[Biomechanical properties of the anterior lens capsule after manual and femtolaser capsulotomy]

[Modern approaches to the treatment of anterior capsule contraction syndrome]

Anterior capsule contraction syndrome is a specific complication of continuous circular capsulorhexis in various phacoemulsification techniques. Surgical, laser and combined methods have been proposed for its treatment. All approaches in the treatment of anterior capsule contraction syndrome have some advantages, as well as certain problems and difficulties. This review presents the current state of this problem of cataract surgery and possible prospects for improving the treatment.

[Phaco surgery in disorders of the capsular-zonular apparatus of the lens]

The article presents authors' original methods of phaco surgery that can be used in disorders of the capsular-zonular apparatus of the lens. The cataract surgery techniques for lens subluxation developed and introduced into clinical practice allow using the most physiologically correct intracapsular intraocular lens (IOL) fixation in the vast majority of cases. The introduction of femtosecond laser at key stages of phacoemulsification in complicated clinical situations reduces the dependence of the results on the human factor and allows performing removal of complicated cataracts at a qualitatively new level.

[Hybrid (femtolaser) phacoemulsification: technical aspects and functional results]

This article summarizes scientific and practical results of hybrid femtosecond laser-assisted phacoemulsification (HFE) including study of clinical and technical aspects of the intervention and evaluation of post-surgical functional state of the eye on the basis of clinical, morphological and biomechanical data. The HFE technology should be considered the method of choice for microinvasive phaco surgery, its main advantage being the possibility of controlled handling of such important surgical stages as anterior circular continuous capsulorhexis and nucleus fragmentation on a closed eyeball, which significantly reduces the risk of complications and decreases of effective ultrasound time.

[Methods of studying deformation properties of ocular structures]

Studying ocular biomechanics presents apparent interest because of certain clinical situations when in vivo 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.

[Experimental studies of the biomechanical properties of the cornea]

The review presents the results of experimental studies of the biomechanical properties of the cornea. Selective evaluation of the individual corneal structures (for example, limiting membranes) using classical mechanical tests is to a certain extent limited due to the rather small thickness of these structures and the related difficulties in sample fixation. In real practice, the use of a method better adapted for conducting such studies - atomic force microscopy (AFM) - remains promising, since on the one hand it eliminates the need for mechanical capture and retention of the sample, and on the other - provides the capability for studying its segments separately.

[Surgical treatment of hypermature cataract in patients with lens subluxation and small pupil]

Studying the possibilities of hybrid (femtosecond laser-assisted) phacoemulsification in complicated situations is a relevant problem in cataract surgery.

PURPOSE

To develop a technique for hybrid (femtosecond laser-assisted) phacoemulsification in patients with a combination of hypermature cataract, small pupil and lens subluxation.

MATERIAL AND METHODS

Hybrid (femtosecond laser-assisted) phacoemulsification of hypermature cataracts was performed in 36 patients (36 eyes) aged 63 to 78 years with grade I-II lens subluxation in combination with small pupil. The initial circular femtolaser capsulotomy was performed within the small pupil using the VICTUS system (Technolas Perfect Vision, Germany). After dilating the pupil with retractor hooks, the capsulorhexis was manually expanded to the required diameter.

RESULTS

In all cases, the resulting capsulorhexis had a regular round shape with a smooth edge, without radial ruptures. This made it possible to apply modern methods of fixation and centration of the capsular bag in case of lens subluxation and to perform intracapsular implantation of an intraocular lens (IOL). Complete intracapsular fixation of the IOL with optics edge fully covered by the edge of the capsulorhexis in the postoperative period was achieved in 34 (94.4%) cases. In 2 (5.6%) cases in the postoperative period, the edge of the capsulorhexis exceeded the edge of the IOL optics. The loss of corneal endothelial cells 3 months after surgery was 8.8±1.9%.

CONCLUSION

The use of the proposed combined technique of capsulorhexis made it possible to perform the most physiologically appropriate intracapsular IOL implantation in all patients with hypermature cataract, small pupil and lens subluxation.

[Femtosecond laser-assisted phacoemulsification of hypermature cataract in patients with lens subluxation]

Studying the modern capabilities of femtosecond laser in the treatment of complicated cataracts is a topical problem in cataract surgery.

PURPOSE

To develop a technique for femtosecond laser-assisted phacoemulsification of hypermature cataract in patients with degree I-II lens subluxation.

MATERIAL AND METHODS

Phacoemulsification of hypermature cataract with comorbid lens subluxation was performed in 78 patients (78 eyes) divided into two groups. In the 1st group (45 eyes), capsulorhexis was performed using a femtosecond laser. Patients of the 2nd group (33 eyes) underwent manual capsulorhexis. The study assessed the possible frequency of using modern methods of capsular bag fixation and complete all-in-the-bag intraocular lens (IOL) implantation, as well as the number of various types of intraoperative capsular bag ruptures.

RESULTS

In all patients of the 1st group, capsulorhexis of the correct round shape and the required diameter was achieved, allowing the use of modern methods of fixation and centering of the capsular bag. Insignificant tear of the edge of the capsulorhexis after IOL implantation was detected only in 1 (2.2%) patient. Vitreous prolapse was noted in 1 (2.2%) case. In the 2nd group, manual technique resulted in oval capsulorhexis with a smooth edge, allowing the use of modern methods of fixation of the capsular bag only in 7 (21.2%) cases. Vitreous prolapse was noted in 4 (12.1%) cases. The complete in-the-bag IOL implantation was possible in 44 (97.8%) cases in the 1st group and only in 7 (21.2%) in the 2nd group.

CONCLUSION

The use of femtosecond laser in patients with hypermature cataract and lens subluxation allows achieving capsulorhexis of ideally round shape with a smooth edge. This creates the necessary conditions for the use of modern methods of fixation of the capsular bag and provides the possibility of complete all-in-the-bag IOL implantation.