Possible Beneficial Effects Of Combined Fluoxetine And Occlusion Therapy In Improving And Maintaining Vision In Amblyopia Using Optical Coherence Tomography Angiography (OCTA) And Visual Evoked Potential (VEP). The Aim Of The Study Is To Evaluate Possible Beneficial Effects For Different Age Groups.

Study Design:

• A prospective clinical non-randomized comparative controlled study.

Ethical Consideration:

All patients and control subjects included in this study were verbally briefed about the details and the nature of the study. Informed consent was obtained from all patients included in the study. The study was approved by local ethical committee of Minia University Faculty of Medicine and was adherent to the tenets of Declaration of Helsinki and the approval number was 1288/2024.

Study Population:

Study participants will be recruited from the ophthalmology outpatient clinics of Minia University Hospitals. Imaging will be performed in the Department of Ophthalmology, Minia University Hospital.

Study will include 75 eyes that will be divided into 3 groups:

Group A: normal eyes of age-matched controls. Group B: amblyopic eyes treated with patching. Group C: amblyopic treated with patching and flouxetine.

Ophthalmic Examination:

All patients will undergo a thorough ocular and systemic history taking, as well as a comprehensive ophthalmic examination before, 3 months after patching and fluoxetine therapy and 3 months after therapy withdrwal, including:Uncorrected visual acuity (UCVA).

• Best corrected visual acuity (BCVA) by Snellen's chart transformed to log MAR chart.
• Manifest and cycloplegic refraction using auto refractometer (Nidek CO, Japan).
• Intraocular pressure (IOP) by air puff tonometry (TOPCON computerized tonometer CT-800, Japan).
• Anterior segment examination using slit-lamp bio-microscopy (Sunkingdom LS-3, Germany).
• Dilated Fundus examination using slit lamp bio-microscopy using a +78 diopter condensing lens and peripheral retinal examination by means of binocular indirect ophthalmoscopy.

Investigations:

Ophthalmic imaging:

OCT-A (Optovue Inc. Fremont, CA, USA).

OCT-A technique:

OCT-A scans were done using AngioVue OCTTM system on RTVue XR 100 Avanti spectral domain-OCT device, version 2015 (Optovue Inc, Fremont, CA, USA).

Technique:

• OCT-A was done in dim light following appropriate pupillary dilation using cyclopentolate 1% eye drops (Plegica, Hikma) and patient data were entered and the examination type was selected from the machine software.
• The patient was asked to place the chin on the chin rest, forehead against the forehead rest, eye to be scanned aligned horizontally with the canthus mark, and to look inside the imaging aperture.
• The patient was asked to look at the fixation target, a blue dot in the red field.
• The patient's eye was placed at the center of the video picture, and the working distance between the scanning head and the patient's eye was adjusted to improve the video image. The scan head was then slowly advanced nearer till fundus image sharpened.
• The scan signal strength index (SSI) was optimized to be ≥ 50.
• After instructing the patient to stare at the center of the blue target, pictures were recorded by pressing the joystick or checkmark button.

OCT-A print out:

The print out of the gray scale angiovue retinal scan included:

Across the top, four angiovue en-face images at different depths:

• Superficial layer: including vasculature from the nerve layer and GCL.
• Deep layer: include both intermediate and deep inner retinal vasculature.
• Outer retina: lying between OPL and RPE
• Choriocapillaris: include the inner layer of choroidal blood vessels At lower left, an OCT en-face image overlaid with an angiovue image that indicate the angiovue scan area. At the lower right, horizontal and vertical B scan images, each en-face angiovue image has green horizontal and red vertical lines that indicate the current B-scan location; we can drag these lines to select which horizontal and vertical B-scan display.

In this study, OCT-A parameters that were compared in this study include vessel density in SCP, DCP and chorio-capillaris layers in either the whole image of central 6 mm, foveal and para-foveal regions as well as FAZ area.

Flash VEP (FVEP) and pattern VEP (PVEP) Ophthalmic functional assessment by FVEP and PVEP will be performed for all patients before, 3 months after patching and fluoxetine therapy and 3 months after therapy withdrwal. FVEP and PVEP will be done using the (Roland Consult supercolor Ganzfeld Q450 SC).

FVEP Ganzfeld

Requirement:

• Light-adapted patient (photopic conditions)
• Pupils non dilated
• 3 x EEG-Electrodes at channel 1
• One eye covered with Impedance < 10 kOhm PVEP

Requirement:

• Distance patient → monitor: 100 cm
• Light-adapted Patient (photopic conditions)
• Patient refraction / correction for 100 cm viewing distance
• 3x EEG-Electrodes at channel 1 One eye covered
• Impedance < 10 kOhm Outcome Measures

1. Comparison of VA between 3 groups.
2. Comparison of vessel density (VD) of FAZ, superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) between 3 groups in OCTA.
3. Comparison of FVEP and PVEP between 3 groups:

• FVEP: latency and amplitude of P2.
• PVEP: latency and amplitude of P100.

Statistical Analysis:

Data analyses were performed using statistical package for the social science (SPSS) software version 26. Demographic and outcome data were presented as mean± standard deviation for continuous variables with normal distribution.

Categorical variables were reported as frequency (sex). Shapiro-Wilk test and Kolmogorov Simonov test were performed to test the normality of the data. One way ANOVA test was done to compare results between 3 groups and a two sided p < 0.05 was considered as statistically significant.