Treatment of vitreous strands and opacities (ocular floaters)
What is Degenerative Vitreous Syndrome and what causes floaters?
The vitreous humor is the clear, jelly-like substance in the main chamber of the eye, located between the lens and the retina. At a young age, the vitreous is transparent. As the eye ages, the vitreous humor normally degenerates, losing its clear form and developing strands and clumps of protein and pockets of fluid. These fibers and bits of protein cast shadows on the retina and thus appear as moving spots, strings, or cobwebs. Slow changes in floaters are generally not a warning sign of eye disease but can be quite annoying visually. Some patients develop a sudden shift in the vitreous gel that can cause flashing lights in the side vision and an abrupt onset of many floaters. In these abrupt cases, the eye should be examined with dilation within a day or two in order to rule out any retinal damage (tears or detachments) from the shifting vitreous. It is not appropriate to treat sudden onset floaters with laser until 3-4 months have passed, and the retina health in these cases is the critical issue.
What is vitreolysis?
Also known as floater laser treatment, vitreolysis is a pain-free procedure that can significantly reduce the visual disturbances caused by floaters. The goal of vitreolysis is to achieve a “functional improvement”, that is, to allow patients to return to “normal” day-to-day activities without the hindrance and distraction of persistent floaters. Many types of floaters can be successfully treated but some can not, so a clinical evaluation is performed at an initial visit to ensure that laser application is a reasonable therapy. The doctor and patient then agree on which areas of floaters are causing problems and treatment is directed at these areas.
How does vitreolysis work?
Vitreolysis involves the application of very well focused nanosecond pulses of laser light to actually evaporate the vitreous opacities and to sever the vitreous strands. During this process, the floatercollagen and protein molecules are converted into a gas, which is then absorbed by the eye. The end result is that the floater is removed and/or reduced to a size that no longer impedes vision.
What happens during the procedure?
Vitreolysis is performed as an office procedure The eye is well dilated, and then an anesthetic drop is applied to to eye to keep it comfortable.A contact lens is then be placed on the eye, with the laser light delivered through a specially designed microscope and focused directly on the floater areas.
During treatment, patients may observe small, dark specks orshadows, some dim light pulses, and a bright colored light (aiming light). Some patients hear a little clicking but there are no bright flashes from the laser and typically no sensations other than the contact lens being in position for therapy. The vitreous has no nerve fibers so cannot “feel” the treatment itself.
Once the treatment is complete, you may return to normal activities and use the eye normally. A follow-up visit to re-examine the dilated eye and reassess for floaters is typically scheduled for 4-6 weeks after initial therapy.
Each treatment session typically takes 5-10 minutes to perform and some patients will need to undergo a second or third treatment in order to obtain the best results. Such repeat treatments are generally spaced 4-6 weeks apart, in order to allow the laser to reach its final effect.
What can I expect after treatment?
You may observe small, dark specks in your lower field of vision immediately following treatment, but these small gas bubbles will quickly dissolve. It is also important to note that some patients may experience mild discomfort, redness or temporarily blurred vision directly following treatment, these generally being due to dilation of the eye and a gel that is used to keep the contact lens in position.
Complications and side effects
Reported side effects and complications associated with vitreolysis are rare. Side effects may include cataract formation and intraocular pressure (IOP) spike. Sometimes the contact lens may cause short-term surface irritation. Bleeding and infections have not been reported from this therapy.
Who will benefit from vitreolysis?
It is necessary to undergo an initial ophthalmic examination in order to determine your eligibility for vitreolysis treatment.
- Age: In most cases, younger patients (<45) suffer from microscopic floaters located close to the retina and are not considered to be good candidates for vitreolysis treatment.
- Onset of Symptoms: If your floater symptoms develop very quickly then they may be associated with a posterior vitreal detachment “PVD”, and in these cases, it is important to evaluate the retina for any damage caused by the PVD. Typically floaters from a PVD improve on their own, so generally, 3-4 months should pass before vitreolysis is used in these cases.
- Floater Characteristics: Well defined floaters with a soft border are ideally suited to treatment with vitreolysis, although more diffuse strands of floaters and “wavy” material may also be treated. Certain types of floaters are not treatable, so it is important to examine the eye before laser treatment is scheduled.
- Typically, one eye at a time is treated, the most bothersome one receiving the initial therapy.
What if vitreolysis doesn’t work for me?
Clinical studies have shown vitreolysis to be a safe and effective treatment in the majority of patients. If floaters persist after laser therapy, or in cases where it is unlikely that laser therapy will be of any benefit, your ophthalmologist may recommend a surgical option called “vitrectomy”. A vitrectomy is performed by a retinal specialist in an operating room where the surgeon uses small tools to remove part or all of the vitreous gel, replacing it with a special saline solution. The details of vitrectomy surgery are beyond the scope of this section but have been the only treatment for floaters up until recently.