[Corneal cross-linking--modern method of keratoconus treatment]. / Corneal cross-linking--moderná metóda liecby keratokónusu.

PURPOSE: The aim of research study was to evaluate the effect of corneal cross-linking (CXL) in the frame of patients with progressive keratoconus 1 year after treatment. METHODS: There were 40 eyes of 35 patients with mean age 28, 45 +/- 9.3 (SD) (15 to 48 years) included in the study. Patients were treated with standard protocol of CXL with abrasion of corneal epithelium. Complete ophthalmological examination included best corrected spectacles visual acuity (BCSVA), slit-lamp microscopic finding, corneal topography and corneal thickness measured with ultrasound method was performed before, on the 5-th day, 1. 6., 12. month after CXL. We divided patients according to the stage of keratoconus into 2 groups (stage I. and stage II.) and according to the age into 3 groups (until 20, from 21 to 39, over 40 years). RESULTS: In all treated eyes, the CXL was without relevant complications. The only complication was stromal haze of cornea. In the evaluation based on stage of keratoconus, in the first group any patient became a haze of cornea in 1 year after CXL. In the second group 35.7% of patients had a haze of cornea. The average BCSVA 1 year after treatment was improved in the 1. group about 5.38 letter and in the 2. group about 1.25 letter. Topographic analysis showed decrease of simulated keratometry and refraction (1. group--0.1 D, 2. group--0.17 D), maximal keratometry and refraction (1. group--0.67 D, 2. group--0.76 D). Minimal keratometry and refraction in the 1. group decreased (1.17 D) and increased in the 2. group (1.09 D). In the evaluation based on the age was haze monitored in the first group one year after CXL in 12.5% of researched eyes. In the second group was haze of cornea in 20% of eyes and in the third group consisting of patients over 40 years old, in 50% of eyes. The average BCSVA was improved in the 1. group (2.85 letter), and in the 2. group (3.68 letter).The average BCSVA was decreased in the oldest patients in about 1.43 letter. In the 1. and 2. group the topographic analysis showed decrease of simulated keratometry and refraction (1. group--0.12D, 2. group--0.21D), maximal keratometry and refraction (1. group--1.13 D, 2. group--0,68D), minimal keratometry and refraction (1. group--1.17D, 2. group--0,69 D). In the 3. group the topography analysis showed increase of simulated keratometry and refraction (0,8D), maximal keratometry and refraction (0,98D), minimal keratometry and refraction (0,28D). Corneal pachymetry remained stable in all researched groups of patients. CONCLUSIONS: CXL is considered as safe procedure to stop progression of keratoconus also for patients until 19 years old. The best effect and minimal complications were by patients until 40 years old and by patients with the I. grade.

[Contrast sensitivity and higher order aberration after conventional LASIK treatment]. / Kontrastní citlivost a aberace vyssích rádu po konvencním LASIKu.

AIM: The aim of the prospective study was to evaluate photopic high-contrast visual acuity, mesopic contrast sensitivity, and high order aberrations, to compare changes and post-operative development of those parameters and to analyze the dependence among aberrations and contrast sensitivity after conventional LASIK treatment. MATERIALS AND METHODS: The authors followed-up patients treated by means of refractive LASIK treatment during the period from November 2006 to November 2007. The authors analyzed 51 eyes (31 patients). The average age of the group was 28.5 +/- 5.4 years (range, 18 - 41 years), preoperative average spherical equivalent was -4.95 +/- 1.24 D (from -3 to -8,25 D). Before the treatment and 1, 3, 6, and 12 months after LASIK treatment we evaluated the visual acuity (Snellen optotypes), contrast sensitivity under mesopic circumstances (CSV-1000E, VectorVision) and monochromatic aberrations (aberometer Zywave, Bausch & Lomb). RESULTS: One year after the treatment the average uncorrected visual acuity was 1.07 +/- 0.15, index of effectiveness 0.99, and index of safety 1.02. The contrast sensitivity was in month 12 significantly decreased comparing to the preoperative level at the frequency 12 c/deg, in other already tested frequencies after 3-6 moths did not differed from preoperative values. During the follow-up period the curvature of contrast sensitivity average values was in the upper half of the normal interval range. Conventional LASIK treatment significantly induced the higher order aberration (twice), as well as the spherical aberration (four times).The same level of higher order aberrations root mean square (HOA-RMS), or increased maximally by 0.1 microm was detected by 10 % of cases; the spherical aberration was, compared to the preoperative value, lower, or increased maximally by 0.05 microm in almost one half of the cases. The increase of the higher order aberrations depended directly proportionally to the preoperative value of the spherical equivalent. Before the treatment, the values of total aberrations correlated to the contrast sensitivity of low space frequencies; however, there was not found any correlation between the higher order aberrations and contrast sensitivity. Six months after the LASIK treatment the values of higher order aberrations correlated to the contrast sensitivity except of the lowest frequency tested. The higher order aberrations increased together with decreasing contrast sensitivity. The data from the one-year follow up control did not show statistically significant correlation between the contrast sensitivity and the higher order aberrations. There was not found any correlation between the contrast sensitivity and the spherical aberration at any follow-up control after the surgery. CONCLUSION: Although after the conventional LASIK treatment the curve of mesopic contrast sensitivity was located in the upper half of the normal range, in the medial space frequency it remained decreased comparing to the preoperative stage. The induction of higher order aberrations was twice as much and was directly correlated to the degree of the laser correction. The spherical aberration was four-times higher comparing to the preoperative values and was independent to the level of the initial refractive error. Significant correlation between the contrast sensitivity and the higher order aberrations was not proven.

