I have commented elsewhere on some of the challenges of treatment on patients who have already had cataract surgery with artificial lenses: The artificial lenses have a smaller aperture which can sometimes limit my view, and more importantly limit the amount of energy from the laser that can be delivered. Increased difficulty does not equate with increased risk to the eye, it generally will mean that it may be less efficient and require more treatment overall.
My preference is to treat a virgin (no prior surgery) eye with a natural lens with a big, dilated pupil. That is my preference, but I rarely get my preference. Often a patient will inquire as to the preferred order of treatment when they have some cataract changes and floaters.
So let’s start with the basics. A cataract is ANY yellowing, clouding, opacity, or optical irregularity to the crystalline lens of the eye. It is NOT an ‘all or none’ phenomenon. It occurs along a spectrum of involvement and degree. A person may have very mild cataract changes and still have 20/20 or better vision and not even be aware of the lens changes. Another person may have cataracts so advanced that they can not see at all out of the eye.
Cataract surgery involves removing the natural lens and replacing it with a perfectly clear artificial lens. It is one of the most common surgeries performed in the world. Generally, the usually tipping point for the doctors to recommend cataract surgery is when the ‘best corrected’ (best spectacle corrected) vision drops to 20/40 or worse and it is believed due to the cataract.
The laser used to treat eye floaters must pass through the lens to deliver its energy to the eye floaters in the vitreous cavity. The more advanced the cataract, the less organized and less energy can be delivered. Although it was seem a ‘no brainer’ for me to prefer working through an artificial lens (it is perfectly clear AND it eliminated one of the risks of treatment – that of the laser causing a cataract if it is grossly misdirected), the problem with the artificial lenses is that 1. they have a smaller aperture to work through which may limit my view and decrease the delivered energy, and 2. some of the multi-focal lenses intended to give you both near and distance vision will direct my laser’s energy to two focal points in stead on one and also diminish the delivered energy.
I treat patients with natural lenses and artificial lenses. I get whatever walks through the door and I will adapt my technique and effort appropriately. Both groups may benefit from treatment with very acceptable low risk.
So what about when a prospective patient has both floaters and cataract and asks me for my recommendation as to the timing and order of both procedures?
1. If the cataract is mild, that is, best corrected vision is still 20/30 or better, then it may be awhile before cataract surgery will be indicated, and the lens changes are probably mild enough to go ahead and do floater treatment first.
2. If your local doctor is suggesting surgery and vision is now 20/40 or worse (diminished due to cataracts), then go ahead and have your cataract surgery first. Wait a couple months (assuming it is uncomplicated) and then we can treat the floaters.