SU1664278A1 - Method for determining contraindications for executing operation concerning refraction anomaly in children - Google Patents

Abstract

This invention relates to ophthalmology. The purpose of the invention is to improve the accuracy of the method. The conclusion that operations are not feasible is done when receiving visual evoked potential with violation of the polarity of the peaks (P), reducing the number of peaks and changing the latency of one or several peaks. 10 il.

Description

The invention relates to medicine, and more specifically to ophthalmology, and can be used in the surgical correction of myopia, hyperopia and various types of astigmatism in children.

The purpose of the invention is to improve accuracy.

FIG. 1-10 graphically depicted evoked potentials.

The method is carried out as follows.

The patient determines the anatomical parameters of the eye (corneal refraction, clinical refraction of the eye, corneal thickness and diameter, eye length, eidothelial cell density) and functional parameters (visual acuity without correction and correction, retinal acuity and lability, electroretinography) .

Then, when obtaining the parameters that are indications for surgery (high degree astigmatism, anisometropia

high degree), proceed to the study of visual evoked potentials.

The study of VEP in children aged 5 years and older is carried out as follows. The patient is placed in a comfortable chair with a lift to adjust the height in a shielded room in front of the photostimulator. The head is fixed on the chin rest. Electrodes are applied in the usual way: the active electrode is placed on the occipital region of the head 2-3 cm above the bone occipital articulation inion in the midline and fixed with a rubber helmet, the indifferent electrode is placed on the earlobe, the grounding electrode is placed on the forehead. The study was performed monocularly under mesopic conditions, the illumination at eye level was 19 lx, upon presentation of stimuli in the form of flashes of light (characteristics of flashes: power 0.36-0.4 J, frequency of 1 Hz, number 50).

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When recording the potential, 50 responses of the visual cortex are summed up, an analysis era of 512 ms. The VEP is recorded at the X-Y recorder.

In the graphic image of the VIZ, there are 4 main potential peaks, which are identified by polarity, latency and amplitude.

In the case of an adult type of VSP, the complex distinguishes the first peak (1) - negative with latency (ti) 56-70 ms and amplitude, on average 2-7 μV, the second peak (2) - positive with latency (t2) 90-110 ms and an amplitude of 7-19 mV, the third peak (3) is negative with a latency (ta) of 140-150 ms and an amplitude of 6-18 μV, and the fourth peak is positive with a latency (t4) of 180-200 ms and an amplitude of 5-15 μV.

Along with the described, so-called adult type of SGP, a children's type of potential is recorded, which is characterized by the presence of three peaks: the first peak (1) is negative with a latency (ti) of 56-70 ms and an amplitude of 0.5-10 μV, the second peak (2) positive with latency (t2) 110-150 ms, prevailing in amplitude, the magnitude of which varies between 15-30 μV, and the third negative peak (3) with latency (1z) 170-180 ms and amplitude 15-25 μV . Peak count, latency and polarity are measured.

If the child has a childish type of VEP: the complex of which consists of three peaks, the first peak being negative with a latency of 56-70 ms, the second peak is positive with a latency of 110-150 ms, and the third peak is negative with a latency of 170-180 ms, if the operation is considered to be shown.

The operation is carried out even if the patient has an adult type of VIZ with the number of peaks in the complex not less than four, the first peak should be negative with latency within 56-70 ms, the second peak - positive with latency of about 90-110 ms The third peak is negative with a latency of 140-150 ms and the fourth peak is positive with a latency of 180-200 ms.

When the polarity of one or several peaks of the child or adult VEP complex changes, the operation is not performed, because in the process of examining children and adolescents with similar changes, disturbances in the functions of the central region of the retina (dystrophic changes of congenital and acquired nature) were detected. findings of the previous ophthalmologic examination and were confirmed

specially appointed additional methods (angiography).

If, when measuring the number of peaks in the VEP complex, it is said that when

Children’s types will have less than three, and if they receive an adult type, there will be less than four peaks. In this case, the operation is considered contraindicated, as it is empirically noted that children with a decrease in the number of peaks have dysfunctions of the central parts of the visual analyzer ( the consequences of postnatal hemorrhage are either underdevelopment of the structures responsible

5 for the analysis of visual images) that cannot be detected by routine ophthalmologic examinations.

