Calculation of tunnel incision parameters during phacoemulsification in patients with previous anterior radial keratotomy

Background. The purpose was the choice of the type of tunnel incision on the basis of mathematical calculations in cataract patients with a previous anterior radial keratotomy. Materials and methods. During the calculations, the formula for the chord length of a circle was used: L = 2R · sin(α/2), where R is the radius of the cornea, α is the angle (in degrees) between the two corneal incisions. The chord length was measured on the limbus (upper edge of the tunnel incision) and 2 mm from the limbus (lower edge of the tunnel incision). The chord 2 mm from the limbus is more important because the distance between kerato­tomy incisions at this site is smaller. From 0.4 to 1.0 mm must be added to the width of the knife blade, depending on the type of postoperative corneal healing, which will be the key to crossing the incisions. Results. The most common knives are those 2.2 mm long with a tunnel length of 2 mm. Therefore, we perform calculations based on this knife in patients with 8 and 12 keratotomy incisions and a corneal diameter of 12 mm vertically and 11 mm horizontally. In patients with 8 keratotomy incisions, a 2.2 mm knife can be used for a corneal tunnel incision, and in patients with 16 incisions, it is impossible to use a corneal tunnel. Conclusions. In cataract patients who have previously undergone anterior radial keratotomy, a special approach is needed to the choice of tunnel incision. The choice of access depends on the diameter of the cornea, the number of keratotomy incisions and the width of the knife and is calculated using the formula for the chord length of a circle.

Modern view on the etiopathogenesis of age-related macular degeneration and the role of molecular genetic determinants in it

Age-related macular degeneration mainly affects the elderly and is one of the most common causes of rapidly progressive vision loss. Over more than 150 years of research, the scientific community has gone from understanding the macroscopic picture of the lesion, presumable identification of drusen as the main morphological manifestation of nosology, to detailed classifications and determine the role of genetic determinants in the etiopathogenesis of the disease — high specificity, the possibility of preventive analysis, and much unclear in the field of genetic diagnosis of eye diseases determine the accurate attention of specialized research groups to the early diagnosis using genetic analysis. The review article was aimed to systematize the information about possible links in the pathogenesis of age-related macular degeneration and identify potential polymorphisms that can initiate and modulate the activity of these links. During the study, we could find out five main mechanisms of damage to the vascular membrane of the eye itself, which are affected by single nucleotide polymorphisms. The hig­hest affinity was shown by genetic variants of separate sites of CFH (rs1061170), HTRA1 (rs11200638), TNF (rs1800629), VEGFA (rs2010963). Literature data obtained from foreign and national sources indexed by Scopus, Web of Science databases, in particular for the last 5 years, pay special attention to these areas as potential predictors or modifiers of pathological processes involved in the process of macular degeneration. Despite the large number of studies examining the predisposition, pathogenesis, diagnosis, and treatment of age-related macular degeneration to stop the spread of vision loss, only a few issues are understood thoroughly. Considering the successful cases of application of biological and gene therapy for the management of such patients, we see new horizons in the detailed study of molecular interactions that underlie the pathology. The review confirms the active role of polymorphisms in one of the most relevant pathological processes of the human eye.

Historical aspects of ophthalmoplasty (Odesa school)

The work presents the main milestones of the Odesa ophthalmoplastic school. The historical perspective shows the formation and development of ophthalmoplasty from the XIX century to the present day, preserving and emphasizing the continuity of its existence. Information on some prominent scientists dealing with the problems of the orbit and periorbital area in Odesa is given. Particular attention is paid to scientific developments in reconstructive surgery of the patho­logy of the auxiliary eye apparatus and orbit in pediatric patients. The knowledge and use of the accumulated experience will allow modern ophthalmoplastic surgeons to widely implement and improve the best methods and techniques of reconstructive and restorative operations on the auxiliary eye apparatus and periorbital area.

