New England Eye Center Grand Rounds

Ihuoma U. Alozie-Uddoh, M.D.

April 26, 2001

New England Eye Center Grand Rounds

Case Presentation:• 38 year old male presents on 28/3/01 for a second

opinion regarding fluctuating and poor vision OS since glaucoma surgery in his left eye on 20/11/2000. There was no history of pain, headaches, nausea, vomiting or trauma associated with the decline in vision.

New England Eye CenterGrand Rounds

• Case Presentation:• Past Ocular History:

– Preoperative intraocular pressures 15-20 mm Hg OU, with progressive field loss on maximal medical therapy.

– Myopic astigmatism OU, with the following refraction.

• OD: -1.50 –0.50 x 010;

• OS: - 1.25 –0.50 x 180.

– Preoperative visual acuity 20/20 OU

New England Eye Center Grand Rounds

• Case Presentation:• POAG OU. • 20/11/00

– S/P trabeculectomy (fornix based) with mitomycin C 0.2 mg/cc x 3mins OS

• 21/11/00– POD#1: VA OS 20/20, IOP OS 6 mmHg. – POD#2: flat bleb, shallow anterior chamber and limbal conjunctival wound leak

noted. IOP 0 mm Hg with retinal folds. Bandage contact lens placed, no resolution of hypotony.

• 10/12/00 Bleb leak was repaired surgically.– POD #1 IOP 10mmHg VA 20/60 with persistent retinal folds. – POD #2 IOP 0mmHg VA 20/200

New England Eye CenterGrand Rounds

• Case Presentation:• Past Medical History: Unremarkable • Family History: Mother and sister with POAG.

Father with ARMD• Meds: Latanoprost 0.005% OD qhs, Timolol 0.5%

XE OD qam, ciprofloxin OS qd.• Allergies: Penicillin

New England Eye Center Grand Rounds

• Case Presentation:• On presentation, BCVA 20/20 OD and 20/200 OS. • Pupils were 4mm OU, reactive to light and accommodation

with no relative afferent pupillary defect OU.• Intraocular pressures were 15mmHg OD and 02mmHg OS

at 1:30pm. • SLE

– 2+ diffuse elevated bleb with anterior chamber depth of 1 corneal thickness centrally and peripheral iris touch OS. 2+ corneal striae. There was a patent iridotomy at the 12o’clock position OS.

– Anterior segment examination was within normal limits OD.

Figure 1. Visual fields photographs of Right and Left Eyes

Figure 2. Red Free Photographs of Right and Left Eyes

Figure 3. Fluorescein angiography of Right and Left Eyes.

0:22 0:51

8:44 8:57

New England Eye Center Grand Rounds

• Case Presentation:• Gonioscopy

– Angles open to ciliary body band OU. There was no cyclodialysis cleft noted in either eye.

• Dilated fundus examination– marked cupping of the optic nerve OD with thinning of

the nasal rim. There was cupping of the optic nerve OS as well. There was tortuosity of the retinal vessels, with choroidal folds and macular striae OS. The rest of the fundus examination was normal OD.

New England Eye Center Grand Rounds

• The differential diagnosis of hypotony with decreased visual acuity after surgery is:– Hypotony maculopathy

– Wound leak

– Cyclodialysis cleft

– Excessive filtration

– Choroidal detachment

– Retinal detachment

New England Eye Center Grand Rounds

• Case Presentation:• Based on the clinical presentation, the patient was diagnosed with

hypotony maculopathy and underwent surgical revision of the scleral flap OS.

• Operative procedure:

• Placement of two 10-nylon sutures to both sides of triangular scleral flap.

• Closure of limbal based conjunctival flap

– POD #1:

• IOP increased to 28mmHg OS and visual acuity improved to 20/40.

New England Eye Center Grand Rounds.

• Discussion• Hypotony maculopathy is a condition that occurs when

chronically low intraocular pressure induces secondary posterior segment changes such as choroidal folds, retinal folds and optic disc edema.

• It is seen most frequently as a complication of glaucoma surgery with sustained intraocular postoperative IOPs below 5 mm Hg.

• Risks factors for developing Hypotony Maculopathy include primary trabeculectomy, myopia, young age and the use of antimetabolites.

• Hypotony maculopathy rarely occurred after filtration surgery before the introduction of antimetabolites.

New England Eye Center Grand Rounds.

• Discussion• The pathophysiology of hypotony maculopathy is unclear.

It has been suggested that prolonged hypotony could cause the scleral wall to collapse inward, resulting in redundancy of the choroid and the retina leading to chorioretinal wrinkling.

• Cystoid macular edema rarely develops, and the loss of central vision that is seen in hypotony maculopathy is regarded primarily as a result of the chorioretinal folds in the macular area. The folds distort the image and reduce the axial diameter of the eye, inducing relative hyperopia.

New England Eye Center Grand Rounds.

