The effect of anti-glaucoma medications on the ocular surface.

This promotional topic was presented by Dr Ravin N Das on 21-08-05 at Hotel Satya Ashoka. The program was sponsored by Avesta Division of Sun Pharma.

Introduction

Increased chances of dry eye in glaucoma patients due to:

• Dry eye prevalence 6% at 40 years age to 15% at 65.
  
• Lower basal tear turnover in Glaucoma (Kuppens et al. AJO 1995)
  
• Topical therapies promote OSD
  

Topical therapies promote OSD

• Corneal and conjuctival epitheliopathy (Inou et al. Glaucoma 2005)
  
• Low grade conjunctival inflammation (Baudolin et al. Ophthalmology 1994; Noeker Cornea 2004)
  
• Epithelial apoptosis (Debbasch et al. IOVS 2001; Pisella et al. IOVS 2004)

Punctate epitheliopathy

Conjunctival inflammation - 1

Conjunctival inflammation - 2

 

Prior Glaucoma surgery
Leading to an altered lid-globe relationship:-

• Bleb
  
• Shunt
  

Bleb - 1

Bleb - 2

Shunt

Ocular surface effects

• Irritation related symptoms
  
• Unstable tear film
  
• Blurred and fluctuating vision
  
• Altered corneal barrier -
  
  • stromal haze (colored haloes)
    
  • infiltrates
    
  • corneal ulceration
    

Management

• Eliminate offending agents - toxic drops & preservatives.
  
  • Oral CAI (not always possible)
    
• Minimize preservative exposure.
  
  • Non-preserved Timolol/Brimonidine
    
  • Lower BAK concentration (0.005 to 0.02%)
    
  • Purite® preserved Timolol/Brimonidine
    
  • Switch to combinations - reduce exposure to preservatives (applicable to patients on multi-drug therapy).
    
• Preserve tears
  
  • puntal occlusion - may exacerbate corneal preservative toxicity.
    
• Decrease ocular surface inflammation
  
  • Steroids & NSAIDS
    
  • Tetracycline
    
  • Cyclosporine
    
    • non-preservative
      
    • good lubricant due to base
      
    • doesn't raise IOP
      
    • inhibits apoptosis of cornea and conjunctival epithelium.
      

   

Summary

Dry eye is prevalent in glaucoma patients.

Multifactorial:-

• reduced tear production
  
• altered tear distribution
  
• ocular surface disease from medication and preservative toxicity (due to epitheliopathy, conjunctivalinflammation and epithelial apoptosis)
  

Treatment requires:-

• Elimination of offending agents
  
• Improve or preserve tear turnover
  
• Decrease inflammation/apoptosis
  

Suggested remedy: Use preservative free (Purite® preserved) anti-glaucoma medications whenever possible...