Determination of proteins and their levels in the vitreous of eyes with or without pseudoexfoliation syndrome (PEX)

Pseudoexfoliation syndrome (PEX) is a systemic disorder that leads to the deposition of extracellular material in various tissues, particularly in the anterior segment of the eye. This material consists mainly of elastic microfibrils. PEX is believed to be an age-related condition whose incidence and prevalence vary by region but increase in patients over 50 years of age. Due to demographic changes, the number of PEX patients is expected to rise, making it important to understand this condition, its pathogenesis, and its complications.

The pathogenesis of PEX syndrome has not yet been fully elucidated. The interplay of growth factors, oxidative stress, inflammation, and cellular damage is described as a key factor in the development of the disease. Detailed immunohistochemical and biochemical studies have shown that several proteins are heavily involved in the pathogenesis of PEX.

The anterior segment of the eye is frequently affected by PEX, where the PEX material is present in the aqueous humor, and its accumulation leads to visible deposits on the anterior lens capsule, the edge of the pupil, or the anterior chamber angle. Several proteomics studies of the aqueous humor have been conducted, demonstrating that oxidative stress and inflammation contribute to the development of PEX. However, there is a lack of studies on PEX and its effects on the posterior segment. Some studies suggest that the posterior segment is primarily affected. Interestingly, PEX has recently been linked to diseases/pathologies of the vitreoretinal interface (VRI). It has been shown that the rates of posterior vitreous detachment (PVD) and epiretinal membranes (ERM) are higher in eyes with PEX.

The pathogenesis of ERM is not fully understood, but similar to PEX, inflammation, inflammatory proteins, and cytokines appear to play an important role in the development of ERM.

To further investigate the differences in proteins and their levels in the vitreous humor of PEX and non-PEX eyes, the aim of the study is to perform a non-targeted proteomic analysis using liquid chromatography coupled with mass spectrometry (LC-MS) of the vitreous humor from PEX eyes with ERM, compared to vitreous humor without PEX but with ERM.

Inclusion Criteria:

• PEX syndrome
• Macular pucker or macular hole and scheduled for vitrectomy
• Age 21 or older
• Written informed consent prior to surgery

Exclusion Criteria:

• Previous vitrectomy or intravitreal application of drugs
• Systemic anti-inflammatory drugs
• Pre- surgical topical anti-inflammatory drugs (NSAR, Steroids)
• Pre- surgical topical prostaglandins
• Diabetic retinopathy
• AMD
• PEX Syndrome only in the contralateral eye (the eye not scheduled for surgery)