3D Display Systems in Ophthalmic Surgery

Key Points at a Glance

1. What is a 3D display system in ophthalmic surgery?

A 3D display system for ophthalmic surgery is a new surgical visualization technology that replaces the traditional binocular microscope. Instead of looking through eyepieces, the surgeon operates while observing real-time images captured by a 3D camera on a large monitor. This surgical style is called “heads-up surgery.”

Background and development history

3D display technology was initially developed for aviation and military use. Later, technological innovations enabled its introduction into operating rooms. In ophthalmology, it became widely adopted after the introduction of the TrueVision 3D visualization system for microsurgery.

In traditional microsurgery, surgeons had to maintain a forward-leaning posture for long periods, causing strain on the cervical spine, back, and waist. It has been reported that the prevalence of neck, upper body, and waist symptoms among ophthalmologists reaches 62%. The 3D system was developed to address this issue.

Active and Passive Systems

Active systems

Mechanism: Rapidly alternating sequential images displayed for left and right eyes

Glasses: Electronically controlled shutter glasses actively block one eye at a time

Features: High stereoscopic effect. Crosstalk (ghosting) may occur

Passive systems

Mechanism: Two images are mixed horizontally for output

Glasses: Passively separated by polarized 3D glasses

Features: Lower cost. Used in NGENUITY, etc. No crosstalk

Q What is heads-up surgery?

This is a surgical method performed by viewing images captured by a 3D camera on a large display, without looking through the microscope eyepieces. The surgeon can operate in a natural heads-up posture, significantly reducing strain on the cervical spine and lower back. Since multiple staff members can share the same image in real time, this system also offers high educational benefits.

2. Main Systems and Functions

TrueVision 3D System (TrueVision Systems Inc., Santa Barbara, CA, USA)

Heads-up cataract surgery in ophthalmology was first reported by Weinstock in 2010. The TrueVision 3D System is a camera unit attached to a standard surgical microscope, transmitting stereo images and video to a 3D HD large-screen monitor.

The US FDA has approved the “TrueVision Refractive Cataract Toolset” which provides 3D graphical overlays. Furthermore, the “TrueGuide” and “TruePlan” applications enable support for surgical planning, including the use of toric IOLs.

Applications in anterior segment surgery are also expanding. Heads-up systems are used in amniotic membrane transplantation and corneal surgery. Mohamed YH et al. reported the first case of corneal surgery (non-Descemet stripping automated endothelial keratoplasty: nDSAEK) using a heads-up system.

NGENUITY® 3D Visualization System (Alcon, TX, USA)

The NGENUITY® is the world’s first real-time ophthalmic imaging system equipped with a High Dynamic Range (HDR) video camera. It is widely used in all types of ophthalmic surgery, including strabismus surgery, cataract surgery, glaucoma surgery, and vitreoretinal surgery.

Item	Specification
Display	55-inch 4K Ultra HD OLED
3D glasses	Passive circular polarized glasses
Image processing	HDR (High Dynamic Range)

HDR technology ensures bright visibility without overexposure, enabling safe surgery with deep depth of focus. It reproduces images comparable to the naked eye even to the peripheral retina, and can highlight proliferative membranes using digital filter functions.

Main advantages:

Surgical time and complication rates are comparable to those of conventional microscopes
Reduces the output of the endoilluminator, decreasing phototoxicity
Easy to use even in patients with special body types such as severe kyphosis
Reduces the need for triamcinolone staining of the vitreous
Preoperative information and optical coherence tomography (OCT) images can be overlaid in real time.
High satisfaction scores among surgeons and nurses.

Reported limitations:

Logistical difficulties and cost.
Discomfort for assistants.
Difficulty responding to sudden head movements by the patient.
Reduced visibility in the presence of media opacities

Q What technology is NGENUITY®'s "HDR"?

High Dynamic Range (HDR) is an imaging technology that can simultaneously and appropriately represent both overly bright and overly dark areas. It can reproduce images similar to the naked eye, even in the peripheral retina where conventional surgical microscopes tend to cause whiteout. Additionally, because it allows for reduced light intensity, it helps reduce phototoxicity to the retina during long surgeries.

Other heads-up 3D visualization systems

The main systems used in ophthalmology are shown below.

Sony HD Medical Display system (Sony, Tokyo, Japan)
MKC 700 HD and CFA 3DL1 (Ikegami Tsushinki, Tokyo, Japan)
Artevo 800 (Zeiss, Germany)
Panoramic RUV viewing system (Leica, Wetzlar, Germany): for vitreoretinal surgery

3. Application to Vitreoretinal Surgery

Heads-up surgery in the retinal field was introduced by Eckardt and Paulo. Studies evaluating heads-up vitreoretinal surgery using a 3D HDR camera and HD LCD display have found the following:

The main advantage is superior ergonomics.
Technical difficulty is equivalent to conventional methods
Electronic amplification of the camera signal achieves higher brightness than conventional methods
Advantageous in cases such as vitreous hemorrhage, media opacities, and darkly pigmented fundi

Combined with intraoperative OCT, it enables confirmation of the presence of macular holes and the status of internal limiting membrane (ILM) peeling. It is also effective for verifying the procedure during the inverted ILM flap technique. In corneal surgeries such as DMEK (Descemet membrane endothelial keratoplasty) and DSAEK, it is considered useful for confirming the positioning of the donor graft.

Recent reports from a systematic review comparing macular hole surgery using conventional microscopes and 3D visualization systems like NGENUITY® showed that the 3D system reduces light exposure to the retina and improves surgeon comfort.

4. Head-mounted system (HMS)

Head-mounted systems (HMS) use a display worn on the surgeon’s head instead of a large monitor. This is gaining attention as an emerging concept in ophthalmology.

