The cross-sectional observational clinical study related to rare eye diseases is a multi-center study in which the hypothesis is that neurokinin 1 receptor and/or substance P expression is increased in REDs associated with inflammation/pain. Moreover, the following alternative targets are: VEGF, PAX6 and pro-inflammatory cytokine.

The following procedures are performed specifically for the study: samples of blood, tear fluid and impression cytology.

Precisely during the ophthalmological exam performed according to normal clinical practice (uncorrected visual acuity, best spectacle corrected visual acuity, corneal topography, corneal pachymetry and the slit lamp pictures) investigator's team collect the samples of blood, tear fluid and impression cytology to evaluate the goal of the study.

Inclusion Criteria:

Inclusion Criteria for study group

• Women and men with age equal or higher than 18 years (patients in reproductive age may be included in the study).
• Willingness and ability to read and understand the informed consent.
• Diagnosis (including genotype, if needed) of REDs.

Inclusion Criteria for control group

• Women and men with age equal or higher than 18 years (patients in reproductive age may be included in the study).
• Willingness and ability to read and understand the informed consent.
• Non - diagnosis of REDs.

Exclusion Criteria:

Exclusion Criteria for study group

Patients who meet these criteria will be excluded from participation in the study:

• Pregnancy, breastfeeding.
• Active ocular infection.
• Descemetocele/impending corneal perforation.
• Recent (less than 3 months) ocular surgery.
• Recent (less than 1 month) change in topical medications type and frequency.

Exclusion Criteria for control group

Patients who meet these criteria will be excluded from participation in the study:

• Pregnancy, breastfeeding.
• Active ocular infection.
• Descemetocele/impending corneal perforation.
• Recent (less than 3 months) ocular surgery.
• Recent (less than 1 month) change in topical medications type and frequency.

The study population consists of 137 patients, each of them will present with one of the 7 diseases under study (REDs).

The control group will consist of 137 patients not presenting the previous reported REDs.