IOL Injectors and Cartridges for Residents: Alcon A, B, C, D, Preloaded Systems, J&J Unfolder, Zeiss, Medicel and Indian Lenses
Last updated: November 2026
The cartridge decides how small your incision can be, whether the lens unfolds safely, and whether the wound stays watertight. Every company has its own injector and cartridge system, and each lens is approved for particular cartridges. This guide explains the parts, the Alcon A to D cartridges, preloaded and automated injectors, J&J, Zeiss and Medicel systems, the injectors supplied with Indian lenses, how to load, and what to do when things go wrong.
The parts of an injector system
| Part | What it does | Notes |
|---|---|---|
| Injector (handpiece) | Pushes the lens through the cartridge | Reusable metal (screw or push type, autoclaved) or single-use plastic |
| Cartridge | Folds the lens and delivers it through its tip | Loading chamber with wings, a tapered tube and a bevelled nozzle; single use |
| Plunger tip | Contacts the lens | Soft silicone tips cushion the optic; a misaligned plunger can override or crush the optic |
| Preloaded injector | Lens is loaded in the factory | No handling of the lens; less risk of loading errors and contamination; fixed cartridge size |
| Automated injector | Motor or gas pushes the lens at a set speed | e.g. Alcon AutonoMe; smooth, controlled delivery |
Tip position matters. The incision size printed for a cartridge usually assumes the tip goes into the wound. With a wound-assisted technique, the tip rests just at the wound lip and the lens is pushed through the tunnel, allowing a smaller incision, but it stretches the wound more and needs a well-formed tunnel.
Alcon Monarch cartridges: A, B, C and D
The letters describe tip size, from largest (A) to smallest (D). Monarch handpieces are reusable; cartridges are single use. Each AcrySof or Clareon lens's directions for use list the cartridges and power ranges it is qualified for, so check the box insert before you choose.
| Cartridge | Tip | Used for | Typical incision |
|---|---|---|---|
| A | Largest | Older large three-piece lenses; rarely used now | Larger than 3 mm |
| B | "Big" | Three-piece acrylic IOLs (e.g. for the sulcus) and special-order high plus single-piece lenses; has a peg that holds the trailing haptic | About 3.0 mm |
| C | "Compact" | Single-piece AcrySof lenses, including higher powers; three-piece lenses with a special loading method (trailing haptic left outside the tip) | About 2.6–2.75 mm |
| D | "Diminutive" | Most single-piece AcrySof lenses in the usual power range; works best with thinner aspheric designs | About 2.2–2.4 mm |
- Handpieces: Monarch II takes A, B and C cartridges; Monarch III takes C and D; Monarch IV is designed for the D cartridge. Do not mix a cartridge with a handpiece it is not made for.
- Preloaded: UltraSert is Alcon's manual preloaded injector; AutonoMe is an automated, gas-powered preloaded injector. In laboratory and clinical comparisons at 2.2 mm, the automated injector stretched the incision slightly less than manual preloaded injectors, though wound healing was similar by one month.
- Three-piece in the C cartridge: possible through an unenlarged incision, but the leading haptic can twist; straighten it with a second instrument before injecting.
Johnson & Johnson (TECNIS) systems
| System | Lenses | Incision | Notes |
|---|---|---|---|
| UNFOLDER Platinum 1 Series (handpiece DK7796 with cartridge 1MTEC30) | TECNIS acrylic single-piece IOLs, into the capsular bag only | 2.2–2.4 mm | Rear-loading cartridge; screw-style delivery |
| UNFOLDER Emerald XL | TECNIS single-piece and three-piece lenses | 2.8 mm | Single-use cartridge |
| Preloaded: TECNIS Simplicity and iTec | TECNIS single-piece lenses | About 2.2–2.4 mm | No loading; iTec stretched the wound slightly more than AutonoMe or UltraSert in one laboratory test |
From the Platinum 1 Series instructions: fill the whole cartridge with viscoelastic (J&J recommends its HEALON family; not balanced salt solution, and not methylcellulose OVDs); grasp the lens only by the optic edge, anterior side up; tuck the leading haptic, then the trailing haptic over the optic; discard if the lens has been folded in the cartridge for more than 5 minutes; inject high powers more slowly in a cold theatre; store cartridges between 5 and 30°C.
Zeiss, Medicel, Hoya and others
| System | Type | Incision | Notes |
|---|---|---|---|
| Zeiss BLUEMIXS 180 | Preloaded | 1.8 mm | For Zeiss micro-incision hydrophilic lenses (e.g. AT LISA tri, CT ASPHINA MP models) |
| Zeiss AT.Shooter A1-2000 | Reusable injector | 1.8 or 2.2 mm | With AT.Smart or VISCOJECT-BIO cartridges |
| Medicel VISCOJECT-BIO | Single-use injector set | 1.8 or 2.2 mm | Used for many hydrophilic lenses |
| Medicel ACCUJECT | Single-use injector with built-in cartridge | Varies by model | Supplied with many lenses from different companies; load OVD first, notched haptics at 1 and 7 o'clock, wait for the click-lock |
| Hoya iSert | Preloaded | About 2.2 mm (model dependent) | e.g. Vivinex iSert |
Indian lenses and their injectors
- Most Indian foldable lenses come with a single-use plastic injector and cartridge in the box or as a matched set, often labelled by incision size (commonly 2.2 or 2.8 mm).
