Drug Induced Eye Conditions

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Drug Induced Eye Conditions

• Erin Lichtenstein
• September 2009

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Drugs effecting the cornea

• Vortex keratopathy
• Although deposits may involve the visual axis,
  vision is not impaired. Patients may notice
  haloes around lights.
• Causes Chloroquine and hydroxycholorquine,
  Amiodarone
• Whorl like corneal deposits, also called cornea
  verticillata
• Signs in order of occurrence
• Bilateral, fine grayish or golden-brown opacities
  in the inferior corneal epithelium
• Arborizing horizontal lines
• A whorl-like pattern which originates from below
  the pupil and swirls outwards, sparing the limbus

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Vortex keratopathy, con.

• Meperidine, Indomethacin, and Tamoxifen.
• Chloroquine and hydroxychloroquine
• Unlike retinopathy, keratopathy bears no
  relationship to dosage or duration of treatment
• Changes are usually reversible on cessation of
  therapy
• Amiodarone
• Almost all patients develop keratopathy
• Extent is related to dose and duration
• Resolves on cessation of therapy
• Other toxic effects anterior subcapsular
  cataracts and optic neuropathy

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More drugs effecting the cornea

• Chlorpromazine
• Used as a sedative and to treat psychotic
  illnesses
• Patients on long-term therapy may develop
  diffuse, yellow-brown granular deposits in the
  endothelium and the deep stroma
• Other effects include anterior subcapsular lens
  deposits and retinopathy

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More drugs effecting the cornea

• Gold Used in the treatment of rheumatoid
  arthritis
• Characterized by dust-like, glittering granules
  throughout the corneal stroma
• Do not effect vision

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Drugs causing cataracts

• Steroids Both systemic and topical are
  cataratogenic
• Lens opacities are initially posterior
  subcapsular and later the anterior subcapsular
  region becomes affected.
• Unknown dose and duration, however those on low
  dose chronically may be immune
• Children are more susceptible

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Drugs causing cataracts

• Chlorpromazine
• Causes the deposition of innocuous, fine,
  stellate, yellow-brown deposits on the anterior
  lens capsule
• Usually not visually significant
• Allopurinol
• Increases the risk of cataract formation if the
  cumulative dose exceeds 400g or duration exceeds
  3 years

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Drugs causing uveitis

• Rifabutin Used to treat Tuberculosis and MAC
  complex, typically presents with a unilateral
  acute uveitis, often with a hypopyon.
• Treatment is stopping the medication
• Cidovir Used in the management of CMV retinitis,
  causes acute anterior uveitis and vitritis.
• Treatment is with topical steroids and mydriatics

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Drugs causing retinopathy

• Chloroquine and hydroxychlorquine
• The former now rarely used for malaria treatment
  and prophylaxis, the latter is often used for
  rheumatologic conditions like SLE, rheumatoid
  arthritis, juvenile arthritis
• The latter is much safer than the former, and if
  the daily dose is less than 400mg, the risk of
  retinopathy is rare
• Risk is increased if daily does is 6.5 mg/kg for
  longer than 5 years
• Screening should be annual after having been on
  the medication for 5 years, although it often
  starts before this time
• Screening includes a thorough fundoscopic exam
  and a 10-2 AVF (detects the earliest changes)
• Recent studies suggest the a multifocal ERG may
  be the most effective way of screening early
  toxicity

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Stages of Chloroquine/Hydroxychloroquine
Retinopathy

• Pre-maculopathy
• Normal visual acuity, a small scotoma location
  between 4 to 9 degrees from fixation
• If drug stopped, vision usually returns to normal
• Early maculopathy
• Modest reduction in visual acuity to around 20/30
  or 20/40
• Fundus exam shows subtle bulls eye macular
  lesion, which may be more obvious on FA because
  the RPE atrophy gives rise to a window defect
• Moderate maculopathy
• Vision further reduced to around 20/60 or 20/80
  and the bulls eye lesion is much more obvious on
  exam
• Severe maculopathy
• Marked reduction in vision to 20/100, 20/200 and
  there is widespread RPE atrophy in the macula
• End-stage maculopathy
• Severe reduction in vision and marked atrophy of
  the RPE with unmasking of the larger choroidal
  vessels
• Retinal arteries may become attenuated and
  pigment clumping may develop in the peripheral
  retina

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Stages of Chloroquine/Hydroxychloroquine
Retinopathy
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Drugs causing retinopathy

• Phenothiazines (Thioridazine and
  Chlorporomazine)
• Used to treat schizophrenia
• Doses which exceed 800mg/day for a few weeks is
  sufficient to reduce vision and impair dark
  adaptation

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Phenothiazines, con.