In the event of a change in the latency of one or more peaks of the children's complex

0 Or an adult type of VEP in the direction of increasing or decreasing by more than 25 ms. the operation was not carried out. During the survey it was noted that the violation of the latency of the VEP complex may indicate

5 on impairment of the functions of the conductive paths (partial optic nerve atrophy, consequences of inflammatory diseases of the brain membranes and nerves are possible), and during ophthalmoscopy of the fundus of the optic nerve atrophy it can not always be diagnosed, since the optic nerve disc may not altered, even more difficult to diagnose the effects of inflammatory

5 diseases of the membranes of the brain and nerves, which can be detected only with special targeted neurological examinations.

The research is carried out in the following

0 condition: the distance from the eye to be examined to a flash of light is 30 cm; the study was conducted under the conditions of selected correction for near; registration of the VIZ was performed monopolistically, the active electrode

5 was located 2.5-3 cm above the occipital articulation area of the inion, an indifferent electrode on the ear lobe; the contralateral eye is closed with a dark patch; stimulation was carried out in the light

0 flashes of white light with an intensity of 0.4 J with a frequency of 1 Hz, the angular size of the stimulus is 20 °; In addition to diffuse flashes of light, structured stimuli in the form of chess fields were used. Corner

5, the dimensions of the cells of the chess fields varied and were 12, 24, 36, 48, 60, 90, and 120 angular minutes; psychotherapeutic training was previously carried out to ensure the child's calm behavior during the study.

Example 1. Patient A., aged 14, was admitted with complaints of rapid visual fatigue, pain in the eye area when reading, intolerance to spectacle correction.

Clinical diagnosis: complex myopic astigmatism of a high degree, refractive amblyopia of a moderate degree in both eyes.

Survey data. Right eye: visual acuity of 0.03 8RI-4, OD, 5D ax 85 ° 0.4, cornea refraction 90 ° - 45.5D, 0 ° - 41.25D, eye length 24.85 mm, cornea thickness in the center 520 microns, . Left eye: visual acuity of 0.03 sph-3,5fl, 75D ah, 6, corneal refraction 82 ° -45.25 D, 172 ° -41, OD, eye length 24.79 mm, cornea thickness at the center 520 microns,.

In the study of the VEP in both eyes, an adult type of VEP was recorded with well pronounced 5 peaks of the complex. On the right eye, the first peak (1) is negative with latency (ti) 50 ms and amplitude 4 μV, the second pi (2) is positive with latency (ta) 85 ms and amplitude 6 μV, the third peak (3) is negative with latency (ta) 40 ms and an amplitude of 16 µV, and the fourth peak (4) is positive with a latency (t4) of 180 ms and an amplitude of 25 µV (FIG. 1). In the left eye, the first peak is negative with a latency of 56 ms and an amplitude of 7 μV, the third peak is negative with a latency of 145 ms and an amplitude of 19 μV, the fourth peak is positive with a latency of 185 ms and an amplitude of 24 μV. Conclusion: in both eyes, an adult type of VEP with a normal number of peaks, with their correct alternation without disturbing latency (an increase in the amplitude of the fourth peak is regarded as a variant of the norm).

The patient underwent anteriorly dosed tangential keratoma in both eyes. Examination 6 months after surgery: right eye: visual acuity 0.1 zrp-4, 9, corneal refraction 90 ° - 43.25 D, 0 ° - 42.25 D, eye length 24.84 mm, cornea thickness at center 520 microns , As a result of the operation, the corneal astigmatism decreased from 4.25 to 1.OD, and the visual acuity without correction increased from 0.03 to 0.1, and with a correction from 0.4 to 0.9, in addition, the conditions for correction improved - instead of spherocylindrical it became simple spherical.

Left eye: visual acuity of 0.2 with sph-4, 9, cornea refraction 80 ° -43.5 D, 170 -42.75 D, eye length 24.81 mm, cornea thickness in the center 520 microns,. As a result of the operation, corneal astigmatism decreased from 4.25 to 0.75 D, and

Vision without correction and with correction increased from 0.03 to 0.2 and from 0.4 to 0.9, respectively.

