Daniel Driscoll, M.D.
Contributing Editor
Case presentation
Background:
A sixty year old female presented to the eye emergency department with a history of poorly controlled diabetes, hypertension, and hypercholesterolemia. Subsequent workup yielded bilateral neovascular glaucoma with pressures greater than forty in both eyes and vision less than 20/200 in both eyes. The patient underwent emergency pan-retinal photocoagulation in both eyes and was placed on maximal medical therapy consisting of topical timolol 0.5% BID OU, brimonidine 0.2% OU TID, dorzolamide 2% OU BID, and latanoprost 0.005% OU QHS. Additionally, she was given methazolamide 50 mg PO BID. Her response in the right eye was poor to maximal therapy, and she underwent subsequent Baerveldt glaucoma drainage implant with resolution of her high pressures to the mid-teens at follow-up. The patient’s left eye responded well to the maximal therapy, and she was continued on this regimen in her left eye indefinitely, maintaining pressures in the low 20’s to high teens at weekly follow up. Eventually, the patient was lost to follow up for approximately three months due to difficulties with transportation.
Present day:
The patient presented again to the emergency department with painful red eye OS with visual acuity of 20/200 and pressure by applanation of 45. Her right eye was the same visual acuity, pressure, and overall condition as it had been after her surgery approximately three months prior. The patient admitted to poor compliance with her medical drops and oral therapy, stating she ran out of her medicines about one month ago and didn’t have anyone to help her get them refilled. She underwent hourly application of the aforementioned four topical drops in addition to oral Isosorbide and was able to be discharged after five hours with IOP of 25 with new prescriptions for all her topical and oral agents. She followed up three days later in the glaucoma clinic with pressure of 45 despite reported compliance with her current medications. After a visual fields test, it was determined to schedule the patient for emergency tube-shunting surgery the following day.
At the time of surgery, the patient was found to have significant peripheral anterior synechiae and residual neovascularization of the angle. These two factors caused the tunneling procedure for the tube insertion to be quite traumatic to the angle and anterior chamber. A large amount of viscoelastic was used to deepen the anterior chamber to better facilitate tube insertion. Despite this, there was a large hyphema that developed upon insertion of the tunneling needle. The anterior chamber was evacuated of the viscoelastic using a BSS washout. This washout was continued in order to best facilitate washing out the patient’s hyphema. Once it was determined that the tube was in a stable location and there was no anterior chamber leakage, the procedure was completed and the patient was sent home with the eye patched with instructions to follow up the next day.
Post op day one yielded a vision of 20/400 in the operated eye and pressure of 56. It was determined that there may be some retained viscoelastic in the anterior chamber, so the paracentesis was “burped” until the liquid protruding from the wound was determined to be of equal viscosity/consistency as aqueous. The patient had some residual hyphema settled at the base of the anterior chamber approximately 3.5 mm in height. The patient was instructed to maintain her head in constant elevation and to use topical prednisolone q2 hours with atropine BID.
On post op day six, the patient returned with vision decreased to hand motions and IOP of 53. The hyphema in the anterior chamber appeared to not only be increasing in height, but also had the appearance of occupying much of the aqueous in the superior portion of the AC including the area around the opening of the Baerveldt tube. At this time, it was determined that the blood from the hyphema was likely obstructing the tube. Upon slit lamp examination, it was not possible to visualize the Vicryl ligating suture given the anatomy of the patient’s orbit and degree of inflammation; therefore laser suture lysis was out of the question. Instead, it was decided that the next best approach to management would be AC paracentesis, followed by injection of 10 µcg of tPA (tissue plasminogen activator) in a concentration of 10 µcg/0.1 mL as compounded by the hospital pharmacy. After one hour, the superior, diffuse hyphema had somewhat cleared, and the intraocular pressure had been lowered to 21. The patient was discharged on the same medication regimen with instructions for continuous head elevation and to follow up in two days for another pressure check.
Post op day eight yielded a pressure of 53, and visual acuity decreased to light perception. The patient was given another AC paracentesis followed by tPA injection for two consecutive therapy courses separated over four hours. Return three days later yielded the same starting pressure and vision, with resulting IOP of 18 after one session of AC paracentesis and tPA injection.