• Clinical signs of progressive retinotoxicity in
  order are
• Salt and pepper pigmentary changes of the
  mid-periphery and posterior pole
• Pigment clumping and focal loss of the RPE
• Diffuse loss of the RPE and choriocapillaris

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Drugs causing crystalline maculopathy

• Tamoxifen
• Estrogen antagonist-agonist used to treat Breast
  CA
• Rarely can cause superficial, crystalline
  deposits in macula
• Visual acuity decreases are usually secondary to
  foveal cyst development
• Canthaxanthin
• An oral tanning agent
• Maculopathy reverses once drug is stopped
• Nitrofurantoin
• An antibiotic used in the treatment of UTI
• Long term use can lead to deposition in the
  superficial and deep retinal layers throughout
  the posterior pole

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Drugs causing maculopathy

• Interferon alpha
• Used to treat various conditions including
  Hepatitis C, cutaneous melanomas
• Causes a retinopathy similar in appearance to
  radiation retinopathy with cotton wool spots and
  intraretinal hemorrhages.

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Drugs causing maculopathy, con.

• Niacin
• Used to treat high cholesterol
• A small percentage of patients develop a
  maculopathy that appears like cystoid macular
  edema on exam and on OCT but does not leak on FA
• Resolves (see below) when Niacin stopped.

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Drugs causing optic neuropathy

• Ethambutol
• Used in combination with isoniazid and rifampin
  in the treatment of Tb.
• Toxicity typically occurs between 3 and 6 months
  of starting treatment
• VF defects usually consist of central or
  centrocecal scotomas
• Prognosis is usually good upon cessation of the
  medication but a minority of patients develop
  permanent visual impairment
• Amiodarone
• Antiarrhythmic drug used to treat atrial
  fibrillation and ventricular tachycardia
• Optic neuropathy only affects 1-2 of patients
  and is not dose related.
• Prognosis is guarded because cessation of the
  drug may not restore vision

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Drugs causing optic neuropathy, con.

• Vigabatrin
• An antiepileptic drug which causes nonprogressive
  bilateral binasal visual field defects.
• The defects persist once treatment is stopped but
  do not progress with treatment
• Viagra
• Controversial association with nonarteritic
  ischemic optic neuropathy
• 14 anecdotal case reports have reported, but may
  be coincidental
• Definitely does cause blue tinged vision which
  resolves

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Randoms

• Flomax
• An alpha-1 antagonist used to treat the urinary
  symptoms of BPH
• Makes cataract extraction difficult
• Causes the Floppy Iris Syndrome Symptoms
  include iris billowing and floppiness, iris
  prolapse to the main and side incisions, and
  progressive constriction to the pupil during
  surgery
• Topamax
• An anti-epileptic drug now more frequently used
  to treat migraine headaches
• Can cause a uveal effusion syndrome, with
  swelling of the ciliary body leading to pupillary
  block and angle closure.
• A myopic shift can also be seen.
• Occurs most often within 2 weeks of instituting
  treatment.

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References (material and all photos)

• Carter, John. Anterior ischemic optic neuropathy
  and stroke with use of PDE-5 inhibitors for
  erectile dysfunction Cause or coincidence?
  Journal of the Neurologic Sciences. Vol 262 15
  November 2007, Pages 89-97.
• Hamilton, Richard and Weinberg, David. Retinal
  Toxicity of Systemically Administered Drugs,
  Yanoff and Duker Ophthalmology, 3rd Edition.
  Mosby, New York, 2008.
• Kanski, Jack. Clinical Ophthalmology, 6th
  Edition. Elsevier, London, 2007.