Personal Identity and Self-Interpretation & Natural Right and Natural Emotions

Collection of papers presented at the 2nd and 3rd Budapest Seminar in Early Modern Philosoph

Intraoperative and postoperative corneal thickness change after collagen crosslinking therapy.

PURPOSE To assess intraoperative and postoperative changes in corneal thickness subsequent to riboflavin-UVA (collagen crosslinking [CXL]) treatment. METHODS Forty-one eyes of 41 patients (mean age 27.97 ± 6.97 years) were treated with CXL technique. During treatment, isotonic riboflavin was instilled and corneal thickness measurements were obtained at the cornea apex, the thinnest point, and the pupil center at 15 and 30 minutes, then 3 days, 1 week, and 1, 3, 6, and 12 months after surgery using Pentacam HR and an ultrasound pachymeter. RESULTS A decrease in corneal thickness was detected 15 minutes intraoperatively with a value of 108.95 ± 48.6 µm, and 112.35 ± 47.3 µm at 30 minutes (p<0.001). Three days after the operation, no deviation was found from the initial values (p = 0.17). No further changes were detected during the follow-up period. CONCLUSIONS Isotonic riboflavin solution used during CXL treatment resulted in a significant decrease in corneal thickness, but its effect had disappeared by postoperative day 3

Examination of ocular biomechanics with a new Scheimpflug technology after corneal refractive surgery

PURPOSE To analyze the early results of a new device measuring ocular biomechanics after corneal refractive surgery. PATIENTS AND METHODS Thirty nine refractive surgery patients were enrolled in the study (age: 32.6±9.9 years). Laser in situ keratomileusis (LASIK) was performed on 52 eyes of 26 patients and photorefractive keratectomy (PRK) was done on 26 eyes of 13 patients. Ten device-specific biomechanical parameters, intraocular pressure (IOP) and pachymetry were measured preoperatively and at day 1, week 1 and month 1 after the surgeries with a new technology based on Scheimpflug imaging (CorVis ST, Oculus). RESULTS In case of LASIK, the day after the procedure, radius values showed significant differences compared to preoperative data. One month after surgery, radius values, velocity of the second applanation and pachymetry showed significant differences compared to preoperative data. In case of PRK, the day after the procedure, significant differences in IOP, maximum amplitude at the apex, A1 time, A2 velocity and highest concavity time were measured. After 1 month of PRK, there were no differences in the parameters compared to preoperative data except pachymetry. CONCLUSIONS We observed that some specific biomechanical parameters changed measured with CorVis ST after LASIK and PRK, in the early postoperative time. However, most of these parameters remain unchanged after one month of LASIK and PRK compared to preoperative data

Accommodation in phakic and pseudophakic eyes measured with subjective and objective methods

PURPOSE To measure accommodation subjectively and objectively and assess anterior segment changes during accommodation in phakic eyes and pseudophakic eyes. SETTING Department of Ophthalmology, Medical Health and Science Centre, University of Debrecen, Debrecen, Hungary. DESIGN Case series. METHODS Subjective and objective accommodation measurements and pupillometry were performed in phakic and pseudophakic patients. Refraction and pupil diameter were recorded with different accommodation stimuli. Corneal higher-order aberrations (HOAs) and anterior chamber depths (ACDs) were detected with a rotating Scheimpflug camera. RESULTS The mean age of the 44 patients in the phakic group was 36.34 years ± 16.6 (SD) and of the 27 patients in the pseudophakic group, 69.3 ± 9.98 years. The mean subjective accommodation was 4.49 ± 3.48 diopters (D) in phakic eyes and showed significant correlation with age, spherical aberration, changes in pupil diameter, and ACD. The mean subjective accommodation was 0.50 ± 0.28 D in pseudophakic eyes. In phakic eyes, the mean objective accommodation was 0.46 ± 1.02 D, 1.06 ± 1.33 D, and 2.2 ± 1.9 D with 2.0 D, 3.0 D, and 5.0 D, respectively, of stimulus. In pseudophakic eyes, measurable objective accommodation was recorded. In phakic eyes, the correlations were significant between these values and age, changes in ACD, pupil size, and corneal spherical aberration. In pseudophakic eyes, the only correlation was with the spherical equivalent value. CONCLUSIONS The magnitude of accommodation was greater with subjective measures than objective measures. In pseudophakic eyes, senile miosis and HOAs can be regarded as underlying factors in subjective accommodation; however, objective accommodation is not clinically significant. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned

Scheimpflug imaged corneal changes on anterior and posterior surfaces after collagen cross-linking

<b>AIM:</b> To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.<b>METHODS:</b> Collagen cross-linking was performed in 31 eyes of 31 keratoconus patients (mean age 30.6±8.9y). Prior to treatment and an average 7mo after therapy, Scheimpflug analysis was performed using Pentacam HR. In addition to corneal thickness assessments, corneal radius, elevation, and aberrometric measurements were performed both on anterior and posterior corneal surfaces. Data obtained before and after surgery were statistically analyzed.<b>RESULTS:</b> In terms of horizontal and vertical corneal radius, and central corneal thickness no deviations were observed an average 7mo after operation. Corneal higher order aberration showed no difference neither on anterior nor on posterior corneal surfaces. During follow-up period, no significant deviation was detected regarding elevation values obtained by measurement in mm units between the 3.0-8.0 mm-zones.<b>CONCLUSION:</b> Corneal stabilization could be observed in terms of anterior and posterior corneal surfaces, elevation and higher order aberration values 7mo after collagen cross-linking therapy for keratoconus