Heads-Up System (Large Monitor)

Viewing method: Large monitor shared by the entire room

3D glasses: Observe while wearing polarized glasses

Educational effect: Multiple people can view the same image simultaneously

Head-Mounted System (HMD)

Viewing method: A display worn on the surgeon’s head

Independent display: Simultaneous display of independent images to the left and right eyes

Crosstalk: Avoids ghosting phenomena in active shutter systems

Sony HMS-3000MT

Sony is a pioneer in head-mounted displays and first entered the operating room in 2012. The HMS-3000MT is used in combination with Haag-Streit Surgical’s microscope (HS Hi-R NEO 900).

System configuration:

HMI-3000MT: Image processing unit
HMM-3000MT Head Mounted Display: Provides stereoscopic vision
MCC-3000 MT: 3D full HD surgical camera system

The resolution is 1280×720 stereoscopic images, and dual video input using two independent OLED panels provides completely independent signals to each eye. A wide horizontal viewing angle of 45 degrees enables a natural visual experience.

Historical background of HMS

Early experiments by Ivan Sutherland in the 1960s led to the development of HMS. The main applications of HMS were military, police, firefighting, and civilian commercial use (video games, sports, etc.). The use of HMS in ophthalmology was first reported by the group of Dutra-Medeiros et al.

Examples of HMS-adapted surgical procedures (reported by Dutra-Medeiros et al.)

Pars plana vitrectomy (alone or combined with phacoemulsification + IOL implantation)
Subluxated IOL extraction
Epiretinal membrane peeling
Internal limiting membrane peeling
Endolaser photocoagulation
Tamponade with silicone oil or sulfur hexafluoride gas

Q What are the advantages of the head-mounted system?

The head-mounted system (HMS) displays independent images to each eye simultaneously, avoiding the ghosting (crosstalk) that occurs with active 3D systems. With a wide 45-degree horizontal field of view, it provides a natural visual experience, enabling excellent depth perception and spatial awareness. Additionally, connecting a second HMD allows surgical staff to view stereoscopic images simultaneously, making it a promising tool for surgical education.

5. Application and adaptation to standard treatment

Overview of applicable surgical procedures

Surgery type	Main system	Remarks
Cataract surgery	NGENUITY, TrueVision	Compatible with IOL guidance
Vitreoretinal surgery	NGENUITY, Artevo	Phototoxicity reduction effect
Corneal surgery (DMEK/DSAEK)	Heads-up type general	Useful for graft position confirmation
Strabismus surgery	NGENUITY	Shared by multiple staff
Glaucoma surgery	Heads-up type general	Visualization of shunt placement

Image Enhancement Features

The latest systems incorporate the following functions through digital image processing.

Color channels: Improved visualization of fine tissues such as the internal limiting membrane (ILM)
Digital filters: Enhanced display of proliferative membranes
Overlay function: Real-time superimposition of preoperative planning information and OCT images
Electronic zoom: Brightness enhancement by amplifying camera signals (improved visibility in cloudy fundus)

6. Pathophysiology and detailed pathogenesis

Ergonomic problems of conventional microscopes

In conventional ophthalmic surgery using a binocular microscope, the surgeon must maintain a forward-leaning posture to look through the eyepieces. This causes chronic strain on the cervical, thoracic, and lumbar spine. It is reported that 62% of ophthalmologists experience symptoms related to the neck, upper body, and lower back, and musculoskeletal disorders have been a factor shortening surgeons’ careers.

Principle of Stereopsis

Depth perception in 3D display systems requires that the left and right eyes receive different images.

In the active shutter method, electronic shutters switch rapidly to separate images for the left and right eyes, but crosstalk (ghosting) can occur due to afterimages. The passive method uses polarizing filters for separation, resulting in less crosstalk. In HMS, two independent OLED panels are used to provide completely independent signals to each eye, eliminating crosstalk.

Significance of Digital Image Processing

By digitally processing images captured by a camera, information that is not directly visible to the human eye can be visualized. HDR technology renders details even in surgical fields with high contrast, and digital filters enhance the identification of specific tissues. Electronic brightness amplification allows for high visibility while reducing light intensity (reducing phototoxicity).

7. Latest Research and Future Prospects

In the field of ophthalmology, 3D display systems are expected to continue evolving with further technological innovations.

Resolution Improvement: The issue of insufficient 2K resolution is being resolved with the evolution to 4K and 8K. In the future, structures that were previously invisible to the human eye under conventional optical microscopes may become visible.

AI Integration: Integration with real-time image analysis, intraoperative navigation, and surgical planning support is expected to advance. Applications such as TrueGuide and TruePlan are already pioneering this.

Development of HMS: New head-mounted systems (such as the Avegant Glyph retinal projection system and Beyeonics Surgical Clarity™) have emerged, and further miniaturization and weight reduction are anticipated.

Expansion of Educational and Collaborative Uses: Applications in live surgery streaming and remote surgical training are being considered. The ability for multiple staff members to simultaneously view in 3D holds potential as a next-generation surgical education tool.

8. References

National Institute for Health and Care Excellence (NICE). Clinical guideline on idiopathic full-thickness macular holes. DRAFT; 2024.
Muecke TP, Casson RJ. Three-Dimensional Heads-up Display in Cataract Surgery: A Review. Asia Pac J Ophthalmol (Phila). 2022;11(6):549-553. PMID: 36417680.
Razavi P, Cakir B, Baldwin G, D’Amico DJ, Miller JB. Heads-Up Three-Dimensional Viewing Systems in Vitreoretinal Surgery: An Updated Perspective. Clin Ophthalmol. 2023;17:2539-2552. PMID: 37662647.