IOL Selection and Refractive Targeting: When Good Intentions Lead to Litigation

In modern cataract practice, intraocular lens (IOL) selection and refractive targeting sit at the intersection of clinical judgement, patient expectation, and medico-legal risk. While surgeons may approach these decisions with technical confidence and good intent, litigation frequently arises when refractive outcomes diverge from what the patient anticipated or understood.

This blog is written for surgeons, medical experts, and those involved in medico-legal assessment. It explores how IOL selection and refractive planning are examined retrospectively by the court, and why technically competent surgery may still give rise to claims when expectation management and documentation are inadequate.

Refractive Targeting Is No Longer a Secondary Consideration

Historically, cataract surgery was framed as a sight-restoring procedure. Increasingly, patients view it as refractive surgery, with expectations of spectacle independence or precise visual outcomes.

This shift has changed how courts view refractive planning. IOL selection and target refraction are no longer peripheral technical decisions. They are central to patient autonomy and informed decision-making.

Expert witnesses are often asked to assess not only whether the chosen IOL was reasonable, but whether the refractive aim itself was appropriately discussed and agreed.

The Choice of Refractive Target Is Patient Specific

A common misconception in litigation is that a single refractive target represents a default standard. In practice, refractive targets must be individualised.

Factors that should inform refractive planning include:

• dependence on the fellow eye

• occupational and lifestyle visual demands

• tolerance of anisometropia

• willingness to use spectacles

• pre-existing ocular pathology

• prior refractive history

Failure to explore these factors can lead to refractive dissatisfaction even when biometry and surgery are technically sound.

First-Eye Outcomes and Second-Eye Planning

One of the most scrutinised areas in bilateral cataract cases is how the outcome of the first eye informed planning for the second.

Expert analysis often focuses on whether:

• the refractive result of the first eye was reviewed critically

• prediction error was acknowledged

• the refractive target for the second eye was adjusted

• further discussion with the patient took place

Proceeding with an identical plan despite an unexpected first-eye outcome may be difficult to defend if no reassessment or discussion is documented.

Biometry Limitations and Refractive Uncertainty

Modern biometry is highly accurate, but not infallible. Courts increasingly expect that patients are informed about refractive uncertainty, particularly in the presence of:

• extreme axial lengths

• prior corneal refractive surgery

• corneal irregularity

• ocular surface disease

• dense cataract affecting measurements

Expert witnesses must consider whether refractive unpredictability was foreseeable and whether this was communicated clearly.

Premium IOLs and Heightened Expectation

The use of toric, multifocal, or extended depth of focus lenses introduces additional medico-legal complexity. While these lenses may offer advantages, they also carry specific risks that require careful counselling.

Issues commonly examined include:

• dysphotopsia

• reduced contrast sensitivity

• intolerance of optical phenomena

• the need for explantation or exchange

• residual refractive error

When premium lenses are involved, courts often scrutinise whether the consent process adequately addressed trade-offs as well as benefits.

Documentation as a Reflection of Decision-Making

In litigation, documentation becomes the proxy for the consultation itself. Where refractive discussions are not recorded, courts may infer that they did not occur.

Common documentation deficiencies include:

• no record of refractive aim

• absence of discussion about spectacle dependence

• no note of alternatives such as monovision or deferral

• no reference to refractive uncertainty

Clear, contemporaneous documentation is often decisive in defending IOL-related claims.

Causation and Refractive Dissatisfaction

Unlike cases involving vision-threatening complications, refractive disputes often turn on whether the patient would have made a different choice if properly informed.

Expert witnesses are frequently asked to address:

• whether the refractive outcome was within an acceptable range

• whether dissatisfaction equates to harm

• whether alternative targets would likely have produced a better functional outcome

• whether the patient would have declined surgery or chosen differently

This analysis requires careful avoidance of hindsight bias.

Teaching Point for Surgeons and Experts

IOL selection and refractive targeting fail medico-legally not because of technical incompetence, but because the decision-making process is not sufficiently visible.

For surgeons, structured refractive discussions and documentation reduce risk.For expert witnesses, understanding refractive planning pathways is essential to provide balanced, court-assisting opinion.

Conclusion

IOL selection and refractive targeting represent one of the most nuanced areas of cataract litigation. As patient expectations rise, courts increasingly focus on how refractive decisions were discussed, documented, and adapted.

When refractive planning is treated as a shared decision rather than a technical default, outcomes are more defensible and patient autonomy is better respected. For expert witnesses, this area demands clarity, balance, and deep understanding of both clinical practice and legal scrutiny.