Dry eye disease in students with myopia during COVID-19 pandemic

Background. Today, the urgent problem is coronavirus disease 2019 pandemic in the whole world. Safety measures such as the use of masks, distance learning have been implemented. However, ophthalmologists, as well as the general population, should know that a face mask together with prolonged use of digital devices leads to an increase in the number of dry eye cases in many patients. The purpose was to study the frequency of dry eye disease in students with myopia. Materials and methods. The study involved 96 medical students diagnosed with myopia taken by random sampling, who were examined by an ophthalmologist. Apart from the standard ophthalmologic examination, all patients underwent the evaluation of the stability of the precorneal tear film by means of corneal topography, and Norn test (tear break-up time (TBUT)). There was also used a standard questionnaire designed to assess the severity of dry eye disease symptoms (Ocular Surface Disease Index). Results. The corneal topography of the 47 patients did not demonstrate any reduction in TBUT. The average time of the concentric ring remained stable for 20.2 ± 3.0 seconds. But 49 individuals exhibited signs of tear film instability over time compared to 47 patients without TBUT impairment. In 47 people without impairments, corneal topography demonstrated that this indicator in Norn test varied from 25 to 18 seconds, i.e. was within the age norm (21.5 ± 3.5 seconds on average). In 3 patients with a minimum TBUT on keratotopography, its value during the Norn test was 9 seconds. In 36 patients with reduced TBUT according to both methods, there was a weak degree of dry eyes, in 10 — moderate, in 3 — severe. The most common complaints were a sandy, gritty sensation in the eyes, visual discomfort when working at a computer and in windy weather, and with prolonged use of a protective mask. Conclusions. Among students who were on distance learning, 51.04 % of individuals have objectively confirmed dry eye disease. People wearing contact lenses have a more pronounced degree of dry eye, so it is mandatory for ophthalmologists to prescribe lubricating eye drops.

Hemophthalmia after surgical treatment of diabetic retinopathy in patients with type 2 diabetes mellitus

Background. In patients with type 2 diabetes mellitus (DM2) and diabetic retinopathy (DR), vitreous hemorrhage is one of the most common complications after pars plana vitrectomy (PPV) and ranges from 12 to 63 %. The study was aimed to analyze the frequency and causes of the development of hemophthalmia after surgical treatment of diabetic retinopathy in patients with type 2 diabetes mellitus. Materials and methods. The study involved 118 patients (118 eyes) with type 2 diabetes mellitus and DR, who were divided into three groups: the first group — with initial non-proliferative DR (NPDR; 28 eyes), the second group — with moderate to severe NPDR (49 eyes) and the third group — with proliferative DR (РDR; 41 eyes). The age of patients ranged from 44 to 84 years, men — 52 (44.1 %), women — 66 (55.9 %). The study did not include the patients with severe PDR and tractional retinal detachment or massive hemorrhage that required silicone oil tamponade of the vitreal cavity. All patients underwent closed subtotal vitrectomy 25G with panretinal laser photocoagulation and tamponade with an air-gas C3F8 mixture or the operation was completed with BSS plus solution injected into the vitreal cavity. Patients were examined based on a standard protocol of clinical and ophthalmological studies. Results. Within three months after vitrectomy, 33.1 % of patients developed postoperative hemophthalmia, which happened more often in РDR (39.0 %). In most cases (71.4 %), the preoperative hemophthalmia in РDR was accompanied by the development of postoperative hemophthalmia. Gender did not significantly impact the incidence of postoperative hemophthalmia. Patients with hemophthalmia were 9.3 years older than patients without hemophthalmia (p < 0.001), which affected both men and women equally. Patients with hemophthalmia had a longer history of type 2 diabetes mellitus compared to those wi­thout it (three years; p = 0.007), which was confirmed for men: men with hemophthalmia had a longer history of type 2diabetes mellitus than those without hemophthalmia (seven years; p = 0.026). Elevated blood levels of glycated hemoglobin (HbA1c) and a high score on the ETDRS scale are the risk factors for the development of postoperative hemophthalmos in patients with РDR. Conclusions. A study within three months after PPV in patients with DR and type 2 diabetes mellitus found that 33.1 % of patients developed postoperative hemophthalmia, which occurred more often in РDR (39.0 %). In most cases (71.4 %), the preoperative hemophthalmos in РDR was accompanied by the development of postoperative hemophthalmia. The risk factors for postoperative hemophthalmia after vitrectomy in type 2 diabetes mellitus and DR were age and diabetes duration, and for РDR — the presence of preoperative hemophthalmia, increased blood glycated hemoglobin, and a high score on the ETDRS scale.

