Safety and Efficacy of Different Add Powers With a New Presbyopic Lasik Treatment Algorithm

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under photopic light conditions.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under photopic light conditions.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under photopic light conditions. Corrected means spectacle corrected.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under photopic light conditions. Corrected means spectacle corrected.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 80 cm (intermediate distance) in LogMAR scale under photopic light conditions.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 80 cm (intermediate distance) in LogMAR scale under photopic light conditions.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 40 cm (near distance) in LogMAR scale under photopic light conditions.

The visual acuity measurements will be assessed using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) at 40 cm (near distance) in LogMAR scale under photopic light conditions.

To assess the visual acuity for different distances, defocus curves under photopic light conditions will be measured using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) device at 4m. This test is performed with best distance corrected refraction and spherical additions ranging from -4.5 D to +1.0 D in 0.5D steps.

The contrast sensitivity test consists in assessing the possibility to distinguish the alternation of white and grey fringes of difference contrast with difference frequency. Contrast sensitivity will be assessed under photopic and mesopic light conditions using Clinical Trial Suite (M&S Technologies, Niles, IL, USA) device at 2.5 m.

The amount and disturbance of photic halo side effects will be assessed by two methods: 1) Halo and Glare simulator: With this software tool the particant mimics the individual vision perception by adjusting a typical night scene image with the intensity and size of glare and halo; 2) Siepser Glarometer (Gulden Ophthalmics, Elkins Park, PA 19027). This is a target-like device that measures and quantifies post-operative glare. The measurement is of the participants' actual scope and range of monocular glare and halo.

The amount and disturbance of photic glare side effects will be assessed by two methods: 1) Halo and Glare simulator: With this software tool the particant mimics the individual vision perception by adjusting a typical night scene image with the intensity and size of glare and halo; 2) Siepser Glarometer (Gulden Ophthalmics, Elkins Park, PA 19027). This is a target-like device that measures and quantifies post-operative glare. The measurement is of the participants' actual scope and range of monocular glare and halo.

The Patient-Reported Spectacle Independence Questionnaire (PRSIQ) is comprised of 3 questions about the need for glasses or contacts in the past 7 days for distance vision (at least 1.5 meters (m) away), intermediate vision (0.5 m to 1.5 m away), and near vision (< 0.5 m away). Possible scores range from 1 to 5, with 1 = All of the time and 5 = None of the time for six of the questions; 3 of these questions ask the question in a positive way and 3 of the question ask the question in a negative way, so the higher scores are better for the negative question and are worse for the positive question. There are also 3 questions whether glasses or contacts were needed in the past 7 days with scores of Yes = 1 and No = 2. The results for each question will be summarized separately.

The Near Activity Visual Questionnaire (NAVQ) is comprised of 10 questions about performing activities without extra reading spectacles. Each question has responses of 0 to 4, with 0 indicating 'No difficulty' and 4 indicating 'Extreme difficulty'. Any 'Not applicable' responses are scored according to the median overall score for the subject. The scores are summed with total score ranging from 0 to 30. Higher scores indicate more difficulty performing specified activities without spectacles.