[Changes of higher order aberrations and contrast sensitivity after standard photorefractive keratectomy]. / Zmeny aberací vyssích rádu a kontrastní citlivosti po standardní fotorefrakcní keratektomii.

UNLABELLED: The aim of the prospective study was to evaluate higher order aberrations and contrast sensitivity after photorefractive keratectomy (PRK) using the standard photoablation profile. MATERIALS AND METHODS: The group consisted of 37 patients (69 eyes), the mean age 27.2 +/- 4.5 years, who underwent PRK with target emetropia during the period January 2007 -December 2007. In 19 cases, it was correction of myopia, in 50 cases myopia with astigmatism.The preoperative spherical equivalent was -3.14 +/- 0.95 D. The PRK was performed by means of excimer laser system Technolas 217 (Bausch & Lomb) with the standard phoptoablation profile (PlanoScan 2000), using the 6.5 mm optical zone. The visual acuity, contrast sensitivity (CS; CSV-1000E, VectorVision) under mesopic circumstances and monochromatic aberrations (Zywave, Bausch & Lomb) were evaluated before the surgery, and 1,3, 6, and 12 months thereafter. The pair t-test, Wilcoxon test, and the Mann - Whitney U test (alpha = 0.05) were used for the statistical analysis. RESULTS: The PRK showed high index of effectiveness and safety (0.98, respectively 1.03 in the first year after the procedure). The contrast sensitivity under mesopic circumstances was not significantly involved after the PRK. The main value of the CS remained during the whole follow-up period within the physiological range in all spatial frequencies. Postoperatively, the part of spherical aberration on the higher order aberrations increased from 13.1% preoperatively to 16.6% one year after the PRK. In one half of the cases, the change of the higher order aberrations was within the range +/- 0.1 microm. In 66% of cases, the change of the spherical aberration was +/- 0.05 microm. The higher order aberrations comparing to the preoperative values decreased or remained unchanged approximately in one third of the cases, and the spherical aberration in one quarter of the cases. There was not established dependence between monochromatic aberrations values and the contrast sensitivity. CONCLUSION: Although the conventional RPK for low myopia treatment induces higher order aberrations including the spherical aberration, the impact on the contrast sensitivity under mesopic circumstances in our group were not significant. The contrast sensitivity of the most of patients was near the upper limit of the normal range.

[Applying the DNA diagnostics in patients with superficial keratitis of viral origin]. / Vyuzití DNA diagnostiky u pacientu s povrchovou keratitidou virového puvodu.