- Aurolab: Auroflex hydrophilic lenses are supplied with an injectable cartridge and injector; the Aurovue EV hydrophobic lens is available preloaded for a 2.8 mm incision (5 to 35 D).
- Appasamy: Acryfold hydrophilic single-piece lenses come with a disposable injector and cartridge system.
- Many companies supply lenses with Medicel ACCUJECT-type injectors; others use their own designs.
- Hydrophilic lenses fold more easily and often pass through smaller cartridges; hydrophobic lenses are stiffer and usually need a slightly larger cartridge or slower injection.
- Always use the injector and cartridge recommended for that lens. A cartridge that "fits" a different brand may still crack, scratch the optic or trap a haptic.
Choosing a cartridge
| Situation | Usual choice |
|---|---|
| Single-piece hydrophobic lens, usual power | The smallest qualified cartridge (e.g. Alcon D, J&J Platinum 1) |
| High-power single-piece lens (thick optic) | A larger cartridge (e.g. Alcon C) or the power limit in the lens insert |
| Three-piece lens for the sulcus or a capsular complication | Alcon B (or C with special loading), J&J Emerald, or the matched three-piece cartridge |
| Hydrophilic micro-incision lens | The 1.8 or 2.2 mm cartridge listed for that lens |
| Toric or multifocal premium lens | Preloaded injector if available, to avoid loading damage; check the insert |
| Cold theatre or stiff lens material | Warm the lens to room temperature and inject slowly |
How to load a manual cartridge
Step by step
- Check the lens model, power and expiry, and the cartridge and handpiece match the insert.
- Fill the cartridge loading chamber and tube with the recommended viscoelastic. Never load dry or with balanced salt solution only.
- Hold the lens by the optic edge with smooth forceps, anterior side up. Do not grasp the trailing haptic.
- Place the leading haptic into the tip direction and the trailing haptic as the cartridge diagram shows (folded over the optic for single-piece lenses; outside or on the peg for three-piece lenses).
- Close the wings slowly and evenly; look from the side to check no haptic or optic edge is caught.
- Insert the cartridge into the handpiece until it clicks; advance the plunger until the lens is just inside the tip. Check the plunger is behind the optic, not riding over it.
- Inject soon after loading (J&J: within 5 minutes), with the bevel facing down for most single-piece lenses so the leading haptic stays in the bag; follow the lens insert.
- Advance slowly and steadily; slow down as the optic exits so the lens unfolds gently in the bag.
Problems and what to do
| Problem | Cause | Prevention or rescue |
|---|---|---|
| Cartridge tip cracks or splits | Wrong cartridge for the power, cold lens, too little OVD, injecting too fast | Stop; remove the cartridge; reload a new lens and cartridge; use a larger cartridge |
| Trailing haptic broken or crushed | Haptic caught by the plunger or wings | Load carefully; check from the side before injecting; replace the lens if damaged |
| Lens comes out upside down | Loaded posterior side up, or cartridge rotated | Check orientation marks before injecting; flip in the bag only with care |
| Plunger overrides the optic | Misaligned plunger, too little OVD | Check plunger position after advancing; withdraw and reload |
| Lens shoots out uncontrolled | Pushing hard against resistance, then sudden release | Inject smoothly; reduce speed as the optic exits |
| Wound stretch, leak or tear | Tip too large for the incision, wound-assisted push in a short tunnel | Choose the right cartridge; check the wound; suture if it leaks |
| Descemet membrane detachment | Tip entered under Descemet membrane | Keep the bevel in the plane of the tunnel; recognise early and tamponade with air if needed |
| Optic scratches or marks | Forceps damage, dry cartridge, wrong cartridge | Use smooth forceps, enough OVD and the matched cartridge |
Pearls
- Read the lens insert for the qualified cartridge and power range; the box is the authority, not habit.
- Look at the loaded lens from the side before injecting: most haptic and plunger problems are visible.
- If you feel unusual resistance, stop: forcing a jammed lens cracks the cartridge or damages the lens.
Common mistakes
- Using a D-sized cartridge for a very high power lens and cracking the tip.
- Loading the trailing haptic where the plunger can catch it.
- Leaving the lens folded in the cartridge while you finish other steps.
Test yourself: flip cards
Quick quiz
Related: IOL Lens Types Explained: Monofocal to Trifocal, Toric IOL Pearls: Rotation, Posterior Corneal Astigmatism and Marking, Sulcus IOL Power Adjustment: How Much to Reduce and When Not To, Posterior Capsule Opacification, Nd:YAG Capsulotomy and IOL Dislocation, Cataract Pre-operative Risk Checklist: Spot the Difficult Case.
Key sources
- Johnson & Johnson Vision. UNFOLDER Platinum 1 Series implantation system: directions for use; UNFOLDER delivery systems product page
- US FDA 510(k) K063155: Alcon Monarch III cartridge D (2006)
- Cataract Coach (Uday Devgan). IOL cartridges: which one? (2020); Three-piece IOL: B versus C cartridge (2020)
- Zeiss Meditec. Injector portfolio and IOL correlation chart
- BVI Medical. Medicel ACCUJECT injector guidelines (2024)
- EuroTimes (ESCRS). Automatic IOL inserters
- IAPB Valued Supplier Scheme product listings: Aurovue EV preloaded, Auroflex, Acryfold
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