Objective Accommodation Amplitude Measurements Using a New Autorefractometer Device

Objectives: To measure the value of objective accommodation amplitude (AA) in patients using the new autorefractometer device and to evaluate the effects of age, refraction errors, pupil diameter on objective AA measurements. Methods: Three hundred subjects who were divided into five groups according to age were enrolled in this study. AA and pupil diameter were measured three times from both eyes using Tonoref III (NIDEK Co., Ltd.). Results: The mean AA was 1.6325±0.061 Diopter (D) (0.13-9.11 D). The mean AA values were statistically significantly different between the groups (p=0.000). It was not observed gender effect on AA (p=0.115). Although there was no significant difference between emmetropic and myopic groups, there were significant differences between emmetropic and hyperopic groups and also between myopic and hyperopic groups concerning AA (p=0.000, for both). A statistically significant difference was found for the mean AA between the groups with and without refractive surgery (p=0.028). Correlation analysis revealed that AA is increased as the mean pupil diameter increases (p=0.000, r=0.202) and the mean pupil diameter decreases with increasing age (p=0.000, r=-0.308). When the AA obtained from the patients in group 1 were compared with the AA values obtained by subjective accommodation tests, the AA values obtained by autorefractometer device were found to be correlated with push up, push down and minus lens tests (r=0.577, r=0.682, r=0.427) AA values obtained by autorefractometer device were found to be statistically significantly lower than other subjective tests (p< 0.001). Conclusion: The Tonoref III device seems to provide objective AA measurements in presbyopic or non-presbyopic individuals. Age, refractive error, pupil diameter and history of refractive surgery were effective on AA values, while the gender was not effective

Objective Accommodation Measurements In Different Ages By Using An Autorefractometer

Introduction: To measure accommodation amplitude (AA) at different ages by using Tonoref 3 (NIDEK CO., LTD.) and to investigate a possible correlation with pupil diameter. Material and Methods: AA was measured in both eyes of 125 subjects between 25 and 69 years of age by using Tonoref 3. Pupil diameter was also measured at the same time with AA measurement. All measurements were repeated 3 times and for test–retest reliability, the same protocol was repeated on 3 additional days as well as twice on the same day in the young adults and the average values were collected for statistical analysis. Subjects were grouped into 10-year bins, and a descriptive univariate analysis of the data performed. Results: The mean age was 37.82 years ±1.72 (SD). The mean AA was 1.6682±0.1841 (range 0.14-8.06). In order to investigate the relationship between age and AA, the age data is divided into three groups as 30 and under, 30-39, 40 and above. A significant difference was found between 30 and 40 age above groups and 30-39 and 40 age and above (p=0.000, for each). A negative correlation was found between age and AA. In addition, a weak correlation was found between pupil diameter and AA. Conclusions: The accommodative responses measured with Tonoref 3 were significantly suitable for objective measurement of accommodation with varying ages. Pupil diameter has a weak effect on the measurement of AA

Topometric and Tomographic Evaluation of Subclinical Keratoconus

Purpose: To investigate the corneal topometric and tomographic findings that can be used in the diagnosis of subclinical keratoconus. Methods: A retrospective cohort study. The study group was selected from patients with clinically evident keratoconus in one eye and subclinical keratoconus without evident topographic findings in fellow eye. The age-matched control group was selected from patients who were candidates for laser in situ keratomileusis (LASIK) and did not develop ectasia after LASIK surgery at least 1-year follow-up. All subjects underwent topographic, topometric and tomographic (Belin-Ambrósio Enhanced Ectasia Display III) analyses via a Pentacam HR rotating Scheimpflug camera (Oculus, Germany, version 1.20r.98) before LASIK surgery. Results: The study group consisted of 151 patients (69 male and 82 female, mean age of 24.8 ± 7.2 years) and the control group also consisted of 150 patients (70 male and 80 female, mean age of 26.0 ± 6.3 years). There were statistically significant differences in all measured topometric (p?.05) and tomographic (p?.001) parameters between the eyes with subclinical keratoconus and those of the control group. In discriminating eyes with subclinical keratoconus from normal eyes, final D showed the highest area under curve value (0.858, sensitivity 85.2%, specificity 66.7%), followed by maximum pachymetric progression index (0.809, sensitivity 81.9%, specificity 69.4%) and average pachymetric progression index (0.796, sensitivity 81.9%, specificity 68.1%) in receiver operating characteristic analysis. Conclusion: Topometric and tomographic parameters might be useful for early detection of keratoconus, but the sensitivity and specificity of any parameter are not high enough to be used alone

Sıkı Glisemik Kontrolü olan Tip 1 Diabetes Mellituslu Çocuklarda Yüksek Sıralı Korneal Aberrasyonların Değerlendirilmesi

Purpose: To compare the higher-order corneal aberrations of Type 1 Diabetes Mellitus (DM) children who have well controlled glucose level with healthy children of similar age and gender. Methods: After performing a complete ophthalmological examination of children with Type 1 DM (DM group) and similar age-matched healthy controls (Control group), higher order corneal aberration values [coma, trefoil, spherical aberration, higher order root mean square (RMS), total RMS] were measured by Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany). Results: There were 52 patients (29 males, 23 females) in the DM group and 39 (20 males, 19 females) volunteers in the control group. In the DM group, the mean preprandial blood glucose level was 86.4 ± 8.2 mg/dl and the mean HbA1c value was 5.2 ± 0.75%. The mean age of the DM group was 12,64 ± 3,75 years while it was 11,94 ± 4,09 years in the control group. There was no statistically significant difference in age and gender between the two groups (p = 0.745, p = 0.364 respectively). No statistically significant differences were found between the groups according to higher order corneal aberrations [coma, trefoil, spherical aberration, high order root mean square (RMS), total RMS] (p=0,415, p=0,690, p=0,642,p=0,0840, p=0,647, for each one). Conclusion: Higher order aberrations of the cornea do not change in children whose blood glucose levels are well controlled