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Biomedical subjects

S Synek

Publications and source records attributed to S Synek.

At least 19 recordsLinked to original sources
PubMed2005

[Effect of viscoelastic substances on postoperative intraocular pressure in phacoemulsification].

The Influence of the Type of Viscoelastic Substances on the Level of Intraocular Pressure after Phacoemulsification The aim of study was to asses the influence of the type of viscoelastic substances on the level of intraocular pressure (IOP) after cataract surgery and intraocular lens (IOL) implantation. In the study group of 100 patients Viscoat was used at 32 operated eyes, Provisc at 14 eyes and Duovisc in 54 eyes during phacoemulsification and IOL implantation. IOP was measured before surgery, one day after surgery and one week after surgery. Mean IOP level 1. day postoperatively was 24.94 mmHg in the Viscoat group of eyes, 24.65 mmHg in the Provisc group and 21.09 mmHg in the Duovisc group. The type of viscoelastic substance used during the surgery significantly influenced the level of IOP in the first postoperative day. The level of IOP was significantly lower in the Duovisc group comparing to Viscoat and Provisc. The level of IOP did not differ significantly between the Viscoat and Provisc group. One week after surgery the level of IOP was not significantly different between all types of viscoelastic device. Duovisc was the most profitable viscoleastic substance in the point of view of the course of phacoemulsification, IOL implantation and postoperative level of IOP.

Aged↗
PubMed2005

[The cases of penetrating eye injuries with large intraocular foreign body].

AIM: Three consecutive cases of penetrating eye injuries complicated with large (size 9-12 mm) intraocular foreign body are presented as such. PATIENTS AND METHODS: The initial findings, management, surgical procedures and final anatomical and functional outcomes of each particular case are given. Corneal entrance laceration was seen in all three patients. Second scleral full-thickness eye wall laceration was found just posterior to the horizontal muscle insertions in two eyes. Full-thickness exit posterior eye wall laceration obturated with foreign body was diagnosed in one case. This metallic foreign body projected into posterior orbit. Two eyes were injured with metallic radio opaque foreign body. Glass fragment was removed from posterior segment of the eye in one patient. Following primary wound closure pars plana vitrectomy was performed to remove all posterior segment intraocular foreign bodies. RESULTS: Silicone oil was used to fill the vitreous cavity at the end of the surgery in two eyes. Gas bubble (perfluoropropane, C3F8) was injected into the vitreous space at the end of the vitrectomy in one eye. The authors observed following complications: vitreous cavity haemorrhage, traumatic cataract formation, cystoid macular oedema and peripheral stationary traction retinal detachment. CONCLUSION: Good anatomical results and restoration of good visual functions of injured eye were achieved in all patients despite some inferior initial prognostic factors.

Adult↗
PubMed2005

[Ultrastructure of the iris pigmentary epithelium].

The iris pigmentary epithelium has identical structure as the retinal epithelium has. The peripheral iridectomy makes it possible to obtain sufficient amount of tissue to be used for the multiplication of the pigmentary epithelium cells in tissue culture, or, for direct implantation into the subretinal space. The technique of the peripheral iridectomy is regardful enough; in none of the specimens mechanically damaged cells were found.

Aged↗
PubMed2005

[Bilateral Terrien's degeneration treated by corneoscleral graft transplantation].

Authors operated on a patient with bilateral corneal involvement in Terrien's marginal degeneration and spontaneous corneal perforation. The surgery was performed in both eyes at the same time and a free sclerocorneal graft was used. The postoperative cosmetical and functional results as well were very good. It is advisable to follow up the patients with Terrien's marginal dystrophy. The surgery on right time removes the defect of the cornea and accompanying high corneal astigmatism.

Corneal Diseases↗
PubMed2005

[Transmission electronic microscopy of the inner limiting membrane and epiretinal tissue in idiopathic macular hole].

The authors examined samples of epimacular tissue obtained during the surgeries of the idiopathic macular hole in different stages of the disease by means of transmission electronic microscopy. In the early stages of the disease only the inner limiting membrane with isolated cells on the vitreous side was present, in later ones of the disease the connective tissue membrane was attached. In rare cases of the later stages of the disease they found the presence of the retinal pigment epithelium (RPE). They suppose the RPE plays an important role in the regeneration of the defects of the retina.

Aged↗
PubMed2004

[Comparison of ultrasound and optic biometry with respect to ocular refraction after cataract surgery].

In the prospective study of 56 patients with cataract (67 eyes) the authors compared axial length biometry) regarding to postoperative refraction of the eyes. Dioptric power of the intraocular lens (IOL) was determined by SRK II. formula. The difference between predicted and actual postoperative refraction in the spherical equivalent were compared 3 months postoperatively. Axial length measured by ultrasound differed significantly from the axial length measured by optical biometry (p = 0.016). Dioptric power of IOL calculated according to the axial length measured by ultrasound was significantly different from the dioptric power of IOL calculated according to the axial length measured by optical biometry (p = 0.003). The difference between predicted and actual postoperative refraction was not statistically significant (p = 0.384) even if we considered both type of measurement. In conclusion, we found partial coherence interferometry was an accurate and reproducible method for measurement of axial length of the eye before cataract surgery. In the cases of advanced dense cataracts backup of ultrasonic biometry is still necessary.

