[Peripheral refraction: cause or effect of refraction development?] / Perifericheskaya refraktsiya i refraktogenez: prichina ili sledstvie?

AIM: to study peripheral refraction and the shape of the eyeball in children with different clinical refraction. MATERIAL AND METHODS: Using an original method, peripheral refraction was measured at 10-12 degrees temporally and nasally from the fovea in 56 right eyes with different clinical, or axial, refraction of 20 boys and 36 girls aged 7 to 16 years (11.9±1.17 years on average). The shape of the eyeball was judged of by the ratio of its anterior-posterior axial length (AL) to horizontal diameter (HD). RESULTS: The incidence and value of peripheral myopic defocus in children appeared to decrease with clinical refraction increasing from high hyperopia to high myopia. This was the first time, mixed peripheral refraction was found in children, occurring more frequently in higher myopia. This mixed peripheral defocus, shown to be a transitional stage between relative peripheral myopia and relative hyperopia, indicates non-uniform stretching of posterior pole tissues in the course of refraction development and myopia progression. As ocular refraction increases from high hyperopia to high myopia, the growth of AL outpaces that of HD. CONCLUSION: Obviously, natural peripheral defocus results from changes in size and shape of the eyeball in the course of refraction development.

[Correlation between biomechanical properties of the corneoscleral tunic and stereometric parameters of the optic nerve head in congenital and acquired myopia].

The correlation between biomechanical properties of the corneoscleral tunic and stereometric parameters of the optic nerve head in children and adolescents with congenital and acquired myopia has been studied comparatively. The results showed that in children with high myopia, congenital or acquired, the corneoscleral parameters (scleral echodensity at the equator and the posterior pole, corneoscleral hysteresis, cornea resistance factor, and ocular rigidity coefficient) are lower than those in emmetropes. Moreover, the corneoscleral biomechanical characteristics affect the optic nerve head parameters. This fact has to be taken into account when examining adults with high myopia for the purpose of early diagnostics of glaucoma.

[Acoustic density of sclera as a prognostic factor of peripheral vitreochorioretinal degenerations in myopia: results of 10-years follow-up].

Prognostic value of acoustic density of sclera (ADS) is studied in development of peripheral vitreochorioretinal degenerations (PVCRD) in myopia. Children aged 8-10 years old with noncomplicated high and moderate myopia were divided into two groups after ADS measurement: 1 with ADS < or = 39dB - unfavorable prognosis, 2 with ADS >39dB - favorable prognosis. Follow-up during 10 years with examinations twice a year confirmed prognosis accuracy: in the 1st group PVCRD developed 2.5 times as often as in the 2nd group (64.6 and 25.6% respectively).

[Ocular and orbital blood flow in patients with proliferative vitreoretinopathy associated with rhegmatogenous retinal detachment].

Features of blood flow in ophthalmic artery, central retinal artery, posterior short ciliary arteries were studied using color Doppler mapping (CDM) in 40 patients (40 eyes) with primary rhegmatogenous retinal detachment (RRD) before and after surgery depending on postoperative course. The features of hemodynamic changes were revealed in patients with favorable postoperative course, progression of local and diffuse proliferative vitreoretinopathy (PVR). The risk factors of PVR after surgery were identified. CDM is valuable for predicting of postoperative course after RRD surgery.

[Morphometric and functional features of macula in patients with high congenital myopia].

Combined use of OCT and ERG allowed us to study correlation of functional changes and morphological retinal features in patients with congenital myopia with or without myopic maculopathy. The study revealed the following features of retinal contour in macula region in congenital myopia compared to emmetropia: increase of neuroepithelial thickness in fovea centre, trend to decrease of its thickness in perifoveolar zone, significant (1,7-fold) reduction of neuroepithelial thickness difference between central and pericentral zones and subsequently change of retinal profile. Revealed data should be considered in retinal thickness evaluation of adults with high myopia and in assessment of normal postnatal macula development in children with high myopia. Combination of ophthalmoscopy, OCT and m-ERG may help in early diagnosis and monitoring of progressing macula changes.

[Combined ultrasound study in the prediction of the results of surgical treatment for persistent hyperplastic primary vitreous body in children].

In children with persistent hyperplastic primary vitreous body (PHPVB) concurrent with unilateral congenial cataracts (UCC), combined ultrasound study used to examine blood supply to and hemodynamics of the hyaloid system--a fibrovascular band. To determine the prognosis of a surgical intervention in the mode of color and energy Doppler mapping in the persistent band, retrolenticular membrane, the authors studied whether they had functioning vessels and linear blood flow velocity in different degrees of PHPVB. Based on the results of combined ultrasound study, the authors defined indications for and contraindications to surgical treatment of UCC concurrent with PHPVB in order to prevent hemorrhagic complications (hyphema, hemophthalmos, hyaloid vascular bleeding), as well as the optimal time of surgical treatment.

