Pigment Dispersion Glaucoma

Pigment Dispersion Glaucoma
SYMPTOMS Typically asymptomatic
In the later or more advanced stages, patients may report visual field loss such as scotomas or tunnel vision. If left untreated, complete blindness can occur
If IOP is too high (considered > 40mmHg), patient may experience Ocular pain, Pressure around the eye, Cloudy vision, Nausea, Vomiting, Headache, and Browache
SIGNS Typically bilateral
Krukenberg spindle, Pupil distortion in direction of majority of transillumination defects, Peripheral iris transillumination defects, Pigmented zonules, Zentmeyer ring or Scheie line, Iris pigment granules, Pigment floating in the anterior chamber especially post-dilated, Wide open angles on Van Herick, Deep anterior chamber
Glaucomatous optic nerve damage (notching, rim tissue thinning, cupping, vessel shelving, vessel bearing, vessel bayonetting), RNFL thinning, Drance hemes, Peripapillary atrophy
With advanced glaucomatous optic nerve damage, Optic nerve pallor will be present
WORK-UP Pupils (typically normal but can present with a decrease in light response if glaucoma is advanced or an APD if glaucoma is asymmetric), Color vision (typically normal), Slit lamp examination, IOP with GAT or ORA (typically elevated), Dilated retinal exam, Post-dilated IOP with GAT or ORA (typically elevated compared to IOPs measured before dilation), Fundus photos, Visual field with Humphrey 24-2/30-2/24-2C threshold or 10-2 threshold in more advanced glaucoma (nasal step, arcuate defect, paracentral scotoma, tunnel vision with temporal crescent sparing), OCT analysis of the optic nerve/RNFL/GCL (RNFL and GCL thinning with GCL loss typically preceding RNFL loss), OCT-Angiography (decrease in density of the radial peripapillary capillary plexus and superficial capillary plexus), Anterior segment OCT (wide open angles with a deep anterior chamber and concave iris approach with zonular contact), Gonioscopy (wide open angles with a uniform, heavily pigmented trabecular meshwork and Sampaolesi line especially in the inferior angle as well as a concave iris approach), Pachymetry (thin corneas carry a higher risk of glaucoma), Corneal hysteresis (low hysteresis carries a higher risk of glaucoma), VEP/Pattern ERG (decrease in ganglion cell function), Ultrasound biomicroscopy (wide open angles with a deep anterior chamber and concave iris approach with zonular contact)
TREATMENT Pigment dispersion syndrome with normal IOPs and no evidence of glaucomatous optic nerve damage: No treatment needed
Pigment dispersion syndrome with elevated IOPs but no evidence of glaucomatous optic nerve damage: Strongly consider treatment
Pigment dispersion glaucoma: Begin treatment
First-line of treatment would be a topical prostaglandin to be used 1 gtt QHS
If adjunct drop needed, consider a topical carbonic anhydrase inhibitor to be used 1 gtt BID
Rhopressa should be considered as the next adjunct drop to be used 1 gtt QHS
Alpha-2-agonists should be considered as the next adjunct drop to be used 1 gtt BID
Topical beta blockers should be considered as the next adjunct drop to be used 1 gtt once a day in the morning up to BID (the evening dose is thought to be minimally effective)
Consider using combo drops in order further lower IOP and improve compliance especially if patient is on multiple drops: Cosopt 1 gtt BID, Combigan 1 gtt BID, Simbrinza 1 gtt TID, Rocklatan 1 gtt QHS
Topical carbonic anhydrase inhibitors and alpha-2-agonists are to be used 1 gtt TID if utilized as stand-alone therapy
Pilocarpine 1-2% works well in patients with pigment dispersion syndrome as it reduces the irido-zonular contact but because of the numerous side effects (loss of accommodation, miotic pupils, increased risk of a retinal detachment), it is often not given to patients
Topical apraclonidine and oral acetazolamide can be given in-office or on a short-term basis to quickly lower IOPs
Always keep in mind the contraindications and side effects before prescribing any glaucoma medications
SLT may be used as a first-line of treatment in lieu of glaucoma drops or as an adjunct treatment along with glaucoma drops
LPI is an option for treatment as it reduces the irido-zonular contact due to resolution of the concave iris (IOP, however, may stay elevated)
If using more than 2 different types of glaucoma drops in order to manage patient, co-management with a glaucoma specialist should be considered
If using more than 3 different types of glaucoma drops, refer to glaucoma specialist for co-management
Patients with advanced, severe, or end stage glaucoma should be co-managed with a glaucoma specialist as further intervention such as blebs, MIGs, or shunts may be needed
FOLLOW-UP Pigment dispersion syndrome with normal IOPs and no evidence of glaucomatous optic nerve damage: Monitor every 6 months to 1 year
Pigment dispersion syndrome with elevated IOPs and no evidence of glaucomatous optic nerve damage (with decision made not to treat): Monitor every 4-6 months
Pigment dispersion glaucoma or pigment dispersion syndrome with elevated IOPs and no evidence of glaucomatous optic nerve damage (with decision made to treat): Patients should be seen back in 2-4 weeks after initiation of treatment in order to assess IOP (SLT and prostaglandins typically show maximal effectiveness at 4 weeks). After the initial assessment of IOP with treatment, patients are typically seen back every 3-4 months for glaucoma testing in order to look for progression
ADDITIONAL LAB | TESTS None
ETIOLOGY Reverse pupillary block facilitates the release of pigment as it increases the irido-zonular contact. Pigment deposits spread to the cornea, lens, and trabecular meshwork. Pigment in the trabecular meshwork leads to loss of porosity and dysfunction of the trabecular meshwork with subsequent increase in IOP
DIFFERENTIAL DX Primary open angle glaucoma, Pseudoexfoliative glaucoma, Pigmented guttata, Uveitic glaucoma, Iris melanoma
NOTES Patients with pigment dispersion syndrome tend to be younger (age of onset usually in the mid 20s) and myopic
Patients with pigment dispersion syndrome can have a “pigment storm” which causes a rapid, acute increase in IOP
About 33% of patients with pigment dispersion syndrome will develop glaucoma
The risk of developing glaucoma secondary to pigment dispersion syndrome decreases as a patient gets older
Pigment Dispersion Glaucoma: Gonioscopy image of a patient with pigment dispersion syndrome https://www.columbiaeye.org/education/digital-reference-of-ophthalmology/glacucoma/open-angle-glaucoma/pigment-dispersion-syndrome
Posted in Glaucoma, Ocular Conditions