Thus, as a result of the operation

good optical and functional results were obtained.

Example 2. Ill L., 8 years old, was admitted with complaints about the lag of the right eye in the act of vision, rapid fatigue. The clinical diagnosis is a high degree mixed astigmatism, a refractive amblyopia of a high degree of the right eye. Simple astigmatic anisometry.

Survey data. Right eye: os5 trophin of sight 0.2 does not correct, corneal refraction 92 ° - 47.75 D and 2 ° - 44, OD, eye length 22.56 mm, cornea thickness in the center 550 microns,.

Left eye: visual acuity without correction 1.0, corneal refraction 90 ° - 45.5 D and 0 ° - 45.25 D. The nature of the sight is simultaneous. Stereo vision is absent.

In the study of the VEP in both eyes, a children's type of VEP was registered. In the right eye, the signal has 3 peaks, the first peak (1) is negative with latency (ti) 55 ms and amplitude 8 μV, the second peak (2) is positive with latency (t2) 150 ms and amplitude 34 μV, and the third negative peak (3) with latency (t) of 180 ms and an amplitude of 9 μV (Fig. 2). A signal with similar parameters was recorded on the left eye. Conclusion: the children's type of VEP with the normal number of peaks, with their correct alternation

5 without violation of latency (an increase in the amplitude of the 2nd and 3rd peaks is regarded as a variant of the norm).

The patient was made with T-keratotomi on the right eye. The operation and the postoperative period are without complications.

After 1 g after surgery, the visual acuity of the right eye without correction 1.0, corneal refraction 90 ° - 45.5D and 0 ° - 45.0D, eye length 22.61 mm, cornea thickness in

5 center 560 microns, binocular character of vision, 40 sec stereo. As a result of the operation, corneal astigmatism decreased on the right eye from 3.75 to 0.5 D, and the visual acuity increased 5 times and became

0 equal to 1.0. Binocular functions normalized.

PRI me R 3. Sick H., 7 years old, was admitted with complaints of low visual acuity in both eyes.

5 Clinical diagnosis: complex myopic astigmatism of high degree, refractive amblyopia of moderate degree in both eyes.

Survey data. Right eye: visual acuity of 0.08 sr-2.5D .0D ah

87 ° -0.2, corneal refraction 100 ° -47.25 D and 10 ° -42.25 D, eye length 24.42 mm, thickness of the cornea in the center 560 microns,. Left eye: visual acuity of 0.08 with sr-2.25 D, OD ah, 2 cornea refraction 82 ° - 47.0 D and 8 ° - 42.5 D, eye length 24.50 mm, cornea thickness in the center 560 microns, PEC-2900 .

In the ophthalmology of the fundus of both eyes: the optic nerve disc is pale pink with clear boundaries, the initial narrow myopic cone, the macular area with no visible pathological changes, the caliber of the vessels is normal, and focal changes are not observed.

In the study of the SGP in both eyes, an adult type of SGP was detected, in the complex of which 3 peaks were identified, the first peak (1) is positive, the second peak (2) is negative, the third peak (3) is positive, i.e. there was a measurement of the polarity of the three peaks of the ZLL complex, the fourth peak was absent. The latency of the three peaks was within the lower permissible limit of the norm, respectively 30.70 and 120 ms (Fig. 3).

The patient underwent anteriorly dosed tangential keratotomy. Surgery and postoperative period without complications. Survey data 6 months after surgery. Right eye: visual acuity of 0.2 srp-3, 2, refraction 102 ° -45, OD and 12 ° -44, OD, eye length 24.48 mm, cornea thickness in the center 560 microns,. Left eye: visual acuity of 0.2 with spri-3,5fl, corneal refraction 90 ° - 45, OD and 0 ° - 44.25 D, eye length 24.51 mm, cornea thickness in the center 560 microns,. As a result of the operation, corneal astigmatism in the right and left eyes decreased from 5.0 and 4.5 to 1.0 and 0.75D, respectively. Despite the complete refractive success of the operation, the visual acuity with correction on the right eye remained unchanged, on the left eye it increased by 0.1, although the conditions for correction improved. To clarify the reason for such a low functional outcome of the operation, the child was assigned an additional examination and using contrast angiography, a congenital dystrophy of the retina was detected. Thus, the correct interpretation of the parameters of the VEP before the operation would make it possible to correctly diagnose and not to carry out an inexpedient operation.

