The Impact on Vision of Aspheric to Spherical Monofocal

Intraocular Lenses in Cataract Surgery

Journal Reading

A Systematic Review with Meta-analysis

OLLY CONGGA

ADVISOR:dr. HAMZAH, Sp.M(K)

MODERATOR:dr. AHMAD ASHRAF, MPH, Sp.M(K), M.Kes

COMMENTATOR:DR. dr. NORO WASPODO, Sp.M

PurposeTo provide a summary of the impact on vision of an aspheric intraocular lens (IOL) compared with a spherical IOL in cataract surgery

DesignSystematic review with meta-analysis

ParticipantsPatients from published randomized controlled trials (RCTs) of cataract surgery with aspheric compared with spherical monofocal IOL implantation

MethodsPeer-reviewed literature in MEDLINE, EMBASE, Web of Science, BIOSIS, and the Cochcrane Library according to the COchrane Collaboration method to identify relevant RCTs

The inclusion criteria were assessed visual acuity (BCVA), contrast sensitivity, or quality of vision

The effects were calculated as mean differences or standardized mean differences (Hedges' g) and pooled using random-effect models

Main Outcome MeasuresBest-corrected visual acuity (BCVA), contrast sensitivity, and subjective perception of the quality of vision

Results43 studies, comprising 2076 eyes implanted with aspheric IOLs and 2043 eyes implanted with spherical IOLs.

BCVA showed a significant difference for aspheric IOLs (-0.01 LogMAR; 95% CI, -0.02 to 0.00)

Contrast sensitivity, a significant advantage for aspheric IOLs was found under photopic and mesopic light conditions (photopic: Hedges' g 0.42, 95% CI 0.24-0.61 [3 cpd] to 0.53, 95% CI 0.33-0.73 [12 cpd]; mesopic: Hedges' g 0.49, 95% CI 0.23-0.75 [1.5 cpd] to 076, 95% CI 0.52-1.00 [18 cpd])

ConclusionsA patient may achieve better contrast sensitivity with an aspheric IOL tahn with a spherical IOL, especially under dim light.No clinically difference in BCVA between aspheric and spherical IOL implantation.The subjective perception of visual acuity were heterogeneous with no clear result favoring either option

JOURNAL THEORY• Spherical Abberation

JOURNAL THEORY Aspherical to Spherical Monofocal IOLs

Designed to reduce or eliminate the Designed to reduce or eliminate the spherical aberration & improve spherical aberration & improve functional vision as compared with a functional vision as compared with a spherical pseudophakic implantspherical pseudophakic implant

Market in the USA : Tecnis IOL, Market in the USA : Tecnis IOL, AcrySof IOL, SofPort IOLAcrySof IOL, SofPort IOL

JOURNAL THEORY Meta-analysis

A statistical technique for combining the findings from independent studies

most often used to assess the clinical effectiveness of healthcare interventions → combining data from two or more randomised control trials.

The validity depends on the quality of the systematic review on which it is based

offers a rational and helpful way of dealing with a number of practical difficulties that beset anyone trying to make sense of effectiveness research

BACK TO JOURNAL

Intraocular LensesIntroduction

Methods

Results

Discussion

Conclusion

Designed to replace the crystalline lens Aspheric design of the IOL optic → counterbalance the positive asphericity of the prolate cornea Minimization of abberation → optimization of the retinal image quality Perceived net effect of the asphericity → continuously been disputed

Introduction

Methods

Results

Discusssion

Conclusion

Procedures → Systematic review (MEDLINE, EMBASE, Web of Science, BIOSIS, & Cochrane Library Database)Database keyword → aspheric, intraocular lens, presudophakia, & cataract surgeryData collection → A.K.S & J.T.Eligibility Criteria & Outcome variables → BCVA (logMAR scale), contrast sensitivity

Assessment of the study quality → sequence generation, allocation concealment, blinding of participants & outcome assessors, management of eventual incomplete outcome data, completeness of outcome reporting, other potential threats to valdity

Statistical Analysis → Mean differences for BCVA, standardized Hedges' g for contrast sensitivity, DerSimonian-Laird random effects model to compare & combine the different studiesHeterogeneity management → TECNIS, AcrySof IQ

Methods

Results

Discussion

Conclusion

Introduction•Figure 1. Preferred Reporting Items for Systematic Reviews & Meta Analysis flow diagram.

•Figure 2. Overall effect on BCVA. Forest plot showing the mean difference in logMAR of postoperative BCVA when comparing the implantation of aspheric with spherical IOLs

•Table 2. Photopic Contrast Sensitivity Measurement at Different Spatial Frequencies

•Table 3. Mesopic Contrast Sensitivity Measurements at Various Spatial Frequencies

•Table 4. Summary of Quality of Vision as Reported in Validated Questionnaries

Introduction

Methods

Discussion

Results

Conclusion

Data on BCVA → aspheric IOL implantation provided a significant advantage The effect in terms of BCVA was small → only 2 of 38 studies found a statistically significant improvement Overall, beneficial effect is only small The data do not suggest that the effect of aspheric IOL implantation would clinically outperform spherical IOL implantation based on BCVA

Contrast sensitivityphotopic light condition → significant effect at

the spatial frequencies between 3 & 18 cpd, not < 18 cpd

better with aspheric IOL at all spatial frequencies under mesopic light conditions, effect size were moderate to large, strongest effect at 18 cpd

Reducing spherical abberation → reducing myopic shift & increasing contrast sensitivity Questionnaires → subjective assessment of visual perception → primary outcome in meta-analysis

Introduction

Methods

Results

Discussion

Conclusion

Data from meta-analysis do not indicate a clinically relevant impact on BCVA from aspheric vs spherical IOL implantation. However, the meta-analysis confirmed improved photopic and, to a greater degree, mesopic contrast sensitivity though the aspheric IOL → such a visual benefit for individuals for particularly high mesopic vision requirements. The findings with regard to the subjective perception of visual quality are still heterogeneous when standard questionnaires are used. Overall, aspheric IOL implantation might be a good choice for patients with high demands in terms of contrast vision

Thank you