AIM: The authors evaluate the significance of the DNA diagnostics in patients with superficial keratitis of viral origin and their capability to be used for monitoring of the treatment effectiveness in the follow-up. The presence of herpes simplex virus 1 and 2, varicella zoster virus (HSV 1, HSV 2, VZV), and adenoviruses was assessed by means of the DNA analysis. MATERIAL AND METHODS: The group consisted of 54 patients (33 men and 21 women), mean age 45.6 +/- 9.5 years, who were treated at the Eye Department for superficial keratitis or keratouveitis of viral origin. A sample from the involved place was taken with a cotton swab and a sample of approx. 50 microL of tears was taken from the conjunctival sac with a single-use micropipette. The cotton swab and the tears were shaken with the EliDNA Store Kit (ELISABETH PHARMACON, Czech Republic) buffer, which prevents the DNA degradation and allows the storage and transport of samples at the room temperature. After the transportation in to the laboratory, the DNA was isolated by means of the UltraClean DNA Tissue Kit (MoBio, U.S.A.). The isolated DNA was used for HSV 1, HSV 2, VZV, and adenoviruses detection by means of PCR (polymerase chain reaction). All samples were screened for the HSV1 presence using the in-house RealTime method with TaqMan probe and the Applied Biosystems RealTime System 7300 device. In case of positive result of the DNA analysis, control samples were taken in 7 - 10 days periods until negative result was obtained; another sample was taken in case of suspected relapse. The control examination was also performed by means of cultivation from the same sample by another laboratory. RESULTS: Altogether 82 samples were taken and 230 DNA analyses were performed. The DNA diagnostics proved the presence of HSV 1 DNA in 28 patients, in one case, VZV DNA was detected, and 16 patients were positive on adenoviruses. The HSV 1 positive samples were confirmed by means of in-house RealTime PCR method as well as commercially available in vitro diagnostic healthcare device End-Point PCR HSV1/2 (Nanogen Advanced Diagnostics, Italy). All cultivation control examinations performed in another laboratory were negative. The samples were taken repeatedly in 9 patients to monitor the efficacy of the treatment. SUMMARY: The DNA diagnostics seem to be a fast and reliable method to determine the etiological agent in patients with superficial keratitis and allow very accurate monitoring of the treatment efficacy.

[Long-term results of the postoperative ametropia correction after perforating keratoplasty using the LASIK method]. / Dlouhodobé výsledky korekce pooperacní ametropie po perforující keratoplastice metodou LASIK.

The postoperative refractive error after otherwise successful perforating keratoplasty (PK), often negatively influents the visual acuity.The authors refer about the results of postoperative ametropia correction by means of the LASIK method. There were 43 eyes of 38 patients in the study group. In 41 eyes, there was myopia with myopic astigmatism, and in two eyes, the hyperopia with hyperopic astigmatism were present. The average age of the group was 35.6 +/- 10.5 years (24-87 years), and the follow-up period was 27.4 +/- 22.9 months (maximum, 95 months). The average spherical refractive error before the LASIK procedure was -2.67 +/- 3.66 D, and preoperative subjective astigmatism -5.14 +/- 2.81 Dcyl. The average astigmatism established by means of corneal topography was 5.16 +/- 2.45. Dcyl. LASIK was performed during one session using the excimer laser Keracor 117 (Chiron) or Technolas 217 (Bausch & Lomb). For the lamellar keratectomy the authors used the mechanical LKS (Moria) and the automatic ACS keratome (Chiron). For the corneal topography examination, the ORBSCAN II (Bausch & Lomb) machine was used. The authors evaluated 1) the development of the postoperative refraction, 2) the change of the axis of the astigmatism induced by LASIK, 3) the development of the uncorrected visual acuity (UCVA), 4) the final uncorrected and best-corrected visual acuity (UCVA and BCVA), 5) the change of the endothelial cells' density after LASIK, and 6) the occurrence of per- and postoperative complications. At the last postoperative control, the average of the spherical refractive error was -0.17 +/- 1.01 D, subjective astigmatism was -1.58 +/- 2.03 Dcyl, and topographical astigmatism was 3.62 +/- 2.06 Dcyl (t-test, p < or = 0.001). We reduced the spherical refractive error by 93.6%, subjective astigmatism by 69.3%, and topographical astigmatism by 29.8% only. In 14 eyes (32.6%) the change of the axis was recorded--so called surgically induced astigmatism--the average value was 30.8 +/- 19.8 degrees (t-test, p > or = 0.05). The final UCVA 0.5 and better was reached by 74.4% of eyes (t-test, p < or = 0.001) and BCVA 0.5 and better in 83.8% of eyes (t-test, p < or = 0.05). The postoperative UCVA improved according to the preoperative one in 95.3% of cases, the BCVA in 37.2% of cases (by means of gain of lines on the Snellen chart). During the follow-up period the authors didn't prove statistically significant decrease of the endothelial cells' density (CD) according to the LASIK procedure (t-test, p > or = 0.05). Peroperatively, the authors noticed small defect of the lamella 4 times, and total lamellar detachment 2 times. Postoperatively, in 6 eyes a slight fibrosis occurred, and in two cases, the late rejection of the corneal transplant was diagnosed. The keratoconus relapsed 12 months after the procedure in 2 eyes and was indicated to rekeratoplasty. LASIK is an effective and relatively safe method for postoperative refractive error correction after perforating keratoplasty.

