Endocyclophotocoagulation (ECP) is a form of eye laser surgery developed in 1992, performed to lower intraocular pressure (IOP) so as to control glaucoma and reduce reliance on eye drop medicine. ECP can be done by itself or in conjunction with other micro-invasive glaucoma surgeries such as cataract surgery or aqueous shunt insertion.

Glaucoma is a progressive eye disease that destroys the optic nerve and is caused by higher than normal IOP. Globally, the disorder is one of the leading causes of preventable blindness. Eye drops typically manage this condition, but in some instances, surgery is required.

This procedure lowers the amount of aqueous humour produced, by targeting and destroying the ciliary body processes (the structure responsible for aqueous humor creation). The aqueous humor is a clear fluid found in the eye and responsible for providing nutrition to the eye’s tissues. When there is a blockage in any of the eye’s passages, there is aqueous humor build-up, leading to high IOP. High IOP can also arise from more fluid being produced than is being drained. 

ECP is one of the three forms of cyclophotocoagulation (CPC). When compared to other forms of CPC such as transscleral cyclophotocoagulation (TCP), it is considered more superior because it is associated with far fewer risks.

ECP uses a miniature endoscope inserted via a small incision, allowing visualization of the problematic area.

Also Known As

  • Endoscopic cyclophotocoagulation


Preparation & Expectation Before Surgery

For a week before the procedure, the patient is asked to avoid taking medications such as aspirin, arthritis medication, and blood thinners. Diabetes patients will be advised on how to administer their insulin. In some cases, patients are required to fast for six hours prior to the surgery. 

Before the surgery begins, the eye specialist will give the patient liability forms to consent to.

Although the surgery involves a slit being made, it is a safe, minimally invasive procedure and takes only a few minutes to perform. The patient is allowed to leave after the procedure but is required to have someone drive them home because an intracameral anesthetic drop is placed on the eye.

Types, Purpose & Procedure

ECP is an ideal treatment for patients who need to lower their IOP significantly. It is also conducted to help patients who are hoping to reduce or eliminate the use of their topical ocular hypotensive medications. It is also helpful for patients suffering from more advanced types of glaucoma, where there have been instances of previously failed surgery. The surgery is not suitable for advanced glaucoma as it does not reverse vision loss.

The procedure is suitable for patients with excellent vision or those who have never had cataract surgery, because it increases the chances of developing cataracts.

This laser treatment is often done after the completion of cataract surgery. The pupil is dilated and a viscoelastic agent expands the ciliary sulcus. The surgeon intraocularly inserts an endoscope through the same cataract/limbal incision. The endoscope has a lens, a light source and a fiber optic cable, which helps the surgeon view and magnify the ciliary processes on a video monitor.

A 20 gauge gives a 70° field of view, while the 18 gauge provides a 110° view. The doctor can control variables such as beam intensity, power, and lighting, using console controls while a foot pedal controls laser firing.

S/he then observes the eye’s internal structure and targets the laser energy to the ciliary processes. This surgery takes 10-20 minutes to complete.

Risks, Side Effects & Complications

Inflammation of the eye, light sensitivity and excessive pain are the most common side effects noted after the procedure. Inflammation is easily treated with topical steroid use while light sensitivity often goes away after a few weeks.

Complications that may arise from ECP include:

  • IOP elevation
  • Permanent decrease in vision or loss of vision
  • Chronic hypotony (low intraocular pressure)
  • Hyphema (bleeding in the eye) - This risk is seen in about 12% of patients who undergo ECP.
  • Macular edema (retinal swelling) - This is easily treated with prescribed eye drops. However, without treatment, this complication can lead to vision loss.
  • Choroidal detachment - This can also be treated with prescribed eye drops, but surgery is needed in more severe cases.


After Care, Recovery & Outcome

After the procedure, the patient is required to wear an eye patch for 24 hours. They are also required to go back to the eye specialist’s office the following day, where the eye patch will be removed and the IOP will be checked.

For the next four to six weeks, the patient will use prescribed postoperative drops. It takes one to eight weeks for the outcome to be known. Once the surgery’s success is determined, the eye doctor will advise whether the patient will continue or modify the amount of glaucoma eye drops they are using.

ECP does not guarantee permanent low aqueous fluid production as the ciliary body can regenerate. In this case, repeat surgery is recommended.