Upon recording equivalent starting pressure of 52 and hand motions vision at 2 feet on day fourteen, it was determined that more aggressive intervention needed to be undertaken to preserve what remaining vision the patient had. The patient was consented for manual excision of the tube ligature in the minor operating room. Upon dissection to the level of the ligature, a large purplish-black clot of blood was visualized proximal to the point of interest. A number eleven blade was carefully inserted between the tube and suture, and subsequent lysis allowed the clot to flow from the tube into the body of the glaucoma device. After closure of the conjunctiva, the palpable IOP was determined to be in the mid teens.
The patient returned five days later, approximately post op day 20 with pressure of twenty. It was decided to continue current medical management and to have her follow up in one week. Post op day 26 yielded hand motion vision at 2 feet and IOP of 26. There was minimal hyphema present inferiorly, however a rather large and confluent blood clot could be visualized obstructing the opening of the tube in the anterior chamber, similar to the presentation at post op week one. Another AC paracentesis was performed, however this time an increased dose of intracameral tPA was injected at a concentration of 24 µcg/mL. After an hour, the patient was re-examined. The hyphema surrounding the opening of the tube was completely resolved, and there was little visible quantity of circulating blood cell visible in the aqueous. Applanation pressure was seventeen, and the patient appeared in much better condition than before.
Follow-up one week later showed almost no visible hyphema in the anterior chamber and IOP of 15 with hand motion vision at 4 feet.
Discussion:
In a prospective study by Zalta et. al, tPA was successfully used in valved glaucoma drainage implants in the treatment of post-operative tube obstruction by fibrin or blood. 88.9% of eyes were able to be cleared from obstruction with a mean number of injections totaling 1.6 The average dosage used per injection was 9.8 µg.
Kim et al used the same dosage system in the treatment of total hyphema in a case series of three eyes. After hyphema had been present five or more days, intracameral recombinant tPA was injected with complete resolution between 24 and 48 hours in all three eyes. The only observed complication from this series was vitreous hemorrhage which occurred after multiple injections in one of the three eyes.
Lundy et al performed intracameral tPA injections in patients with various forms of glaucoma surgeries, including filtering blebs and drainage implants. Their studies showed that dosages of tPA over 25 µg in a single dose led to hyphemas in the absence of pre-existing hyphema. To minimize the risk of hyphema, they recommended doses ranging between 6 and 12.5 µg.
In a rabbit model, Lambrou et al were able to achieve 80% clearance within 24 hours in randomized controlled trials in treating total hyphema. Their study did not find any increase in corneal thickness or intraocular pressure, and found that untreated eyes took fourteen days longer to achieve total clearance of the hyphema.
In summary, intracameral tPA administration can be a safe and effective procedure in dealing with complications of hyphema in the perioperative period in glaucoma patients. Judicious discretion must be used in frequency and concentration of dosing in order to safely achieve the desired results of hyphema clearance. Further studies regarding the benefits of direct tube cannulation would be beneficial in the management of hyphema in the tube-shunt neovascular glaucoma patient.
References:
- Zalta AH, Sweeney CP, Zalta AK, Kaufman AH. Intracameral tissue plasminogen activator use in a large series of eyes with valved glaucoma drainage implants. Arch Ophthalmol 2002;120(11):1487-93.
- Lundy DC, Sidoti P, Winarko T, et al. Intracameral tissue plasminogen activator after glaucoma surgery. Indications, effectiveness, and complications. Ophthalmology 1996;103(2):274-82.
- Lambrou FH, Snyder RW, Williams GA. Use of tissue plasminogen activator in experimental hyphema. Arch Ophthalmol 1987;105(7):995-7.
- Kim MH, Koo TH, Sah WJ, Chung SM. Treatment of total hyphema with relatively low-dose tissue plasminogen activator. Ophthalmic Surg Lasers 1998;29(9):762-6.
Have a question or comment on this article? Use the "Comment" link above to leave your thoughts, and the author will respond.