PRI me R 4. Ill., 6.5 years old, complained of low visual acuity

Both eyes are wearing glasses, intolerance to hard contact lenses. Clinical diagnosis: complex myopic astigmatism

high degree of both eyes. Survey data. Right eye: visual acuity of 0.1 s 8pH-4, OD, 5D ah 90 ° - 0.2, corneal refraction 90 ° - 43.5D and 0 ° - 40.5D, length

eyes 25.51 mm, thickness of the cornea in the center 495 microns,. Left eye: visual acuity of 0.1 zrp-3, OD, 5D ah, 2, corneal refraction 90 ° - 43.25 D and 0 ° - 40.5 D, eye length 25.27 mm, thickness of the cornea in

0 center 498 microns,. Ophthalmoscopy of the fundus of both eyes: optic nerve disk pale pink with clear boundaries, myopic cone 1 / HPD, macular area without visible pathological changes, reflex from the macular area preserved, vessel gauge unchanged, focal pathology not marked.

In the study of the SGP in both eyes, a children's type of SG was registered,

0 complex of which 3 peaks were identified, the first peak (1) was positive with a latent period (ti) - 58 ms and an amplitude of 10 μV, the second peak (2) was negative with a latent period (ta) of 102 ms and an amplitude of 5 μm and 24 μV , the third peak (3) is positive with a latent period (ta) of 180 ms and an amplitude of 18 μV (Fig. 4).

Conclusion: in both eyes, the children's type of VEP with a normal number of peaks

0 and normal latency and peak amplitude. A change in the polarity of all three peaks is noted.

The patient underwent anteriorly dosed tangential keratotomy.

5 Surgery and postoperative period without complications. Survey data 6 months after surgery: right eye: visual acuity 0.1 sph-6, 2, corneal refraction 92 ° - 42.1 D and 2 ° - 42.2D, eye length 25.6

0 mm, the thickness of the cornea in the center 490 microns,. Left eye: visual acuity of 0.1 s 8rpb, 5D 0.3, cornea refraction 90 ° - 42.0D and 0 ° - 42, OD, eye length 25.3 mm, cornea thickness in the center 492 microns,

five . There is no change in the fundus of the eye. As a result of the operation, the corneal astigmatism in both eyes was completely corrected and became equal to zero. Despite the full refractive effect of the surgery, the visual acuity without correction did not change, but with correction it increased by 0.1 only in the left eye, and in the right eye did not change. The conditions of correction as a result of the operation improved in both eyes.

5 In order to identify the cause of the lack of a functional effect of the operation on the right eye and a low functional effect on the left, an additional examination was prescribed for the child and with the help of contrast angiography

congenital anomalies of development of the maculae of the pry region of both eyes Thus, the correct estimation of the parameters of the SGP, namely the polarity of the SGP peaks before the operation, would allow making the diagnosis correctly and not performing an inexpedient operation.

Example 5. Patient P., 6 years old, was admitted with complaints of low visual acuity with sphero-cylindrical correction, rapid fatigue. Clinical diagnosis: complex myopic astigmatism of a high degree, refractive amboliopi of a moderate degree in both eyes. Survey data. Right eye: visual acuity of 0.05 sph-4,0fl ,, 2, corneal refraction 82 ° - 48, OD and 2 ° - 43.5D, eye length 23.6 mm, cornea thickness in the center 500 microns,, ERG-norm . Left eye: visual acuity of 0.05 with sph-4.0, OD ah 85R - 0.2, eye length 23.65 mm, the thickness of the cornea in the center is 510 microns,, ERG is the norm. When ophthalmoscopy of the fundus of both eyes: the optic nerve disk is pale pink with clear boundaries, the macular area and the vessels are unchanged, on the periphery there is a moderate redistribution of the pigment.

In the study of the SGP in both eyes, an adult type of SGP was detected, in the complex of which 3 peaks were identified, and there was no second peak (2), which normally should have been positive. The rest are the first peak (1) negative with latency (ti) 50 ms and amplitude 5 μV, the third peak (3) negative with latency (ta) 140 ms and amplitude 4 μV and the fourth peak (4) positive with latency (m ) 175 ms and an amplitude of 9 μV (Fig. 5).