[Comparison of the efficiency and safety of the two methods, LASIK and ICL in mild and high hyperopia correction--part two]. / Srovnání efektivity a bezpecnosti metody LASIK a implantace ICL pri korekci stední a vysoké hyperopie. II. cást.

The problems of mild and high hyperopia surgical correction are complicated and an individual approach is needed. The aim of the study was to evaluate long-term efficiency and safety of two types of refractive procedures in mild and high hyperopia correction: LASIK and ICL (phakic intraocular posterior chamber contact lens) implantation. The authors evaluated a group of 37 eyes of 20 patients; the average age was 36.3 years +/- 11.8 (SD) and the follow-up period was 28.1 months +/- 10.2 (SD) after LASIK procedure, and a group of 21 eyes of 13 patients; the average age was 28.6 years +/- 6.1 (SD) and the follow-up period 30.4 months +/- 20.9 (SD) after the ICL implantation. They compared occurrence of preoperative, intraoperative and postoperative complications in both methods. They specified the efficiency and safety of the procedure by means of so called efficiency and safety index. With a questionnaire they evaluated the patient's subjective satisfaction with the refractive procedure. In the group of hyperopic LASIK, they proved statistically significant appearance of the refractive error regression, number of performed re-operations, appearance of the peroperative decentration of the photoablation zone and induced astigmatism (p < 0.05). In the ICL group, the repeated preoperative sessions for Nd-YAG laser iridotomies were necessary. Postoperatively, the appearance of keratitis striata, syndrome of the late pigment dispersion, and glare were statistically significant (p < 0.05). The authors also demonstrated higher efficiency and safety of the ICL implantation method comparing to LASIK during the whole follow up period (p < 0.05), and also higher subjective satisfaction after ICL implantation. Comparing the intraocular procedure (ICL) to the laser method (LASIK), in mild and high hyperopia correction, the higher efficiency and safety was achieved by ICL implantation.

[Comparison of the two methods, LASIK and ICL in mild and high hyperopia correction--part one]. / Srovnání metody LASIK a implantace ICL pri korekci strední a vysoké hyperopie. I. cást.

The problems of hyperopia surgical correction are complicated. The most used methods are corneal laser treatments (PRK and LASIK), phakic intraocular lenses or clear lens extraction (CLE). The aim of the study was to evaluate and to compare long-term postoperative results of two types of refractive procedures in mild and high hyperopia correction: LASIK and ICL (phakic intraocular posterior chamber contact lens) implantation. The authors evaluated a group of 37 eyes of 20 patients; the average age was 36.3 years +/- 11.8 (SD) and the follow-up period 28.1 months +/- 10.2 (SD) after LASIK procedure, and group of 21 eyes of 13 patients; the average age was 28.6 years +/- 6.1 (SD) and the follow-up period 30.4 months +/- 20.9 (SD) after the ICL implantation. The final uncorrected (UCVA) and best-corrected visual acuity (BCVA) and postoperative refractive error (for far and near) and their development in time were compared. They found statistically significant improvement of the UCVA postoperatively comparing to the preoperative values in both methods (LASIK and ICL) (p < 0.05). Better UCVA was achieved by means of ICL implantation (p < 0.05). The BCVA improved after the ICL implantation only (p > 0.05). In hyperopic LASIK, the final BCVA worsened comparing to this before treatment (p > 0.05). The BCVA changes were not statistically significant. The authors also proved better final spherical refraction for far (p < 0.05 in the first and second year) and for the near as well (p < 0.05 in the first and second year) in the ICL method comparing to the hyperopic LASIK. The stableness of the postoperative refraction was better after the ICL implantation during the whole follow up period. In the laser treatment, the continuous regression of the postoperative refraction was evident. The final cylindrical refraction value was also lower in the ICL group (p > 0.05). The stableness of the postoperative cylindrical refraction was also higher in the ICL method during the whole follow up period. Comparing the intraocular procedure (ICL) to the laser method (LASIK), the ICL implantation demonstrates better final BCVA and UCVA and the postoperative refraction is more stable.