Cataract↗
PubMed2004

[Structural analysis of the optic nerve head in healthy eyes and in eyes with glaucoma].

PURPOSE: Assess the possibilities of structural analysis of the optic nerve head by Heidelberg Retina Tomograph (HRT) and its use in detection of glaucomatous changes of the optic nerve in particular. Indicate the topographical parameters that are most influenced by glaucoma and are therefore vital in early diagnosis of glaucomatous changes of the optic nerve. PATIENTS AND METHODS: Laser scanning tomography (HRT II) was used to examine 68 healthy eyes (control group) and 42 eyes with open angle glaucoma (study group). All the examined subjects were older than 35 years of age. The analysis concerned the following topographical parameters of the optic nerve head: disc area, cup area and rim area, cup volume, rim volume, cup/disc area ratio, mean cup depth, maximum cup depth, mean retinal nerve fiber layer thickness (RNFL), RNFL cross sectional area, height variation contour and cup shape measure and discriminant functions used for classification of the optic nerve head finding according to F. S. Mikelberg and R. Burk. Statistical analysis was employed to ascertain the significant difference in these topographical parameters for the healthy eyes and the eyes with glaucoma. This method was used for both the whole optic disc and the 6 sectors of the optic nerve head. Another aim of the analysis was also to find out the correlation between the topographical parameters and age. RESULTS: Significant difference in the topographical parameters for the whole optic disc was spotted in the following parameters: rim volume, mean RNFL thickness, RNFL cross sectional area and discriminant function FSM. Significant differences were also found in between individual sectors of the optic nerve head, except for the upper temporal and upper nasal sector. The parameter, which varied most frequently between the groups, was rim volume. Significant correlations between age and topographical parameters were found for the following parameters: rim area, cup shape measure and mean RNFL thickness. CONCLUSION: Results of our study showed, that HRT is able to distinguish between normal and the pathological findings of optic nerve head according to topographical parameters significantly different between the two examined groups. These parameters are important in the diagnosis of glaucoma and also in the follow-up of patients with open angle glaucoma.

Adult↗
PubMed2002

[Intraocular pressure in phacoemulsification].

The authors investigated changes of the intraocular pressure after non-complicated phacoemulsification with implantation of an intraocular lens of different types (OMMA, silicone, Acrysof) in 40 patients. From the results it is obvious that in some patients already 4 hours after surgery the intraocular pressure rises to an average of 31 +/- 17 mm Hg. The magnitude of the intraocular pressure was not influenced by the size of the surgical wound nor the type of intraocular lens. In values below 30 mm Hg the authors recommend merely follow up of the patients as they assume that these values have a positive impact on closure of the tunnel incision. In the differential diagnosis it is important to consider the post-operative inflammatory reaction, the absorption reaction of residual viscoelastic material, pupillary block while the lenticular capsule is intact and undiagnosed glaucoma. In values above 30 mm Hg the authors recommend administration of beta-blockers, Diluran and antiphlogistics.

Humans↗
PubMed2002

[Pseudophakic retinal detachment in relation to complications of cataract surgery].

The authors made a retrospective study in a group of 14 patients operated in 1999 on account of pseudophakic detachment of the retina (D.R.). They followed up risk factors of development of D.R. in conjunction with complications of cataract surgery. The investigated factors comprised patients sex and age, type of cataract operation and type of implanted lens, complications of cataract surgery, time interval between cataract surgery and the development of D.R., pre-operative and postoperative visual acuity and type of operation of D.R. In the group there was a significant ratio of men (71.4%), the mean age was 60.28 years and 78.6% of the patients were referred to our department. Phaćoemulsification with implantation of IOL was made in 57% of the patients, extracapsular extraction with implantation of IOL in 47%. The authors did not find a significant difference between the type of cataract surgery with regard to the development of D.R. A posterior chamber intraocular lens was implanted in 71% eyes of the group while an anterior chamber intraocular lens was used only in 29% of the eyes in the group. Complications of cataract surgery were above all ruptures of the posterior capsule (64%). Dislocation of the lens into the vitreous body during surgery was recorded only in one case (7%) a non-complicated operation of cataract was recorded in 28%, incl. one case (7%) where D.R. was preceded by laser capsulotomy. The mean time interval between cataract operation and D.R. was 20.7 months. The visual acuity before surgery of D.R. was 0.24 while after surgery it was 0.31. In 50% patients a cryosurgical procedure was used in operation of D.R., pars plana vitrectomy as the first operation of D.R. was used in 50% of the group. Adherence of the retina after the first operation was achieved in 64.2% eyes, after re-operation in 85.7% eyes. The authors did not find a significant difference between the type of cataract surgery and type of implanted lens as regards anatomical and functional results of surgery of D.R. Proliferative vitreoretinopathy and dysfunction of the photoreceptors were the main cause of anatomical and functional failure the operation of D.R. in the group. The number of pseudophacic D.R. after laser capsulotomy did not exceed the number of D.R. after non-complicated cataract surgery in the investigated group.