Conclusion: in both eyes, the adult type of VEP with a decrease in the number of peaks to 3 (there is no second peak of the complex). The polarity, latency and amplitude of the peaks are normal.

The patient underwent anteriorly dosed keratotomy to correct corneal astigmatism. Surgery and postoperative period without complications. Survey data 5 months after surgery. Right eye: visual acuity of 0.08 sph -5,, 3, corneal refraction 90 ° - 46.8D and 0 ° - 45.8D, eye length 23.69 mm, cornea thickness in the center 508 microns,, ERG-norm. When ophthalmoscopy of the fundus of the eye is not observed. In the ultata operation, corneal astigmatism decreased from 4.0 to 1.0 D, i.e. became within normal limits, and conditions of correction improved. However, the functional effect was significantly lower than in other

cases, and visual acuity with correction increased only by 0.1. To clarify the reasons for such a low functional effect of the operation on both eyes of the child

An additional examination was scheduled. As a result of a complex neurological examination, changes in the visual cortex have been identified, which is a consequence of postpatal

0 small focal hemorrhages. Thus, correct assessment of the parameters of the VEP, namely reducing the number of peaks of the complex of VEP before the operation, would allow the child not to perform an inexpedient operation, but to send him for examination and possible treatment by a neuropathologist.

PRI me R 6. Patient B., 8 years old, was admitted with complaints of low visual acuity with glasses, rapid fatigue. Clinical diagnosis: complex myopic astigmatism of a high degree, refractive amblyopia of a high degree in both eyes. Survey data. Right eye: visual acuity of 0.01 sph -2, OD cyl -4,, 1, pe5 corneal fraction 98 ° -45.5D and 8 ° - 40.25D,

eye length 24.7 mm, the thickness of the cornea in

 center 525 microns, ERG - the norm. Left

eye: visual acuity 0.01 sr-2.25 D cyl 4 ,, 1, corneal refraction 90 and - 45.7 D

0 and 0 ° -41, OD, eye length 24.55 mm, the thickness of the cornea in the center of 520 microns,, ERG - the norm. The ophthalmoscopy of the fundus of both eyes showed the presence of an initial myopic cone, the macular area and

5 vessels are normal. In the study of the SGP in both eyes, a children's type of SG was registered, in the complex of which the second (2) positive peak was reduced. The first (1) peak - negative had a normal latency (ti) of 65 ms and an amplitude of 18 µV. The third (3) peak - positive also had a normal latency (gz) of 185 ms and an amplitude of 5 µV.

Conclusion: in both eyes children

5 type of SGP with the reduction of the second peak and with the normal characteristics of the first and third complex of the SGP.

In order to correct a complex myopic astigmatism of a high degree, the patient underwent anteriorly dosed tangential keratotomy in both eyes. Surgery and postoperative peri-Od without complications. Survey data 6.5 months after surgery: right eye:

5 visual acuity 0.08 sph -3 ,,, 3, corneal refraction 98 ° - 43.5D and 8 ° - 42.5D, eye length 24.9 mm, cornea thickness in the center 520 microns,, ERG is the norm. Left eye: visual acuity 0.08 sph - 3,, 3, corneal refraction 90 ° -43.2 D

and 0 ° - 42.2D, eye length 24.77 mm, corneal thickness at the center of 520 microns,, ERG is the norm. When ophthalmoscopy of the fundus of the eye of the eye of a fresh change is not detected. As a result of the operation, corneal astigmatism decreased from 5.25 to 1 in the right eye, and from 4.7 to 1 in the left eye, and the OD began to meet the norm. However, despite the high refractive effect of the operation, the functional - the same as in other cases: visual acuity with correction in both eyes increased by only 0.2. In order to identify the cause of such a functional result of the operation, the child was assigned an additional examination. As a result of a comprehensive neurological examination, an underdevelopment of some parts of the CNS was established. Thus, the correct assessment of the parameters of the EEC, namely, the reduction in the number of peaks of the VEP complex before the operation, would allow the child not to perform an inexpedient operation, but to examine him purposefully at a neuropathologist.