[The methods of analysis of the endothelial microscopy]. / Metody analýzy endoteliální mikroskopie.

AIM: To compare results of classical and digital analysis of the corneal endothelium. MATERIAL AND METHODS: We evaluated a group of 36 eyes with physiological findings of the anterior segment of the eye; the average age of examined persons was 32.8 years (SD +/- 9.5). The examination was performed by means of non-contact specular microscope SP 1000 TOPCON. The obtained finding was evaluated by means of (i) classical analysis, (ii) automatic digital analysis, and (iii) revised digital analysis. The result of the classical analysis is the cellular density (number of cells/mm2). The digital analysis is made possible by means of the connection of the specular microscope with the computer program IMAGENET. The Endothelial Analysis System evaluates furthermore the coefficient of the cellular area variation (%), and the hexagonality (%). The normality of the values' distribution was evaluated by means of the test Liliefors, subsequently the paired t-test or nonparametric Wilcoxon's test were used. RESULTS: Comparing results of the automatic to the revised digital analysis, statistically significant difference in all evaluated parameters was found (P = 0.01). The average cells' density calculated by means of classical analysis (2643 +/- 347) is by 3 % smaller than the value established by means of revised digital analysis (2718 +/- 330 cells/mm2). Regardless of that, no statistically evident difference was found at the 1% level of significance. In 13 cases the revised digital analysis showed lower values than the classical one, whereas in 23 cases the overestimation by revised digital analysis up to 501 cells/mm2 was found. To complete the classical analysis or the automatic digital analysis, it takes in average 7-8 minutes. The time needed to examine one sample of endothelium using the revised digital analysis was in the examined group 25-30 minutes. CONCLUSION: Although there is no statistically significant difference (P = 0.01) between the revised digital analysis and the classical analysis, and between both methods there is statistically significant dependence (r = 0.82); it is necessary to consider their incomplete compatibility in case of results' interpretation in a single patient. The revised digital analysis is rather more time consuming, but supplies more information about the status of the endothelial single layer.

[Calculation of diopter value of the IOL in simultaneous cataract surgery and perforating keratoplasty]. / Výpocet dioptrické hodnoty IOL pri soucasne provedené operaci katarakty a perforující keratoplastice.

PURPOSE: To evaluate the successfulness of intraocular lens (IOL) power calculation and refractive error after the triple procedure. METHODS: During the period 1995-2004, the triple procedure was performed in 51 eyes of 43 patients aged 29-83 years (mean 66 years) with corneal disease and cataract. For the IOL power calculation, the SRK II formula was used. In case of impossibility to measure the keratometry, the data from the other eye, or the value 7.7 mm were used. The donor cornea was punched by trephine with the diameter 0.50 mm (in 88.2% of eyes) or 0.25 mm (in 11.8% of eyes) larger than for the recipient cornea. In 30 eyes (58.8%), the interrupted suture was used, in 21 eyes (41.2%) the running suture was employed. In 33% of eyes, the PMMA IOL was implanted, in 18 eyes (35.3%) the hydrophilic acrylate IOL. The final refraction and visual acuity was evaluated 13 - 24 months (mean, 17.1 months) after the surgery, and always after the suture removal. RESULTS: The best-corrected visual acuity (BCVA) ranged 0.1 - 1.0 (mean, 0.4 +/- 0.2). BCVA 0.5 or better was achieved in 26 eyes (51.0%). The spherical equivalent of postoperative refractive error less or equal to 2 dioptres was achieved in 35 eyes (68.6%) and ranged from 0.0 to 3.6 dioptres (mean, 1.4 +/- 1.1 dioptres). CONCLUSION: According to the final refraction of the eye, the use of our method of IOL power calculation in the triple procedure is satisfying and its results are comparable with results published in the literature.