Abstract: Glaucoma and dry eye - incidence & risk factors

30 to 40+ % is pretty staggering when you think about it. It ought to be far more than sufficient to induce glaucoma doctors and general ophthalmologists to sit up and pay more attention to what they're prescribing to their glaucoma and ocular hypertension patients.

Risk factors to develop ocular surface disease 
in treated glaucoma or ocular hypertension patients.

Purpose.
To identify risk factors for developing ocular surface disease (OSD), to verify the prevalence of OSD, and to record efficacy of questionnaires in identifying symptoms' impact on patients' quality of life.
 Methods.
This was an observational, cross-sectional study of patients with topically treated glaucoma. Tear film break-up time (TFBUT) and punctate keratitis were evaluated; 2 quality-of-life questionnaires (National Eye Institute-Visual Function Questionnaire 25 and Glaucoma Symptom Scale) were submitted to all patients. Class of previous and current intraocular pressure (IOP)-lowering drugs, number of drugs, number of drops/day, and total and current benzalkonium chloride (BAK) exposure were collected.
 Results.

A total of 233 patients completed the study. TFBUT was abnormal in 71 (30.5%) eyes; punctate keratitis was present in 74 (31.7%). Keratitis was more frequent with increasing number of eyedrops (p = 0.008) and number of instillations per day (p = 0.009). Ocular surface disease was present in 97 (41.6%) patients and was statistically related to number of medications used (p = 0.026). The univariate analysis pointed out that patients with OSD were older (p = 0.04), had lower IOP values (p = 0.03), were topically treated for more time (p < 0.0001), had assumed more BAK (p < 0.0001), and presented worst quality of life (p < 0.01). The multivariate analysis found that OSD was related to number of medications used (p = 0.002), prolonged use of preserved medications (p = 0.005), and total BAK exposure  (p < 0.001).

Conclusions.
There is clinical evidence that the number of medications, their prolonged use, and the total BAK exposure are risk factors to develop OSD in patients with glaucoma. To prevent OSD onset, BAK exposure and the number of topical medications should be reduced.

Eur J Ophthalmol. 2012 Dec 17:0. doi: 10.5301/ejo.5000220. [Epub ahead of print]

Rossi GC, Pasinetti GM, Scudeller L, Raimondi M, Lanteri S, Bianchi PE.

University Eye Clinic, Fondazione IRCCS Policlinico S. Matteo, Pavia - Italy.