Medication Summary
Patients with pseudophakic pupillary block may experience sudden and prolonged increases in IOP. As soon as the patient presents with this condition, the greatest concern is to lower IOP as quickly as possible. The near normalization of ocular tension reduces operative and postoperative risks. Almost all glaucoma medications may be used (see Glaucoma, Primary Open Angle), including beta-blockers and alpha2-agonists, but miotics should be avoided. In addition, acetazolamide (a carbonic anhydrase inhibitor) and mannitol (a hyperosmotic agent) may be required; analgesics and steroidal and nonsteroidal medicines also may be needed. Postoperative medicines depend on the progress; in most cases, it is the instillation of antibiotic-steroid and antiglaucoma drops.
Carbonic anhydrase inhibitors
Class Summary
By slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport, it may inhibit carbonic anhydrase in the ciliary processes of the eye. This effect decreases aqueous humor secretion, reducing IOP.
Acetazolamide (Diamox)
Inhibits enzyme carbonic anhydrase, reducing rate of aqueous humor formation, which, in turn, reduces IOP. Used for adjunctive treatment of chronic simple (open-angle) glaucoma and secondary glaucoma and preoperatively in acute angle-closure glaucoma when delay of surgery desired to lower IOP.
Hyperosmotic agents
Class Summary
Hyperosmotic agents lower IOP by moving fluid out of the vitreous into the bloodstream. Cannot be used chronically due to the risk of dehydration and electrolyte imbalance (particularly hypokalemia). Mannitol is a highly effective medicine of this group. Given intravenously and highly suitable for patients with nausea and vomiting caused by severe rise in the IOP. Extremely useful for administration just prior to the surgery. Glycerine is a nontoxic, readily available hyperosmotic agent, to be administered by mouth, to tide over a period of crisis. Isosorbide is an important hyperosmotic agent that can be given safely to patients with diabetes.
Mannitol (Osmitrol, Resectisol)
For IV use, it is the first DOC, especially for preoperative use. Effective for a direct osmotic action, since it is distributed only in the extracellular space and penetrates very poorly in to the eye. The kidneys rapidly excrete it. Not metabolized and therefore suitable for patients with diabetes. DOC as hyperosmotic, for IV use. Adverse effects include urinary retention (due to excessive diuresis), headaches, back and chest pain, chills and rigors, nausea, vomiting, confusion, pulmonary edema, hypokalemia, and hyponatremia.
Glycerin (Ophthalgan, Osmoglyn)
Nontoxic drug absorbed rapidly after taking by mouth. Stable and easy to store. Has a very unpleasantly sweet taste. Frequently induces nausea and vomiting. Should be given chilled and flavored with lime powder or fruit juice over cracked ice. Metabolized, producing hyperglycemia; therefore, it is less suitable for patients with diabetes. Adverse effects include diarrhea, back pain, confusion, and hyperosmolar coma.
Isosorbide dinitrate (Ismotic)
Given by mouth, increases osmotic pressure of plasma in 2 ways. Before it is absorbed from the intestines, draws water in to intestines and causes hemoconcentration. Secondly, when it actually enters the blood, the osmolarity is increased. Tastes much better than glycerine. Not metabolized; therefore, suitable for patients with diabetes.
Cholinergics
Class Summary
Help treat iris bombe by breaking iris IOL adhesions. Useful only in early cases. Once firm adhesions have been formed, it is difficult to break them by local medication.
Atropine ophthalmic (Atropair, Isopto, Atropisol)
Most potent parasympatholytic agent available. By paralyzing the sphincter pupillae muscle, helps dilate the pupil. Also paralyzes ciliary muscle. Effect lasts 7-10 days.
Sympathomimetic agents
Class Summary
When combined with parasympatholytics, provide the best chance of dilating the pupil.
Phenylephrine ophthalmic (Neo-Synephrine)
Selective alpha1-agonist induces mydriasis and vasoconstriction and reduces IOP. Maximum effect is produced in 30 min and remains for several hours. Combined with anticholinergic drugs, produces maximal mydriasis.
Corticosteroids
Class Summary
Inflammation is a constant accompaniment of patients with pseudophakic pupillary block. Steroid drops are very effective in reducing intensity of inflammation. Steroids control practically all aspects of the inflammatory process and immune response. Their main activity occurs at the actual site of inflammation; therefore, topical application in the eye suppresses inflammation.