PRI me R 7. Patient I., 6.5 years. He complained about the low sharpness of his eyes in both eyes with glasses, intolerance to spectacle correction, which was prescribed by the doctor at the place of residence. Clinical diagnosis: complex myopic astigmatism of a high degree, refractive amblyopia of a high degree in both eyes. Examination data: right eye: visual acuity of 0.01 with sph -6.75D cyl-4, OD ah, 1, corneal refraction 94 ° - 44 ° 75D and 4 ° - 41.75D, eye length 25.8 mm, cornea thickness in the center of 510 microns,. Left eye: visual acuity of 0.01 with sph -6, OD cyl -4.5D ax, 1, corneal refraction 82 ° - 45.5D and 4 ° - 41.75D, eye length 25.9 mm, corneal thickness in the center 500 microns ,. When ophthalmoscopy of the fundus of both eyes, the optic nerve head is pale pink, the boundaries are clear, the myopic cone is 1/2 DD, the vessels are normal, the redistribution of pigment in the macular area and on the periphery. In the study of VEP in both eyes, an adult type of VEP was recorded, having four peaks with the correct orientation, however, a decrease in latency (t2) of the second (2) positive peak to 30 ms, having a normal amplitude of 8 μV and a third (3) negative peak, latency (gz) which is reduced to 50 ms, although its amplitude remained within the normal range of 30 μV. The fourth (4) peak is positive, has a normal latency (t4) of 115 ms and a normal amplitude of 15 μV (Fig. 7).

Conclusion: in both eyes, the adult type of VEP with the correct orientation of all

four peaks with a normal amplitude, but a violation of the latency of the second and third peaks.

For the correction of complex myopic astigmatism of a high degree, the patient underwent anteriorly dosed tangential keratotomy in both eyes. Surgery and postoperative period without complications. Survey data 4.5 months after surgery. Right eye: visual acuity of 0.02 sph -8, 1, corneal refraction 94 ° - 43, OD and 4 ° - 42.5 D, eye length 25.82 mm, cornea thickness at the center 500 microns,. Left eye: visual acuity of 0.02 sph-7, 1 corneal refraction 80 ° - 43, OD and 10 ° - 42.5 D, eye length 25.95 mm, cornea thickness in the center 500 microns,. With eye fundus ophthalmoscopy, no new changes were noted. As a result of the operation, corneal astigmatism in the right eye was reduced from 3.0 to 0.5D and in the left eye from 3.75 to 0.5D. Despite the high refractive effect of the operation, the functional effect was not obtained - visual acuity with correction in both eyes remained unchanged. To clarify the reasons for the lack of a functional effect, the patient was prescribed an additional examination. With the help of computed tomography, partial atrophy of the optic nerves of congenital character was revealed. Thus, a correct assessment of the parameters of the VEP, namely reducing the latency of the second and third peaks, would not allow the child to carry out an inexpedient operation, but to examine it purposefully and apply other treatment methods.

Try on Patient T., 14 years old, was admitted with complaints of low visual acuity of the right eye, intolerance of spectacle correction, headaches. Clinical diagnosis: mixed astigmatism of a high degree, refractive amblyopia of a high degree of the right eye, simple astigmatic anisometropia. Survey data. Right eye: visual acuity of 0.01 5rp + 4, OD cyl-8.0D ax, 1, cornea refraction 100 ° - 43.8D and 10 ° - 39.9D, eye length 24.7 mm, cornea thickness in the center 540 microns, , ERG - the norm. Left eye: visual acuity without correction 1.0.

When ophthalmoscopy of the fundus of both eyes pathological changes were found. In the study of VEP in both eyes, a children's type of VEP was registered, having 3 peaks with the correct orientation, however, a decrease in latency (ti) was observed in the first (1) negative peak (having a normal amplitude of ZmkV) to 15 mena

right eye (Fig. 8). For the remaining parameters of the SGP, the difference between the right and left eyes was not revealed. The second peak (2) - positive has a latency (t2) of 80 ms and an amplitude of 22 μV, the third peak (3) - negative has a latency (ts) of 105 ms and an amplitude of 18 μV.

Conclusion: in both eyes, the children's type of VEP with the normal parameters of all components of the complex of the VIZ, except for reducing the latency of the first type on the right eye.

