Virtual Reality Simulators and Case Volume Emerge as Key Drivers of Surgeon Training Success

Every year, thousands of ophthalmology residents around the world take up the delicate task of learning to operate on the human eye, where incisions are measured in millimeters and a single misstep can permanently alter a patient’s vision. A new systematic review published in BMC Medical Education has now pulled together the scattered evidence on how these surgeons-in-training actually acquire their skills, and how the medical community judges whether they are ready to operate independently. The review, led by Luksanaporn Krungkraipetch and colleagues at Burapha University in Thailand, offers one of the most structured syntheses to date of a field that has long relied on tradition, apprenticeship, and intuition rather than rigorous educational science.

The research team followed the PRISMA 2020 reporting guidelines, the international standard for conducting and reporting systematic reviews in health care. They searched four major electronic databases, PubMed, Scopus, the Cochrane Library, and ERIC, in December 2025, casting a wide net across the medical education literature. From an initial pool of 4,233 records, only twelve studies published between 2007 and 2022 ultimately met the strict inclusion criteria. To qualify, studies had to evaluate surgical training outcomes among ophthalmology residents, covering measures such as intraoperative or postoperative complications, surgical efficiency, case-volume and learning-curve effects, surgical success, trainee competency, or the impact of simulation-based training. Research on non-residency populations or on educational interventions unrelated to surgery was excluded.

That attrition rate, from more than four thousand records to just twelve included studies, tells its own story. Despite decades of concern about how surgeons learn their craft, the evidence base for one of medicine’s most technically demanding specialties remains remarkably thin and fragmented. The twelve studies that survived screening came from the United States, the United Kingdom, India, Australia, and sub-Saharan Africa, a geographic spread that the authors note is heavily skewed toward high-income countries. Because the included studies varied so widely in their populations, interventions, and outcome measures, the team chose a narrative synthesis rather than a meta-analysis, meaning they could map the direction and consistency of reported effects but not pool them into a single summary statistic.

One of the clearest signals to emerge concerns case volume. Across the reviewed literature, higher cumulative surgical volume was consistently associated with lower complication rates, reinforcing the long-standing intuition that practice makes safer surgeons. Yet the picture is not purely mechanical. The review found that case-specific risk factors, such as the complexity of an individual patient’s pathology, independently predicted complications even after accounting for trainee experience. In other words, a resident’s hundredth cataract operation on a routine patient may be safer than a supervised first operation on an eye with a traumatized cornea or a weak lens support. This finding carries practical weight: it suggests that training programs should think not only about how many operations a resident performs, but about which operations, matched to the resident’s current level of skill and the level of supervision available.

The review also confronted a question that every surgical patient implicitly asks: is it safe to let a trainee operate? The evidence indicates that surgery performed by residents is associated with higher short-term complication rates compared with surgery performed by experienced surgeons, a result that will surprise no one. More encouraging, however, is the finding that long-term outcomes were often comparable between trainee-performed and consultant-performed procedures. This distinction between immediate and delayed results matters enormously for how training programs and patients think about the learning process. It suggests that the short-term bump in complications associated with supervised trainee surgery may not translate into lasting harm, provided that cases are appropriately selected and supervised and that patients receive adequate follow-up to catch and manage early problems.

Perhaps the most consistent and practically important finding of the entire review involves simulation. Across four studies, including two randomized controlled trials, simulation-based and virtual-reality training was consistently associated with lower complication rates and higher competence scores among trainees. Randomized controlled trials sit at the top of the evidence hierarchy, so their presence in this small literature is notable, and the fact that both pointed in the same direction strengthens confidence in the conclusion. Virtual reality cataract surgery simulators, which allow residents to practice capsule tearing, phacoemulsification, and instrument handling on a computer-generated eye with real-time feedback on tremor and tissue damage, have become increasingly sophisticated over the past two decades. The review’s findings suggest that this technology is not merely a convenient substitute for the operating room but an active driver of safer surgical performance once residents reach real patients.

The authors assessed the methodological quality of the included studies using design-specific tools. Observational studies were appraised with the Joanna Briggs Institute critical appraisal checklists, randomized controlled trials with the Cochrane Risk of Bias 2 tool, and the single instrument validation study with the COSMIN Risk of Bias checklist. Two reviewers independently screened titles, abstracts, and full texts, with disagreements resolved by consensus. This multi-tool approach reflects the heterogeneity of the underlying literature, but it also exposed a deeper problem: most of the evidence rests on observational designs, which are vulnerable to confounding and selection bias. Programs that give residents more cases may also differ in countless other ways from programs that give fewer, making it difficult to isolate the true causal effect of volume alone.

If simulation emerged as the strongest positive finding, the assessment of competency emerged as the weakest link. The review found that validated competency assessment instruments remain strikingly limited, with only one study in the entire evidence base addressing instrument validity in depth. This is a critical gap for a specialty built on microsurgical precision. Without validated tools to measure surgical competence, program directors are left to judge readiness using subjective supervisor impressions, logged case counts, or ad hoc rating scales whose psychometric properties are largely unknown. The authors highlight cataract surgery, the most common operation most ophthalmology residents will perform and the procedure on which much of the global burden of avoidable blindness depends, as an area particularly in need of validated assessment instruments.

The geographic concentration of the evidence adds a further layer of concern. With studies drawn predominantly from the United States, the United Kingdom, India, Australia, and parts of sub-Saharan Africa, the review notes that the evidence base is concentrated in high-income settings, leaving vast regions of the world where cataract surgical backlogs are greatest essentially unstudied in the medical education literature. Training conditions, case mix, supervision ratios, and available technology differ enormously between a well-funded academic center in North America and a district hospital in a low-resource setting. Findings about learning curves and complication thresholds generated in one context may simply not transfer to another, which is why the authors call for more geographically diverse, prospective research.

The overall message of the review is one of cautious optimism paired with a demanding agenda. Simulation-based training and structured, experience-matched case selection are associated with improved surgical outcomes and surgical competence among ophthalmology residents, giving training programs concrete, evidence-supported levers to pull today. At the same time, the field needs prospective studies that follow residents over time, validated assessment tools that can objectively certify competence, and research that extends beyond wealthy countries to the settings where surgical training capacity is most constrained. As virtual reality simulators become cheaper and more widespread, and as regulators and patients increasingly demand objective proof of surgical readiness, the pressure to build a rigorous educational evidence base for eye surgery will only grow. This review provides both a map of what is known and a clear picture of how much work remains.

Subject of Research: Surgical training and competency assessment in ophthalmology residency programs

Article Title: Ophthalmology residency surgical training and competency assessment: a systematic review of medical education evidence

Article References: Krungkraipetch, L., Leelawongs, S., & Krungkraipetch, K. (2026). Ophthalmology residency surgical training and competency assessment: a systematic review of medical education evidence. BMC Medical Education. https://doi.org/10.1186/s12909-026-10546-7

Image Credits: AI Generated

DOI: 10.1186/s12909-026-10546-7

Keywords: ophthalmology residency, surgical education, competency assessment, simulation training, virtual reality, cataract surgery, case volume, learning curve, systematic review, medical education, surgical complications, BMC Medical Education