The goal of this retrospective study is to evaluate the historical effectiveness of Riboflavin-Enhanced Hyaluronic Acid Eye Drops (HAr® 0.1%) in the treatment of Dry Eye Disease (DED) among patients. The product under investigation, Ribohyal®, had previously obtained certification and authorization from the relevant notified body for market sale (European patent n. 2228058)

The primary questions it aimed to address were:

• Did the use of Riboflavin-Enhanced Hyaluronic Acid Eye Drops result in a reduction of dry eye symptoms and an improvement in ocular comfort among patients with DED in a historical context?
• Was Riboflavin-Enhanced Hyaluronic Acid Eye Drops historically more effective in reducing photophobia and enhancing tear film stability when compared to standard treatment?

Participants in this retrospective analysis had historically:

• Used either Riboflavin-Enhanced Hyaluronic Acid Eye Drops or a standard hyaluronic acid eye drop, based on their assigned group.
• Historically reported their levels of ocular discomfort and photophobia at specified time points.
• Undergone historical clinical examinations to assess tear film stability and osmolarity.

Researchers conducted a retrospective analysis to compare the historical outcomes of the group using Riboflavin-Enhanced Hyaluronic Acid Eye Drops with the group using standard eye drops to determine if the former historically provided more significant improvements in dry eye symptoms and tear film stability.

In this retrospective study, the investigators have examined the historical therapeutic efficacy of Riboflavin-Enhanced Hyaluronic Acid Eye Drops (HAr® 0.1%) in the treatment of Dry Eye Disease (DED), adhering to good clinical practice principles.

Participants were historically divided into two groups:

• Group X: received Riboflavin-Enhanced Hyaluronic Acid Eye Drops (HAr® 0.1%) (Ribohyal Group).
• Group Y: received standard HA 0.1% eye drops (Control Group).

The historical outcome measures included the retrospective assessments of osmolarity, Tear Break-Up Time (TBUT), corneal staining, Schirmer test, tear meniscus measurement, and Non-invasive Break-Up Time (NIBUT). The Ocular Surface Disease Index (OSDI) score was historically recorded at various time points.

Inclusion criteria for patient selection included a dry eye history of at least three months, OSDI score ≥ 23, and positivity in at least one eye for one or more of the following diagnostic criteria:

• Tear Break-Up Time (TBUT) < 7 seconds
• Schirmer test I at 5 minutes < 10 mm
• Corneal and/or conjunctival fluorescein staining
• Tear osmolarity > 308 mOsm/L or a difference of at least 8 mOsm/L between both eyes.

Exclusion Criteria:

• Age below 18 years
• Severe ocular surface affections
• Unilateral dry eye syndrome
• Refractive surgery performed within the last six months
• Eye surgery performed within the last three months
• Previous herpetic keratitis
• Signs of active corneal infection
• Systemic or topical steroid therapy within the last 30 days
• Topical therapy within the last 14 days
• Inability to understand the informed consent.

The study enrolled 16 consecutive patients with bilateral mild to severe Dry Eye Disease (DED) at the University of Naples Federico II, Italy. These participants were selected based on specific eligibility criteria, as outlined in other sections of the study. The selection aimed to ensure that the study population adequately represented individuals experiencing DED.

all collected IPD, available on request