In order to correct the mixed astigmatism of a high degree, the patient underwent surgery - anteriorly dosed keratotomy on the right eye. Surgery and postoperative period without complications. Survey data 6 months after surgery. Right eye: visual acuity of 0.1 sph -0,, 3, corneal refraction 102 ° -42, ODi2 ° -41.8D, eye length 24.71 mm, cornea thickness in the center 540 microns,, ERG is the norm. Left eye: visual acuity without correction 1.0. When ophthalmoscopy of the fundus of both eyes pathological changes were found. As a result of the operation, the corneal astigmatism in the right eye was reduced from 3.9 to 0.2D. Despite the full refractive effect of the operation, the functional effect was significantly lower than in other cases, and the visual acuity with correction increased by only 0.2. To clarify the cause of the incomplete functional effect of the operation, the patient was prescribed a comprehensive examination. Computed tomography revealed a partial atrophy of the optic nerve on the right of a traumatic nature. Thus, it is correct to estimate the parameters of VEP, namely, focusing on reducing the latency of the first VEP peak on the right before the operation would allow the doctor to correctly guide the diagnosis and prescribe the necessary treatment (in this case, acupuncture).

PRI me R 9. Patient A., 9 years old, was admitted with complaints of low visual acuity with correction of both eyes. Clinical diagnosis: complex myopic astigmatism of a high degree, refractive amblyopia of a high degree in both eyes. Survey data. Right eye: visual acuity of 0.03 sph-6DC cyl-5, OD ah, 1, cornea refraction 99 ° - 44.5D and 9 ° - 39.5D, eye length 27.68 mm, cornea thickness in the center 505 microns,, ERG - myopic changes. Left eye: visual acuity 0.03 sph -5.5D cyl -5.0D ax, 1, corneal refraction 90 ° - 44.5D and 0 ° - 39.76D, eye length 27.4 mm,

corneal thickness at the center of 500 microns,, ERG - myopic changes. When ophthalmoscopy of both eyes: the optic nerve is pale pink with clear

boundaries, myopic cone 2 / HFA, macular region and blood vessels are normal, redistribution of pigment in the periphery,

In the study of the SGP in both eyes, an adult type of SG was registered,

0 whose complex had 4 peaks, the first peak (1) was negative with a latency (ti) of 80 ms and an amplitude of 12 μV, a second peak (2) positive with a latency (t2) of 150 ms and an amplitude of 26 μV, the third peak ( 3) - negative with latency (ta) 180 ms and amplitude 14 μV, fourth peak (4) - positive with latency (t4) 215 ms and amplitude 7 μV (Fig. 9)

Conclusion: adult in both eyes

0 type of SGP with the normal number of peaks and the normal characteristics of these peaks, except for increasing the latency of the second peak to 150 ms.

In order to correct a complex myopic astigmatism of a high degree, the patient underwent anteriorly dosed tangential keratotomy in both eyes. Surgery and postoperative period without complications. Survey data

0 after 6 months after surgery. Right gaz: visual acuity 0.1 sph-7,, 2, corneal refraction 98 ° - 42.5D and 8 ° - 40.5D, eye length 27.65 mm, cornea thickness at the center 500 microns,, ERG - identical to the previous operating room . Left eye: visual acuity 0.1 sph -7.5D 0.2, corneal refraction 92 ° - 42.25D and 2 ° - 41.25D, eye length 27.36 mm, cornea thickness in the center 500 microns, ERG - identical preoperative. With eye fundus ophthalmoscopy, no new changes were noted. As a result of the operation, corneal astigmatism in the right eye was reduced from 5.0 to 2, OD, and in the left eye, from 4.75 to 2, OD. Noting a significant refractive effect of the operation, the functional effect was significantly lower than in other cases: visual acuity with correction increased by only 0.1. To clarify the cause of the low functional effect of the operation, the patient was prescribed an additional examination and using computed tomography revealed changes in the optic nerves of an inflammatory nature with partial atrophy (presumably as a complication of viral infection).

Thus, the assessment of all components of the VEP before the operation is correct, and in this case the increase in the latent period of the first peak of the VIZ. would allow correctly

make a diagnosis and not carry out inappropriate operation.

