The purpose of this study is to assess the association of retinal detachment (separation of the retina [the innermost layer of the eyeball] from its connection at the back of the eye) with exposure to oral ciprofloxacin or oral fluoroquinolones.

This is an observational (in which the investigators observe the outcomes of the study participants but do not intervene by, e.g, assigning the treatments) and retrospective (a study in which the exposures and outcomes occurred before the study began) study. It will use data from the Optuminsight and Truven Commercial Claims and Encounters databases, each of which will be evaluated separately using 3 designs: (1) Case-control (a design that compares the cases [study participants], ie, those with retinal detachment to controls, ie, a sample of similar people who did not have a retinal detachment) to assess whether their exposures to fluoroquinolones (FQs) differed. Two case-control studies are planned, one (replication) that mimics a previously reported study, the other (revised) that addresses more potential confounders than did that study , (2) Cohort (a design that follows the participants exposed to FQs and those not exposed to FQs to assess whether the two groups had different risks of developing retinal detachment), (3) Case-only (a design where the exposure history of individuals who had retinal detachment are examined to assess whether they were more likely to have had it when they were exposed to FQs than when they were not).

Inclusion criteria:

• At least 1 year of enrollment in the study for medical and pharmacy benefits after their cohort (group) entry (the day of their first ophthalmologist visit) for case-control design
• Oral fluoroquinolone like levofloxacin or ciprofloxacin must be dispensed to participants for cohort design
• At least one visit to an ophthalmologist and enrolled at least for 1 year in the study for medical and pharmacy benefits prior to the date of first occurrence of the exposure of levofloxacin or ciprofloxacin for cohort design
• At least one visit to an ophthalmologist and enrolled at least for 1 year in the study for medical and pharmacy benefits prior to the diagnosis of their first retinal detachment (separation of the retina [the innermost layer of the eyeball] from its connection at the back of the eye) for case-only design

Exclusion criteria:

- Prior diagnosis of retinal detachment , prior diagnosis or procedure for inflammatory conditions of the eyeball, or hospital admission between cohort entry and the date of the retinal detachment

Participants with exposure to oral fluoroquinolones