Myopic astigmatism and presbyopia trial

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Presbyopia affects near vision, and astigmatism may theoretically improve depth of focus.
• No prior studies have prospectively evaluated the impact of low astigmatism on presbyopic patients.

Purpose of the Study:

• To determine if low myopic astigmatism (1 diopter) benefits or harms visual acuity, stereopsis, or quality of life in presbyopic patients.
• Investigate the effects of spherical (SPH), with-the-rule (WTR), and against-the-rule (ATR) astigmatism in presbyopia.

Main Methods:

• Prospective, randomized, double-masked, crossover clinical trial involving 15 presbyopic patients (aged 45-68).
• Patients wore masked soft contact lenses with SPH, 1D WTR, or 1D ATR astigmatism for 1 week each.
• Outcomes included visual acuity (distance, intermediate, near), stereoacuity, and quality of life (RSVP).

Main Results:

• Visual acuity was similar across all conditions, though intermediate vision was slightly better with SPH correction.
• Near stereopsis was superior in the ATR astigmatism group (50 seconds) compared to WTR (102 seconds).
• Patients reported a slight preference for SPH over WTR astigmatism in quality of life scores (RSVP).

Conclusions:

• Low myopic astigmatism (1D) did not enhance visual acuity or quality of life in presbyopic patients compared to spherical correction.
• Intermediate visual acuity and overall quality of life were marginally better with spherical correction.
• While ATR astigmatism improved near stereopsis, it did not translate to better near visual acuity or quality of life.