An example. Patient P., 7 years. she complained of low visual acuity with correction. The girl had difficulty mastering the school program.

Clinical diagnosis: complex myopic astigmatism of a high degree, refractive amblyopia of a high degree. Survey data. Right eye: visual acuity 0.05 sph -2.5 cyl -5, OD ah, 1, cornea refraction 100 ° - 47.25D and 10 ° - 42.25D, eye length 24.38 mm, cornea thickness in the center 540 microns, , ERG-norm. Left eye: visual acuity 0.05 sph-2.5 D cyl -4.5 D ax, 1, corneal refraction 90 ° - 47, OD and 0 ° - 42.5 D, eye length 24.32 mm, cornea thickness in the center 540 microns,, ERG - the norm. Ophthalmoscopy of the eye fundus of both eyes: a pale pink optic nerve disc with clear boundaries, a narrow myopic cone, a macular area without pathological changes, a caliber of vessels as normal, no focal changes.

In the study of the SGP in both eyes, a children's type of SGP was registered, in the complex of which 3 peaks were identified. The first peak (1) is negative with a latency (ti) of 60 ms and an amplitude of 2 µV, the second peak (2) is positive with a latency (ta) of 195 ms and an amplitude of 22 µV, the third peak (3) is negative with a latency (( ts) - 265 ms and an amplitude of 22 μV (Fig. 10).

Conclusion: in both eyes, the children's type of VEP with a normal number of peaks. An increase in the latency of the second and third peaks is noted.

The patient underwent anteriorly dosed tangential keratotomy to correct a high degree of complex myopic astigmatism. Surgery and postoperative period without complications. Survey data 4 months after surgery. Right eye: visual acuity of 0.2 with sph -3,, 2, corneal refraction 100 ° - 44.5D and 10 ° - 43.25D, eye length 24.39 mm, cornea thickness in the center 540 microns,, ERG is the norm. Left eye: visual acuity of 0.1 sph -3,, 3, corneal refraction 90 ° - 44.5D and 0 ° - 43.5D, eye length 24.36 mm, cornea thickness in the center 540 microns,, ERG - normal. When ophthalmoscopy new changes in the fundus of both eyes is not marked.

As a result of the operation, corneal astigmatism in the right eye was reduced from 5.0 to 1.25 D and in the left eye from 4.5 to 1, OD. However, despite such a high refractive effect of the operation, the functional effect on both eyes was low, since the visual acuity of the correction increased only on the right eye by 0.1, and on the left by 0.2. To reveal the cause of the naked functional effect of the operation, the patient was scheduled for additional examination. With the help of computed tomography, congenital hypoplasia of the optic nerves and other

structures of the conductive paths of the visual analyzer. Thus, a correct assessment of the increase in the latency of the second and third peaks of the VEP complex would allow the attending physician to be oriented correctly and not to carry out an inexpedient operation to the child.

Contraindications to the examination of VEP are neurological conditions with a predisposition to seizures (epilepsy, etc.).

The proposed method of determining contraindications for carrying out operations for refractive errors in children can be used in all cases for

deciding whether it is advisable or inappropriate to carry out operations for refractive errors in children. Using the proposed method allows to accurately determine the contraindications to

the operation - keratotomy.

Clinical testing has shown that empirically derived criteria for evaluating contraindications for surgery are confirmed in 85%

cases.

In addition, this method allows, with low visual acuity, without corresponding changes in the fundus of the eye fundus, to differentiate refractive amblyopia with other diseases. The technique allows, without additional and not always feasible, complex neurological and special expensive instrumental examination methods (contrast angiography, computed tomography, etc.) to correctly orient the doctor in the diagnosis and selection of the appropriate method of treatment of the established pathology.

Claims (1)

Invention Formula The method for determining contraindications to surgery for refractive anomalies in children by measuring evoked potentials, characterized in that, in order to increase accuracy, the number of peaks of evoked potential, their latency and polarity are measured and /or reducing the number of peaks and / or changing the latency of one or more peaks compared to the norm consider the operation to be impractical. 1 FIG. 2 Fi.Z PhieA 5 FIG. 6 FIG. 7 Fie.9 FIG. ten