[Impact of continuous graduated slight myopathic defocusing on postnatal refractogenesis].

Based on today's theories of implication of visual feedback in the regulation of eye growth in postnatal refractogenesis, the authors propose new optical procedures for prevention of myopathy and its progression: continuous graduated slight myopathic defocusing of an image, by using specially chosen plus-lens spectacles. Spectacles for both eyes to be persistently worn were chosen for this defocusing in a risk group of children who had pseudomyopathy, slight or absent hyperopia reserve, and near-sighted parents. In a group of children with mild myopathy, the authors applied their developed and patented method of alternating monolateral defocusing, i.e., alternating distance anisocorrection by means of two pairs of persistently worn spectacles, which were changed every day. The methods were shown to have an inhibiting action on the rise of the anteroposterior axis, a refraction shift towards myopathy; the regular changes in anterior chamber depth and lenticular thickness, which lowered dynamic ocular refraction, were also revealed.

[Role of ultrasonic B-scanning in differential diagnosis and prognosis of the course of optic neuritis]. / Rol' ul'trazvukovogo B-skanirovaniia v differentsial'noi diagnostike i prognozirovanii techeniia opticheskogo nevrita.

The possibility of using ultrasonic scanning in differential diagnosis of optic neuritis (ON) and anterior ischemic neuropathy (AIN) and the prognostic significance of the results were evaluated. The thickness of retrobulbar part of the optic nerve directly behind the eye was measured by echographic B method in patients with ON and AIN. The thickness of the retrobulbar part of the involved and paired optic nerve was more than 0.7 mm in 90% patients with ON, which can be considered as an additional clinical sign of ON. Thickening of the retrobulbar part of the optic nerve is not characteristic of AIN. In patients with disseminated sclerosis ON is associated with less pronounced thickening of the retrobulbar part of the optic nerve than in idiopathic ON, which agrees with the pathogenesis and pathomorphology of disseminated sclerosis. The degree of optic nerve thickening in ON in patients with disseminated sclerosis is prognostically insignificant, while in idiopathic ON more than 2 mm asymmetry of the retrobulbar part of the involved and paired optic nerve is a sign predicting a long course of the disease and maybe incomplete recovery of vision. Thickening of the involved optic nerve by less than 1.7 mm is associated with a better prognosis as regards the time and completeness of vision restoration.

[Reinforcement of the sclera with new types of synthetic materials in progressive myopia]. / Ukreplenie sklery novymi vidami sinteticheskikh materialov pri progressiruiushchei blizorukosti.

The possibility of using a new synthetic material mersilene for scleroplastic operations has been evaluated in experiments and clinical trials were carried out in patients with progressive myopia subjected to sclera fortification. Morphological studies showed the formation of a connective tissue capsule round mersilene; new collagen fibers grow through its cellular structures, thus fortifying the strength of the sclera-graft complex. Clinical results indicate that sclera fortification by a mersilene graft arrested the progress of myopia in almost all (98%) patients by the end of the first year postoperation; by the end of the second year, myopic refraction stabilized in 92% patients. Hence, mersilene transplants are recommended for scleroplasty in progressive myopia.

[Acoustic studies of the sclera in progressive myopia in children and adolescents]. / Akusticheskie issledovaniia sklery pri progressiruiushchei blizorukosti u detei i podrostkov.

Acoustic density of the sclera (ADS) was examined using ultrasonic scanning device Ophthascan-B in 121 eyes of 91 patients aged 9 to 17 with progressive myopia of 3.5 to 14.0 diopters. ADS of the posterior pole and eyeball equator were measured separately. ADS in health was 47.6ë0.24 dB for the posterior pole and 46.0ë0.24 dB for the equator, in myopia 41.7ë0.26 and 38.8ë0.22 d, respectively. ADS in the eyes with myopia developing at school age was reliably higher than in cases with congenital and early acquired myopia. The lowest ADS values for both the posterior pole and equator were detected in patients with high early acquired myopia.

[Possibilities of ultrasound biometry in the differential diagnosis of early melanomas and nevi of the choroid]. / Vozmozhnosti ul'trazvukovoi biometrii v differentsial'noi diagnostike nachal'nykh melanom i nevusov khorioidei.

The authors analyse the results of echobiometry carried out in 21 patients with choroid nevi and in 8 patients with primary melanomas of the choroid, administered no treatment for this or that reason. Nevi with a prominence of less than 1 mm were found to be the most incident, and their elevation did not increase over the course of the follow-up. Only in two patients with nevi these formations were found elevating, this corresponding with the manifestation of clinical signs of primary melanoma. The tumor progress was clearly seen in the patients with primary melanoma of the choroid, it was permanently elevating.