCLUSIONS: Modern methods of retinal examination can help obtain complete and versatile picture of morphological and functional state of the retina in IDR that supplement each other. EOG and gERG have capability to determine the degree of RPE and PR functions impairment including those cases when morphological studies are not sufficiently informative.