Contribution of medical expert reports as technical evidence in judicial decisions on pterygium surgeries: a jurisprudential analysis from 1997 to 2022 in the state of São Paulo

Abstract

Pterygium is a triangular fibrovascular subepithelial growth extending from the conjunctiva onto the cornea. In advanced cases it may cause astigmatism, ocular irritation, and visual impairment, often requiring surgical removal. Pterygium excision is indicated when the lesion threatens the visual axis or produces significant symptoms; however, the procedure carries a substantial risk of recurrence if proper techniques are not employed (recurrence rates can reach ~50–60% without appropriate surgical methods). In this context, unsatisfactory outcomes or complications may lead to malpractice lawsuits. This study examines the influence of court-ordered medical expert reports on judicial decisions in such cases. A jurisprudential review was conducted of the São Paulo State court from 1997 to 2022, identifying 34 appellate judgments exclusively related to pterygium surgeries. All cases involved judicial medical expert examinations aimed at clarifying disputed technical issues. The results show a high degree of alignment between expert findings and court verdicts: in 88% of the analyzed cases, the judges’ decisions were consistent with the experts’ conclusions, indicating that, in most instances, the courts ruled in accordance with the forensic reports. In 100% of the cases in which the expert found a medical error, the defendant was held liable, underscoring the decisive weight of expert evidence when negligence is established. Conversely, in 12% of cases (4 lawsuits) discrepancies were observed: although the expert report did not find malpractice, the court’s decision still imposed liability on the physician or healthcare institution. Notably, there were no cases in which the expert identified an error and the defendant was acquitted. Conclusion: Expert technical evidence plays an essential role in clarifying allegations of error in pterygium surgery and decisively contributes to judicial reasoning. The strong correspondence between expert opinions and verdicts demonstrates that judges usually rely on forensic reports when forming their conclusions. However, cases resulting in liability despite the absence of expert-identified fault suggest that other legal factors may influence judicial outcomes – such as distinct theories of civil liability (strict vs. fault-based), breach of the duty of informed consent, or the principle of the judge’s free evaluation of evidence. Overall, this study highlights the importance of integrating Legal Medicine and Law: while qualified forensic medical examinations provide indispensable technical grounding for the courts, final judgments may also reflect legal reasoning beyond strictly scientific evidence. Attention to these divergent cases and further dialogue on how to balance expert evidence and broader legal standards are recommended to ensure fair and well-substantiated rulings.