3. Problems with color vision

a.Objects have yellow tinge

b.Colored haloes around objects – mainly blue or yellow 4. Intraocular pressure

a.Initially increased – momentarily

b.Decreased – transient 5. Color hallucinations

6. Eyelids or conjunctiva – allergic reactions

7. Retinal vasodilatation – transitory

Conditional/Unclassified

1. Optic neuritis

Topical ocular application – inadvertent contact with liquid

Certain

1. Eyelids – erythema

2. Irritation – stinging pain

3. Cornea and conjunctiva

a.Sloughing of epithelial

b.Limbal ischemia

c.Edema

Clinical significance

Ocular side effects due to amyl nitrite are transient, reversible, uncommon and seldom of clinical significance. There is no evidence that these drugs have precipitated angle-closure glaucoma. Becker (1955) attempted to use amyl nitrite as a provocative test for angle-closure glaucoma, but was unsuccessful. Amyl nitrite ordinarily causes a slight rise of <3 mm of mercury for several seconds followed by a fall in intraocular pressure for only 10–20 minutes. This decrease in pressure is felt to be secondary to a fall in blood pressure. Fledelius (1999) reported a case of optic neuritis with irreversible loss of vision after amyl nitrite inhalation. Pece et al (2004) reported possible bilateral decreased vision and small yellowish-white foveal spots with improvement in time after isobutyl nitrite abuse.

These agents are used as recreational drugs and can come into contact with the eye in a liquid form. Mearza et al (2001) showed that anterior injury can be extensive, but heals without complication in time.

References And Further Reading

Becker B. In: Symposium on Glaucoma. Transactions of the first conference, Newell FW (ed), Josiah Macy Jr. Foundation, New York, p 32, 1955.

Cristini G, Pagliarani N. Amyl nitrite test in primary glaucoma. Br J Ophthalmol 37: 741, 1953.

Cristini G, Pagliarani N. Slitlamp study of the aqueous veins in simple glaucoma during the amyl nitrite test. Br J Ophthalmol 39: 685, 1955.

Fledelius HC. Irreversible blindness after amyl nitrite inhalation. Acta Ophthalmol Scand 77: 719–721, 1999.

Grant WM. Physiological and pharmacological influences upon intraocular pressure. Pharmacol Rev 7: 143, 1955.

Mearza AA, Asaria RHY, Little B. Corneal burn secondary to amyl nitrite. Eye 15: 333–334, 2001.

Pece A, Patelli F, Milani P, et al. Transient visual loss after amyl isobutyl nitrite abuse. Semin Ophthalmol 19: 105–106, 2004.

Robertson D, Stevens RM. Nitrates and glaucoma. JAMA 237: 117, 1977.

Generic names: 1. Diltiazem hydrochloride; 2. nifedipine; 3. verapamil hydrochloride.

Proprietary names: 1. Cardizem, Cardizem, LA, Cardizem XT, Cartia XT, Dilacor XR, Dilt-CD, Diltzac, Taztia XT, Teczem,

Tiazac; 2. Adalat CC, Afeditab CR, Procardia, Procardia XL; 3. Calan, Cover-HS, Isoptin, Isoptin SR, Verelan, Verelan pm.

Primary use

These calcium channel blockers are used in the treatment of vasospastic angina and chronic stable angina.

Ocular side effects

Systemic administration

Certain

1. Decreased vision

2. Eyelids or conjunctiva

a.Chemosis

b.Erythema

c.Conjunctivitis – non-specific

d.Photosensitivity

e.Angioneurotic edema

f.Urticaria

g.Purpura

h.Hyperpigmentation

3. Nystagmus – rotary (nifedipine, verapamil)

Probable

1. Periorbital edema

2. Visual hallucinations

3. Eyelids or conjunctiva – lupus erythematosus

Possible

1. Non-specific ocular irritation

a.Lacrimation

b.Photophobia (nifedipine)

c.Ocular pain (nifedipine) 2. Eyelids or conjunctiva

a.Stevens-Johnson syndrome

b.Toxic epidermal necrolysis

c.Erythema multiforme

3. Subconjunctival or retinal hemorrhages secondary to drug-induced anemia

Conditional/Unclassified

1. Blepharospasm

2. Retinal ischemia – transient (nifedipine)

Clinical significance

Ocular side effects are uncommon, reversible and seldom of enough clinical importance to stop the drug. The area of clinical interest is in the management of glaucoma. Intraocular pressure does not appear to be affected by calcium channel blockers, although there are questionable data that glaucoma patients may be more difficult to control on these agents. Nifedipine attenuates the intraocular pressure response to intubation following suxamethonium. Verapamil eyedrops have been shown to decrease episcleral venous pressure and intraocular pressure (Abreu et al 1998). There is increasing evidence that topical ocular beta blockers given to patients who are on calcium channel blockers may, in exceedingly rare cases, result in an arrythmia. This has been suggested in four separate reports by Pringle (1987), Sinclair and Benzie (1983), Staffurth and Emery (1981), Ansatassiades (1980), and in five cases within the National Registry. The proposed mechanism is that each agent acts in a different way to decrease the heart rate so the effects may be additive, causing an arrhythmia. Verapamil has been implicated in worsening myasthenia gravis (Swash and Ingram 1992) because of the drug’s inhibition of potassium outflow from cells at the motor end

agents renal and vascular Cardiac, • 6Stionec