Today cataract is readily treatable with modern surgery, and while the surgery has evolved over time, far more progress has been made in the last fifty years than in the preceding two thousand.
The surgery has evolved from intra-capsular cataract surgery where the whole lens was removed, to extra-capsular where the capsule remains in order to support an intraocular lens. This better technology has seen significant improvements in visual outcome and most importantly, safety. Routine suturing of surgical wounds has become a thing of the past by performing the surgery with phacoemulsification through a 3 mm or less wound, followed by the implantation of a foldable intraocular lens.
In the last decade we have seen similar advances in laser technology. Lasers of varying wavelengths are used in medical practice, and design has been adapted for use in the eye. There is now an argon laser for retinal disease, and the YAG laser for posterior capsular thickening and iridotomies. The excimer laser has been developed for corneal refractive surgery and SLT laser for glaucoma.
The advantages of the femtosecond laser for laser vision correction were initially seen as minimal (less likelihood of a hole or tear in a flap, a more precise depth of cut and a lessened risk of epithelial ingrowth) because complications were already rare and the new technology was expensive. However, with the improved safety and flap quality ensured today, nearly all refractive laser surgeons use the femtosecond laser to create LASIK flaps.
It is this femtosecond laser technology that has now been adapted for cataract surgery in the Laser Cataract operation.
Is this new technology worth adopting? Can the increased expense be justified, and finally does it represent a significant improvement in precision and safety?
Ophthalmologists by nature are cautious and averse to changes in their operating habits. This was apparent when we moved to phacoemulsification and smaller incisions, followed by intraocular lens implantation.
Currently Laser Cataract surgery (LCS) has a relatively short clinical history with the majority of the 30,000 procedures to date having been undertaken in the last year. While there are other femtosecond cataract lasers entering the market, most of these cases have been performed with the LenSx. Considerable data has been gathered to date and the learning curve shortened.
The first cataract laser in Australia was installed at Vision Eye Institute (VEI) in Sydney in April 2011. Significantly the centre now has the largest published series of laser cataract cases in the world.
How is Laser Cataract Surgery different?
- The laser replaces the hand held blades used for the corneal incisions. Unlike a blade the laser can be programmed to make a precise cut with a shape not otherwise achievable mechanically. The shape, length and width can all be programmed with the laser. The quality of the corneal wound produced reduces the incidence of surgically induced astigmatism, reduces risk of wound leakage and, theoretically, infection.
- The opening of the anterior capsule (capsulorhexis) allows access for removal of the previously laser divided nucleus and cortex. Centration of the capsulorhexis can be aligned with the visual axis due to the precision of the laser which leads to more accurate placement of the intraocular lens, and this has been shown to provide better refractive outcomes. The perfect circularity of the laser capsulorhexis contributes to an effective lens position not able to be achieved manually.
- Finally, by dividing the nucleus with the femtosecond laser, it allows for reduced phacoemulsification ultrasound energy. The risk of posterior capsule rupture is minimal with this laser. Another advantage of less energy is that damage to corneal endothelial cells is greatly reduced.
Are there any problems associated with the laser?
- The new technology utilises a Patient Interface (PI). This is a single use item and at present there is no rebate from Medicare or the Health funds.
- Normally the laser is situated in a separate room so the cataract procedure is undertaken in two steps (similar to LASIK).
- As the Patient Interface is a suction device there is a higher likelihood of a transient subconjunctival haemorrhage. This is of no clinical significance.
Is everyone suitable?
No, there are certain eyes that are not suitable; for example those with smaller pupils or with a lens that is tilted, or if there are significant corneal opacities which the laser is unable to penetrate. However the laser excels in previously high risk situations when done mechanically. For example, if the patient has a white mature cataract, pseudo exfoliation, dense cataract, the ability to perform the initial part of the procedure with the laser is extremely beneficial.
Current manual cataract surgery will still be an acceptable alternative for those patients not suitable or for those surgeons without access to the Cataract Laser. But as our experience grows and more of the published data confirms the apparent benefits it will be clear that LCS is a significantly safer and more precise procedure.
Finally, it is with great excitement that the surgeons Drs Lewis Levitz and Joe Reich who consult at VEI Camberwell, VEI Blackburn South and Coburg, together with Dr Abi Tenen at VEI Blackburn South, VEI Coburg and VEI St Kilda Rd and Dr Raj Pathmaraj at VEI Blackburn South now have this technology available for their patients.