• Discussion• Factors other than intraocular pressure such as scleral

rigidity, scleral thickness, choroidal vascular patterns and extraocular muscle tone have been implicated in the pathophysiology of visual loss with hypotony.

• Most cases of hypotony maculopathy occur after a significant event such as laser suture lysis, bleb leaks, needling procedures and immediately after surgery.

New England Eye Center Grand Rounds.

• Discussion:• The use of antimetabolite drugs such as 5-FU and

mitomycin C in glaucoma filtration procedures is associated with the risk of excessive filtration after surgery.

• By promoting the formation of such large blebs, mitomycin C may contribute to the development of hypotony maculopathy.

• Mitomycin C may also have a direct, toxic effect on the ciliary body epithelium.

New England Eye Center Grand Rounds

• Discussion• Mitomycin C is usually used at a concentration of

0.2-0.5mg/cc and is titrated for time based on the severity of the glaucoma being treated.

• There is no general concensus as to the safe dose of mmc to be used to avoid hypotony maculopathy. Generally reoperations require longer times of application and primary filters shorter times of application as well as lower concentrations.

• 5FU has fallen out of favor due to the necessity of frequent applications and the corneal toxicity associated with recurrent applications. As a result, most cases of hypotony maculopathy seen are associated with mitomycin c use.

New England Eye Center Grand Rounds.

• Discussion• Hypotony maculopathy, once diagnosed, is a difficult

condition to treat. Given the profound effect of chronic macular folds on visual acuity and the natural history of hypotony maculopathy after filtering surgery, observation is of questionable benefit.

• Visual prognosis seems to be correlated with the duration of hypotony. The best time intervene is unclear, but many studies suggest that in a young myopic patient with postoperative hypotony that fails to return to preoperative visual acuity within 12 weeks, some attempt at reducing filtration should be considered.

New England Eye Center Grand Rounds.

• Discussion• Gonioscopy and a careful slit-lamp examination should be done to

rule out cyclodialysis clefts and conjunctival wound leaks, which are both treatable causes of ocular hypotony.

• There have been four main approaches applied in the treatment of hypotony maculopathy.– Placement of an oversized contact lens– Stimulation of fibrosis on the bleb wall by an irritant or blood.– Mechanical flattening of the macula– Revision of the scleral flap

New England Eye Center Grand Rounds.

• Discussion:• To avoid complications of hypotony maculopathy

– Restriction of use of mitomycin C to cases in which surgical prognosis is poor, or single digit IOP is desired

– Prudent use in patients with decreased scleral rigidity, such as the young myopic patient.

– Exercising more control of the aqueous flow by placement of extra sutures on the scleral flap.

– Careful releasing of trabeculectomy flap sutures.

New England Eye Center Grand Rounds.

• Summary:• 38 year old myopic male who developed profound

visual loss from hypotony maculopathy after a primary trabeculectomy with mitomycin C in the left eye. After resuturing of the scleral flap, VA improved to 20/40 and IOP increased to 28.

New England Eye Center Grand Rounds.

• References:• Costa VP, Wilson RP et al. Hypotony Maculopathy Following the Use of Topical

Mitomycin C in Glaucoma Filtration Surgery Ophthalmic Surgery June 1993 24: 389-394.

• Duker JS, Schuman JS. Successful Surgical Treatment of Hypotony Maculopathy Following Trabeculotomy with Topical Mitomycin C. Ophthalmic Surgery July 1994;24:463-465.

• Haynes WL, Alward WL. Combination of Autologous Blood Injection and Bleb Compression Sutures to Treat Hypotony Maculopathy. Journal of Glaucoma 8:384-387.

• Shields MB, Scroggs MW et al. Clinical and Histopathlogic Observations Concerning Hypotony After Trabeculectomy with Adjunctive Mitomycin C.American J. of Ophthalmology 116:673-683, Dec. 1993.

• Skuta GL, Beeson CC et al. Intraoperative Mitomycin versus Postoperative 5-Fluorouracil in High risk Glaucoma Filtering Surgery. Ophthalmology 1992; 99:438-444.

New England Eye Center Grand Rounds.

• References:• Stamper RL, McMenemy MG, Lieberman MF Hypotonous Maculopathy

After Trabeculectomy with Subconjunctival 5-Fluorouracil. Am. Journal of Ophthalmology 114:544-553, Nov, 1992.

• Suner IJ, Greenfield DS et al. Hypotony Maculopathy after Filtering Surgery with Mitomycin C. Ophthalmology 1997;104:207-215

• Wise JB. Treatment of Chronic Postfiltration Hypotony by Intrableb Injection of Autologous Blood Arch Ophthalmol June 1993 111:827-830.

• Zacharia PT, Depperman SR, Schuman JS. Ocular Hypotony after trabeculectomy with Mitomycin C. American J. of Ophthalmology 116:314-326, Sept. 1993.