[Application of parametric statistics to visual acuity data].

Unlabelled: ETDRS charts with logarithmic notation are widely used for measuring visual acuity in clinical studies worldwide. However, the distribution of measurement results often deviates from normal, limiting the applicability of parametric statistical methods, which are more powerful than the non-parametric ones. In cases of significant skewness, raw data can undergo power transformation with varying exponents (λ), as described by J.

[The effect of keratoconus-associated refractive errors on the results of tomographic methods of studying the posterior structures of the eye].

Purpose: The study assesses the potential influence of refractive errors in keratoconus (KC) on the results of tomographic methods of studying the structures of the posterior eye segment.

Material And Methods: The study included 30 patients with bilateral stabilized KC of stages I-IV in classification by M. Amsler.

[Comparison of visometry by Sivtsev and ETDRS charts].

Unlabelled: Most foreign authors currently recommend the protocol and charts developed for the Early Treatment Diabetic Retinopathy Study (ETDRS) as the gold standard for evaluation of visual acuity (VA) in clinical trials and studies. Not every medical facility has equipment required for performing visometry by that method, while Sivtsev tables are found universally.

Objective: To compare ETDRS and the more common Sivtsev visometry methods.

[Methods of studying deformation properties of ocular structures].

Studying ocular biomechanics presents apparent interest because of certain clinical situations when evaluation of mechanical properties can help with both diagnosis and treatment. This literature review considers the approaches to studying deformation properties of various ocular structures: dynamometric methods, elastotonometry, ophthalmic mechanography, photoelasticity method, ultrasound methods, analysis of pneumatic applanation of the cornea, atomic force microscopy, holographic interferometry, optical coherence elastography. Knowledge of the particularities of tissue deformation during examination with various methods can expand our understanding of the mechanisms of pathological changes in different structures of the organ of vision, which can help develop new methods of diagnosis and treatment.

[Results of confocal microscopy of the cornea after bandage therapeutic-optical keratoplasty in keratoconus].

Unlabelled: Bandage therapeutic-optical keratoplasty (BTOK) is one of the modern methods of surgical treatment of keratoconus (KC) that allows to improve visual functions by changing keratotopographic and pachymetric parameters of the cornea in the zone of ectasia. Long-term results show that changes also affect the central part of the cornea, which tends to flatten.

Purpose: To compare the light confocal microscopy appearance of the cornea before and after BTOK surgery.