Cataract Extraction↗
PubMed2001

[Effect of cataract surgery on contrast sensitivity].

The authors examined in a group of patients with cataract the visual acuity on Snellen's optotypes and contrast sensitivity using Pelli-Robson's test before cataract surgery and after cataract extraction and implantation of an intraocular lens. A VF-7 questionnaire was used for subjective evaluation of the result of surgery. The values of contrast sensitivity of the pseudophakic eyes were compared with the contrast sensitivity of eyes of a age-matched control group with a natural lens. After cataract surgery and lens implantation highly significant improvement of visual acuity of the operated eye was recorded. There was also significant improvement of binocular contrast sensitivity in the study group. The authors did not detect a significant difference of the contrast sensitivity of eyes with a PMMA lens and eyes with a silicone lens. There was no significant difference in the contrast sensitivity of pseudophakic eyes and phakic eyes of the control group. The CF-7 questionnaire revealed that cataract surgery led to significant improvement of the investigated visual activities, as apparent from the subjective evaluation by the patients. However, no significant correlation was found between objective (contrast sensitivity) and subjective (VF-7 questionnaire) evaluation of cataract surgery. Only one question in the questionnaire correlated significantly with contrast sensitivity. The authors found a significant reduction of contrast sensitivity caused by an altered transparency of the lens. The decline of contrast sensitivity in eyes with cataract and relatively good vision on Snellen's optotypes is the cause of some subjective complaints of the patients and may be an important factor in indication of cataract surgery of eyes with a relatively good visual acuity.

Aged↗
PubMed2000

[Phacoemulsification in chronic closed-angle decompensated glaucoma].

The author followed up the medium-term results of cataract operations in five patients with decompensated closed angle glaucoma. From the results ensues that in patients with an intraocular pressure of less than 30 mm Hg surgery of cataract alone has a positive effect on the compensation of glaucoma. An advantage is also the standard surgical technique. The operation is made on an eye with a narrower pupil and requires an experienced ophthalmosurgeon.

Aged↗
PubMed2000

[Ultrastructure of the lens capsule in pseudoexfoliation syndrome].

The authors examined, using transmission electron microscopy, the lenticular capsule obtained during phacoemulsification by circular capsulorrhexy in pseudoexfoliation syndrome. The assembled findings indicate degenerative changes of the lenticular capsule, manifested by destruction of the surface layer.

Exfoliation Syndrome↗
PubMed1999

[Vitreoretinal surgery in diabetic patients in a dialysis program].

Pars plana vitrectomy in patients with severe renal and retinal affections was considered a relative contraindication for operation. Despite relative failure (deterioration of visual acuity) it is possible in these patients, and in half of them it improved their quality of life. The risk of peroperative and postoperative damage can be reduced by suitable selection of anticoagulants. The favourable effect of tamponade with silicon oil on the postoperative course must be tested in a controlled trial.

Adult↗
PubMed1999

[Transmission electron microscopy of the surface of an intraocular lens removed from the eye].

The authors examined by transmission electron microscopy the surface of an intraocular posterior chamber lens explanted from the eye of a female patient on account of secondary glaucoma. They found a fibrous reaction in particular at the site of contact of the supporting haptic with the sulcus of the ciliary body which was the cause of failure of conservative treatment.

Female↗
PubMed1999

[Removal of silicone oils from the eyes after vitrectomy].

The author describes his experience with elimination of silicone oil in 60 patients. The follow-up period was 4 to 16 months. In 30% of patients where the retina adhered, removal of the oil was associated with improved visual acuity and quality of vision. In 5%, on the other hand, removal of silicone oil was associated with reoperation of a relapse of detachment of the retina as the operation proved ineffective and the finding on the retina did not change. In 3% patients who had only one functional eye there was a subjective deterioration of vision. Before removal of silicone oil in adverse cases it is always necessary to consider carefully the risks of a relapse of detachment and deterioration of visual functions.

Adult↗
PubMed1994

[Personal experience with scleral fixation in posterior chamber intraocular lenses].

The authors give an account of their experience with scleral fixation of posterior chamber intraocular lenses by a stitch into the ciliary sulcus. The fixation was made in two patients as a secondary implantation, in eight patients on account of rupture of the posterior lenticular capsule during extracapsular extraction of cataract and in two instances after a perforating injury of the eye and anterior vitrectomy. In two instances a subluxated cataract was involved.

Humans↗