GLAUCOMA GRAND ROUNDS

Lesion Compounds Diagnosis In Young Glaucoma Suspect

by J. James Thimons, O.D.

A 37-year-old white female presented for a consultation and second opinion regarding a diagnosis of increased ocular pressure. The patient's general medical and ocular histories were negative. Family history was positive for glaucoma in both her mother and a sibling. She was taking no medications and had no known allergies.

Physical Examination
Uncorrected visual acuities were 20/20 O.U. and J1 at near. External exams showed pupils to be 4/4 /3+ Marcus Gunn. Extraocular motilities were within normal limits. Confrontation fields showed Fuchs' finger counting in all four quadrants and the external evaluation showed normal symmetry without evidence of trauma or physical abnormality.

The corneas were clear, the anterior chambers quiet and the irides and vitreous were unremarkable. Applanation pressures were 28mm Hg O.D. and 19mm Hg O.S. at 11 a.m. Gonioscopy showed ciliary body 360° O.U. with mild pigmentation and a normal iris surface. Visual field testing with a SITA standard package showed a normal visual field bilaterally. Dilated fundus exam showed cup-to-disc ratios of approximately 0.75 O.D. with erosion of the inferotemporal aspect of the disc and a visible laminar dot pattern, and 0.5 O.S. with a centrally located cup and a healthy neuroretinal rim and no presence of laminar dots. Measurement of the IOP at 7:30 a.m. showed pressures of 29mm Hg O.D. and 20 O.S.

Discussion
Assessment of this patient's risk factors demonstrated that she has both ophthalmic and non-ophthalmic concerns. The patient is Caucasian and young, but that is offset by her family history and the presence of asymmetric cup-to-disc ratio with elevated intraocular pressure. We decided to initiate therapy with a goal pressure in the high teens as a reasonable initial level. We did this in part because her left eye, at that level, showed no ocular nerve changes and a very healthy visual field function, and that the right eye's visual field was still normal in the presence of the asymmetric cup-to-disc ratio and IOP.

We placed her on Alphagan (brimonidine) BID O.D. and scheduled follow-up at one month. By then, IOPs had fallen to 20mm Hg O.D. and 18mm Hg O.S. I felt this was satisfactory as an initial therapy and that we could monitor the patient at a three-month follow-up to determine long-term efficacy.

Over the course of one year the patient demonstrated good IOP control with readings in the 18-21 range in the right eye and 17-20 in the left eye. Visual fields, optic nerve and nerve fiber layer were stable.

At the 18-month visit the patient demonstrated an unusual variation in iris architecture that presented as an elevated area inferotemporally in the right eye. This was not noted at any prior examination and the patient was unaware of its presence.

Gonioscopy revealed a mounded area approximately 1.5-2mm in diameter in the mid-iris. The angle itself could be visualized with minor movements of the gonio mirror and there was no evidence of compression or obstruction of the angular tissue by the lesion. Transillumination in a completely darkened room with the Fin Hoff revealed a very mild retroillumination of the mass. We felt at the time that this represented a stromal iris cyst.

We saw the patient again at about three months. The lesion remained stable in size and formation with no evidence of either vascular or pigmentary changes noted. Transillumination, while it was not dramatic, again showed evidence of a minor transillumination.

This patient presents an interesting variation in the pattern of glaucoma cases that we see in our practice. This is an early glaucoma case that has been well-controlled and has demonstrated good response to topical therapy. Concurrently she has developed an iris lesion that by clinical examination appears to be cyst-like, but we are still carefully monitoring it.

The natural history of this type of lesion is relatively benign and generally very slow. In such cases you should initially observe and photograph the lesion and subsequently follow the patient on a serial basis to determine any change. Also, in glaucoma one always has to rule out the possibility that the lesion contributes to the patient's underlying glaucomatous state.

This patient was widely dilated and we performed scleral indentation of the ora serrata with no evidence of pathological changes. We did a peripheral exam with simultaneous three-mirror scleral indentation in the area of the lesion to determine if a ciliary body extension was present. All of these were negative.

When the lesions cannot be transilluminated or demonstrate change over time, ultrasonic biomicroscopy would be indicated. This clearly demonstrates the anatomy of the lesion and enables a definitive diagnosis.

We've maintained this patient on current topical therapy with good results. We took photographs at the initial visit and are monitoring the lesion carefully at each follow-up. We do gonioscopy regularly to determine any variation in angular anatomy.

The patient's simultaneous disease presentation is unusual in open angle glaucoma. It creates a need for multi-aspect assessment and therapy, and requires regular review of each element to determine its status.