New genetically determined risk factors of diabetic retinopathy in type 2 diabetes mellitus: final report

Background. According to the International Diabetes Federation, the number of people with diabetes mellitus is going to increase from 366 to 552 million by 2030. More than 1.5 million patients with diabetes are registered in Ukraine, of which 84–95 % have type 2 diabetes. Diabetic retinopathy (DR) is one of the common diabetes complications, being one of the leading causes of blindness and low vision, in particular in people of occupational age. Metabolic disorders, including activation of the polyol pathway of glucose utilization, play an important role in the pathogenesis of DR, with aldose reductase playing a key role, the activity of which is associated with the polymorphism of its gene, AKR1B1. The study of new meta­bolic and genetic mechanisms for the development and progression of DR in type 2 diabetes mellitus in patients from the Ukrainian population is an actual task of modern ophthalmology. Purpose: to investigate and generalize new genetically determined risk factors for diabetic retinopathy in type 2 diabetes mellitus. Materials and methods. The study involved 409 participants, who were divided into four groups: 1 — comparison cohort (98 people without diabetes mellitus type 2); 2 — 76 patients (stage I DR, without fundus chan­ges); 3 — 64 individuals with non-proliferative DR; 4 — 64 patients with proliferative DR; control group for genetic researches included 107 ophthalmologically healthy individuals. All patients underwent blood sampling for molecular genetic research by puncture of the ulnar vein and aspiration of 2.5 ml of blood through a 23G 5.0 ml disposable syringe (Hemoplast, Etalon+, Ukraine), followed by a release into a 3.0 ml container (Vacuette K3E K3EDTA, Greiner Bio-One, Austria). Distribution of polymorphic alleles and genotypes of rs759853 and rs9640883 aldose reductase gene (AKR1B1) in patients with non-proliferative DR, proliferative DR and in the control group and their association with disease and effects on the occurrence, mechanisms of development and progression of DR were studied. Based on the conducted researches, a model of DR development prognosis was developed by construction of multiple regression with sufficient reliability of degree of influence of independent variables on a calculated indicator. Results. As a result of our research, we identified new genetically determined risk factors for the development and progression of the different stages of DR in patients with diabetes mellitus type 2, namely the role of polymorphic alleles and genotypes rs759853 and rs9640883 of the AKR1B1 gene. The deve­loped logistic regression models found that the risk of DR incidence is five times lower in carriers of the G/G and G/A genotypes compared to carriers of the A/A genotype rs759853 polymorphism (p < 0.001). It was found that the risk is twice as high (p = 0.01) for carriers of the G/G genotype rs9640883 compared to the A/A + G/A genotypes. The risk of developing proliferative DR is 3.3 times lower in carriers of the G/G genotype and 2.5 times lower in carriers of the G/A genotype compared to carriers of the A/A genotype rs759853. Conclusions. Therefore, on the basis of our clinical, ophthalmological, molecular genetic and statistical studies we have identified new risk factors for the development and progression of different stages of DR in patients with diabetes mellitus type 2. Mathematical models of development and progression of different stages of DR in patients with diabetes type 2 were built.

The effectiveness of hyperopia correction by wearing contact lenses in school-age children in the long-term follow-up

Background. Glasses and correction by wearing contact lenses are well tolerated by children with mild to moderate ametropia. In ametropia of high degree, an improvement of mo­nocular visual acuity with a contact lens compared to correction by glasses is 3.8 times higher. Materials and methods. The study included 56 children (112 eyes) aged 6 to 16 years with hypero­pic refraction and astigmatism, who used soft silicone hydrogel contact lenses to correct ametropia. In these patients, visual acui­ty, objective and subjective clinical refraction, axial length of the eye, corneal thickness and diameter, keratometry indicators were investigated, as well as phorometric data (accommodation, vergence, disparity areas of the oculomotor system and their inte­raction) in the early and late observation periods. Results. When using contact lenses for correction in school-age children with hyperopia and hyperopic astigmatism, after 3 years of observation there was a statistically significant increase in uncorrected visual acuity by 85 % (t = 7.9; p < 0.01), corrected visual acuity by 7 % (t = 7.4; p < 0.01), keratometry indicator in the weakest meridian by 1 % (t = 6.1; p < 0.01), in the strongest meridian by 1 % (t = 8.9; p < 0.01), central corneal thickness by 4 % (t = 4.6; p < 0.01), as well as a decrease in the spherical equivalent by 38 % (t = 3.1; p < 0.01), the amplitude of accommodation by 20 % (t = 5.8; p < 0.01), the negative relative accommodation by 20 % (t = 3.0; p < 0.01), the positive relative accommodation by 18 % (t = 3.5; p < 0.01), excessive accommodative response by 64 % (t = 7.2; p < 0.01), near phoria by 33 % (t = 4.4; p < 0.01), distance phoria by 22 % (t = 2.8; p < 0.01), the accommodation convergence to accommodation ratio by 18 % (t = 3.1; p < 0.01).

