Never Go In Blind

A novel and realistic ophthalmic block simulator has been shown effective in helping trainees gain confidence and competence performing blocks in a safe environment, reported Elizabeth Wen Ling Lim MD. Although commonly performed, poorly conducted ophthalmic regional blocks could increase the risk of intraoperative complications, longer operative time, and therefore poor outcomes.

According to Dr Lim, trainees in Singapore undergo minimal training before attempting their first ophthalmic block on a patient in the operating theatre—a procedure that grants little to no visualisation of the target tissues—essentially going in blind.

“There are some potentially blinding complications while performing a peribulbar block, including the most feared—perforation of the globe and retrobulbar haemorrhage,” she said. “And the risk factors increase when an inexperienced student makes multiple attempts.”

With her colleagues at the Singapore National Eye Centre and Singapore Eye Research Institute, Dr Lim developed a model to target this issue and respond to a large unmet need in ophthalmic surgery. She described the model as a multipurpose and realistic ophthalmic block simulator. This device can incorporate sham eyes of different axial lengths to better simulate even cases of high myopia, which is notably a high-risk factor for globe perforation.

Moreover, the simulation features a 3D-printed bony orbit modelled after actual CT orbit dimensions made of long-lasting and non-biodegradable materials. Its transparent properties allow direct real-time visualisation of needle positioning, making it the first model in literature able to simulate the conjunctiva. The model is portable, and every part can be replaced individually instead of changing the whole device.

Dr Lim noted this model also allows for the practice of multiple types of blocks on the same model, such as infra-orbital, sub-tenons, and supraorbital blocks. To better study model efficacy, a pilot study was performed at the Singapore National Eye Centre to engage residents and consultants in providing feedback before and after using the simulation for training purposes.

Both confidence and competence were higher post-workshop compared to pre-workshop. Residents felt there was improved akinesia after performing blocks in the operating theatre, and while it was not statistically relevant, residents’ competence also improved, Dr Lim reported. No penetrating injuries on patients were reported in the training group after the workshop.

“With no simulators commercially available at present, our ophthalmic block simulator meets a large unmet need. This simulator is realistic, life-like, modifiable, versatile, long-lasting, and especially effective in helping ophthalmic trainees gain confidence and competence in performing blocks in a safe environment,” she concluded.

Dr Lim presented at the 2025 ESCRS Winter Meeting in Athens.

Elizabeth Wen Ling Lim MD is a resident of the Singapore National Eye Centre and Singapore Eye Research Institute of Singapore. limelizabeth@gmail.com