How do Extended Depth of Focus (EDOF) lenses compare to multifocal lenses in terms of glare and intraocular side effects in patients undergoing intraocular lens implantation?

EDOF vs Multifocal IOLs: Glare and Intraocular Side Effects

EDOF lenses produce significantly fewer photic phenomena (glare and halos) compared to multifocal IOLs, making them the preferred choice for patients who prioritize quality of vision and are willing to accept slightly reduced near vision performance. 1

Key Differences in Visual Disturbances

Glare and Halo Incidence

• EDOF lenses demonstrate markedly lower rates of photic phenomena: only 6% of eyes experience halos and glare at 6 months compared to 65% with multifocal IOLs 1

• Multifocal IOLs result in statistically significant increases in both glare (risk ratio 1.36,95% CI 1.15-1.61) and halos (risk ratio 3.14,95% CI 1.63-6.08) compared to monofocal lenses 2

• The American Academy of Ophthalmology explicitly states that multifocal IOLs result in "reduced contrast sensitivity and an increased incidence of haloes" 3

Mechanism Behind Reduced Side Effects

• EDOF technology creates a single elongated focal point rather than multiple discrete foci, which is the fundamental reason for reduced photic phenomena compared to multifocal designs that divide incoming light into two or more focal points 4, 3

• This optical design minimizes the light splitting that causes the characteristic glare and halos seen with multifocal IOLs 4

Contrast Sensitivity Comparison

• Contrast sensitivity is significantly better preserved with EDOF lenses compared to multifocal IOLs 1

• Both multifocal and EDOF lenses show some reduction in contrast sensitivity compared to monofocal IOLs, but the reduction is more pronounced with multifocal designs 3

Visual Performance Trade-offs

Distance Vision

• No clinically significant difference exists between EDOF and multifocal IOLs for uncorrected distance visual acuity 1

Intermediate Vision

• EDOF lenses provide superior monocular visual acuity at intermediate distances (80 cm) compared to multifocal lenses 1

Near Vision

• Multifocal IOLs achieve better uncorrected near vision (40 cm) than EDOF lenses, with a mean difference of -0.26 logMAR favoring multifocals 2
• EDOF lenses provide functional near vision but may require occasional reading glasses for sustained near tasks 1

Spectacle Independence

• Multifocal IOLs provide the highest rate of complete spectacle independence (0% requiring glasses) compared to EDOF lenses (35% requiring glasses) 1

• However, this comes at the cost of significantly higher photic phenomena that may impact quality of life, particularly for night driving 1

Patient Selection Algorithm

Choose EDOF lenses for patients who:

• Drive frequently at night or work in low-light conditions where glare would be problematic 1
• Prioritize quality of vision over complete spectacle independence 5
• Require excellent intermediate vision for computer work or digital device use 1
• Have lower tolerance for visual disturbances 5

Choose Multifocal lenses for patients who:

• Prioritize complete spectacle independence above all else 1
• Rarely drive at night or work in challenging lighting conditions 1
• Are willing to accept visual compromises including glare and halos 3
• Have realistic expectations about photic phenomena 5

Critical Counseling Points

• All patients considering presbyopia-correcting IOLs must receive preoperative counseling about potential visual disturbances, with specific emphasis that multifocal lenses carry substantially higher risk than EDOF designs 5

• The American Academy of Ophthalmology emphasizes that selection depends on "the patient's visual needs, expectations, motivation to be less dependent on eyeglasses, and willingness to accept potential compromises" 3

• Patients should understand that while EDOF lenses minimize photic phenomena, they may still require reading glasses for sustained near work, whereas multifocal lenses provide better near vision but with significantly more visual side effects 1

Important Caveats

• The incidence of photic phenomena with EDOF lenses (6%) is only slightly higher than monofocal lenses (0%) but dramatically lower than multifocal lenses (65%) 1

• Newer diffractive multifocal designs show improved outcomes compared to older refractive designs, but still demonstrate higher rates of halos and glare than EDOF technology 2

• EDOF lenses must demonstrate at least 0.5 diopters greater depth of focus than monofocal controls under standardized testing conditions including photopic, mesopic, and glare conditions 3