Steroid Induced Glaucoma

Steroid Induced 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 unilateral
Open angles on Van Herick with no signs of secondary glaucomas
Signs of ocular inflammation such as cells, flare, posterior synechiae, and subepithelial infiltrates may be present (indications for steroid use)
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 (elevated), Dilated retinal exam, Post-dilated IOP with GAT or ORA, 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), Gonioscopy (angles should be open with no anomalies), 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)
TREATMENT Discontinue steroid use if possible (when the steroid is discontinued, IOPs will quickly return to normal except in about 3% of steroid responders who will have IOPs that remain elevated and not return to normal)
Consider switching to a softer steroid (i.e. a steroid that is less likely to cause an elevation in IOP)
If the patient needs to remain on the steroid that is causing elevated IOP, glaucoma therapy should be initiated (glaucoma treatment will typically be temporary as the IOP tends to quickly return to normal once the steroid is discontinued but patients may need to use glaucoma therapy for a more permanent basis in cases of intravitreal steroids, in patients who will continue to have elevated IOPs despite discontinuing the steroid, and in patients with glaucomatous optic nerve damage)
First-line of treatment would typically be a combo drop which includes Cosopt 1 gtt BID, Combigan 1 gtt BID, or Simbrinza 1 gtt TID in order to quickly lower the IOP
If adjunct drop needed, consider Rhopressa which is to be used 1 gtt QHS
Topical carbonic anhydrase inhibitors to be used 1 gtt BID. alpha-2-agonists to be used 1 gtt BID, and/or topical beta blockers to be used 1 gtt once a day in the morning up to BID (the evening dose is thought to be minimally effective) can be considered as adjunct treatment (as long as class of medication is not currently being used in the first-line combo glaucoma drop)
Topical carbonic anhydrase inhibitors and alpha-2-agonists are to be used 1 gtt TID if utilized as stand-alone therapy
Topical apraclonidine and oral acetazolamide can be given in-office or on a short-term basis to quickly lower IOPs
Prostaglandins, pilocarpine, and Rocklatan (due to prostaglandin component) should be avoided due to the risk of exacerbating ocular inflammation and the longer time it takes to achieve a therapeutic effect
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
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
If a patient presents with elevated IOP secondary to an intravitreal steroid injection or implant, the patient may need to be referred to a retinal specialist for a vitrectomy or removal of the implant
If a patient with elevated IOP was prescribed the steroid elsewhere (i.e. from a primary care provider or dermatologist), that physician should be contacted to see if the steroid can be discontinued or changed
FOLLOW-UP If starting patient on a topical steroid short-term, the patient should have IOP checked within 2 weeks (IOP spikes on average occur within 2 weeks)
If starting patient on a topical steroid long-term, the patient should have IOP checked within 2 weeks, then monthly for the next 2-3 months, and then every 3-6 months if treatment is to continue
If starting patient on an oral steroid long-term, the patient should have IOP checked within 1 month, then in 3 months, and then every 6 months if treatment is to continue (if oral steroids are going to be used on a short-term basis, the risk of an increase in IOP is low due to first pass hepatic metabolism)
If current steroid is discontinued or changed, the patient should return within 1-2 weeks in order to reassess the IOP
If glaucoma treatment is initiated, the patient should be seen back in 2-4 weeks after initiation of treatment in order to assess IOP. 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
If a patient received an intravitreal steroid injection, the patient should have IOP checked within 1 week, then every 2 weeks for the first month, and then every month for 6 months
If a patient received an Ozurdex intravitreal implant, the patient should have IOP checked within 2 week, then every 2 weeks for the first month, and then every month for 6 months
If a patient received an Iluvien or Retisert intravitreal implant, the patient should have IOP checked within 2 week, then every 2 weeks for the first month, and then every month for 9 months
After seeing the retinal specialist for a vitrectomy or removal of the intravitreal steroid implant, monitor every 3-4 months. The patient will most likely need to be on topical glaucoma drops long-term
ETIOLOGY Decrease in beta receptor response causes an increase in glycosaminoglycans, fibronectin, collagen, and elastin in the trabecular meshwork which leads to a decrease in outflow
Suppression of phagocytic activity and reversible crosslinking of actin fibers in the trabecular meshwork additionally leads to a decrease in outflow
Linked with the mutation of the myocilin gene which leads to increased secretion of the trabecular meshwork-inducible glucocorticoid response protein (TIGR)
DIFFERENTIAL DX Primary open angle glaucoma, Traumatic glaucoma, Pseudoexfoliative glaucoma
NOTES Routes of steroid administration that are likely to cause a steroid response from highest risk to lowest risk are intravitreal (especially intravitreal steroid implants), topical (especially dexamethasone, prednisolone, and difluprednate), periocular, dermatologic, endogenous, intravenous, oral, and inhaled
Of all the topical steroids, Durezol has the highest risk of causing a steroid response
A topical steroid used in only one eye can actually cause a steroid response in both eyes (eyelid closure for 2-3 minutes after installation of the topical steroid will reduce systemic absorption by 60%)
Risk factors for steroid response glaucoma include having primary open angle glaucoma (increases risk by 90%), having normal tension glaucoma (increases risk by 100%), having traumatic glaucoma, having a family history of glaucoma, being a glaucoma suspect (increases risk by 30%), being a child < 10 years old, having type 1 diabetes, having connective tissue diseases, having a history of LASIK or a penetrating keratoplasty, and having high myopia
The Armaly classification of a steroid response is based the increase in IOP: Low < 6mmHg increase in IOP / Moderate 6-15mmHg increase in IOP / High > 15mmHg increase in IOP
The Becker classification of a steroid response is based on the IOP measurement itself: Low < 20mmHg / Moderate 20-30mmHg / High > 30mmHg
The majority of glaucoma patients tend to be in the moderate - high categories of both the Armaly and Becker classification
Steroid Induced Glaucoma: Visual field threshold shows an arcuate defect associated with superior RNFL and GCL loss