Forms to improve the quality of postgraduate training of ophthalmologists

The main direction of improving the process of professional development of doctors at the stage of postgraduate training is the gradual introduction of modern forms of education. Internship is the first step to independent work of a doctor, so it is important from this stage to direct the efforts of a young specialist to self-improvement. Traditional methods of training interns are primarily aimed at obtaining and deepening knowledge through the transfer of information with subsequent implementation in specific professional activities with recognized algorithms. However, this method of teaching does not contribute to the development of independent cognitive activity of young colleagues, although it is on this postulate the concept of distance learning is based as a new form of postgraduate education. The article characterizes the modern system of training of interns-ophthalmologists. The use of distance learning, clinical analysis of patients’ data, stage test control, situational tasks in the educational process is substantiated. Wishes are expressed to improve the organization of the internship in ophthalmology.

Again about carbonic anhydrase inhibitors: modern aspects of the use of ICA in ophthalmology

For more than 70 years, the inhibitors of carbonic anhydrase (ICA) have been used in the treatment of glaucoma. Since 1995, topical forms of ICA have appeared among antiglaucoma drugs — dorzolamide, and since 1999 — brinzolamide. The hypotensive efficacy and safety of topical ICA gave rise to the widespread use of these drugs in the treatment of various forms of glaucoma. The peculiarities of the mechanism of action made it possible to create on their basis effective fixed combinations, which allow reducing the intraocular pressure by up to 40 % in patients with glaucoma. The attractiveness of the drug has expanded due to the effect of ICA on various tissues of the organ of vision. Thus, ICAs effectively improve the hemodynamics of the eye and optic nerve. The antioxidant activity of the drug makes it possible to expand the indications for its use in patients with vascular patho-logy of the retina and optic nerve. The biomechanical characte-ristics of the drug allowed its effective and safe use in the complex treatment of macular edema of various etiologies. The adjuvant use of topical ICAs expands the possibilities of anti-VEGF therapy in the treatment of macular edema of various etiologies. Features of the action of ICA on the endothelial pump function of the cornea made it possible to formulate the rules for the use of topical ICA in patients with an insufficient function of the corneal endothelium.

Usage of 0.4% sodium hyaluronate in complex treatment of pediatric patients with dry eye syndrome against the background of allergic diseases of the organ of vision

Background. In recent years, the prevalence of allergic diseases of the anterior chamber of the eye has increased. They are often accompanied by the development of dry eye syndrome, which can complicate their course. Therefore, it is important to take a comprehensive approach to their diagnosis and treatment. The purpose was to study the effectiveness of 0.4% sodium hyaluronate (Gilays) in children with dry eye syndrome on the background of allergic diseases of the conjunctiva. Materials and methods. The study involved 42 patients (84 eyes) aged 3 to 18 years, who were examined and treated on the basis of Regional Eye Clinic. Patients were treated with local H-1 histamine blockers twice a day for 14 days, f necessary — with topical glucocorticoids by the scheme for 12 days. In the first group (21 patients, 42 eyes), the main treatment was added with the drugs containing 0.2% sodium hyaluronate, used topically 4 times a day for 14 days. In the second group (21 patients/42 eyes), 0.4% sodium hyaluronate (Gilays) was added to the treatment regimen. H-1 histamine blockers were not used systemically. Before starting therapy and 2 weeks later, the following values were evaluated: the changes in the anterior chamber of the eye using biomicroscopy, determination of lacrimal film rupture time, Schirmer 1 test, questionnaire. Conclusions. The use of sodium hyaluronate in the complex therapy of dry eye syndrome in allergic eye diseases is quite effective. The use of 0.4% sodium hyaluronate was more effective compared to the control group. It is advisable to use a questionnaire to communicate with the child, but it is necessary to refine the form of questions to eliminate as much as possible the subjectivity of the data.