Prednisolone acetate 1% (Pred Forte)
Most effective as anti-inflammatory agent on anterior segment of the eye. Frequent application needed to get maximal effect.
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Pseudophakic pupillary block precipitated by leakage of the incision line. This led to a chain reaction of forward movement of the posterior chamber lens, closure of the angle, intractable glaucoma, and iris-cornea touch over a wide area.
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Same patient as in the image above, 1 month after surgery. She underwent iridectomy at 3 places, separation of the iris from the cornea and the optic of the intraocular lens with viscoelastic material, and ab-interno filtration procedure at the 6-o'clock position, with erbium laser. The intraocular pressure is 13 mm Hg.
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Pupillary block in the presence of a posterior chamber lens. This stereo pair shows the closure of the peripheral iridectomy, dilated pupil, iris lens adhesions, and fibrotic membrane formation in the whole of the pupillary area. A large area of the iris shows iris bombe formation.
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This 5-year-old child, a case of congenital cataract, earlier had pupillary block and moderate iris bombe, which was relieved by 2 shots of Nd:YAG on the ballooned iris and the peripheral iridectomy opening.Two weeks later, he came back with a much worse pseudophakic pupillary block and multiloculated ballooning of the iris. The intraocular pressure was raised. Pigment and exudates were on the surface of the intraocular lens. The condition was relieved by reopening the peripheral iridectomy site, removing the posterior capsule in the pupillary area; performing iridectomy along the upper pupillary margin, a small central anterior vitrectomy and cleaning the intraocular lens with the help of a vitrector. The anterior chamber was deepened with a large air bubble. The recovery was uneventful.
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One month postoperatively of the patient above, the cornea was clear, the anterior chamber was deep, a few peripheral anterior synechiae were present, the pupillary area was clear, the pigment on the periphery of the intraocular lens had been reduced, the intraocular pressure was normal, and corrected visual acuity was 20/80. The patient remained free from a pupillary block thereafter.
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Pseudophakic pupillary block observed in a case of posterior chamber lens. The pupil is closed and deformed by the optic of the lens and the fibrous tissue, but the consequences of pupillary block are missing due to the presence of a patent peripheral iridectomy.
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The patient is 6 years old. Closure of peripheral iridectomy, lens decentration, partial pupil capture, and adhesions between the optic and the iris have produced pupillary block. One of the loops has started cheese-wiring the iris. Iris bombe is all around. Iris incision line adhesions are visible. The intraocular pressure is normal.
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With the help of a vitrector, the central part of the iris has been moved over and close to the optic. No attempt has been made to reposition the optic of the lens. The peripheral iridectomy is left as such. The iris bombe has settled nicely.
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Pediatric iris claw lens implantation, showing a pupillary block that has been precipitated by the closure of the peripheral iridectomy with Elschnig pearls. The pupil has been closed with the optic of the lens. A vertical fibrotic band courses vertically across the edge of the optic. The 360º iris bombe has encouraged adhesion formation between the iris and the perimeter of the lens.Treatment in these cases involves removing Elschnig pearls, opening and enlarging the existing iridectomy, making an additional iridectomy elsewhere, cutting the fibrous band, separating the iris from the optic, doing a small anterior vitrectomy, and enlarging the pupil with a vitrector toward the 12-o'clock position (so that the edge of the pupil goes beyond the edge of the optic).
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The stereo pair shows pseudophakic pupillary block in a brown eye. No peripheral iridectomy is visible. The pupil is dilated, and the iris is adherent to the optic of the lens. An amorphous, translucent membrane is present on the surface of the lens. The treatment involves a surgical iridectomy, clearing the optical axis of any obstacle, and performing a small anterior vitrectomy.
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A 60-year-old patient with a light-colored iris presents with pseudophakic pupillary block. Lens implant surgery was performed 6 months ago. The pupil is dilated moderately. There are adhesions with the optic of the posterior chamber lens. One loop of the lens is pushing itself into the anterior chamber. Iris bombe is seen in 360º. Most of the iris from the 6-o'clock position to the 11-o'clock position is in contact with the endothelium. A round continuous curvilinear capsulorrhexis is visible, in front of which the optic of the lens lies. The patient has been experiencing eye aches for 2 months. Intraocular pressure is 35 mm Hg. A filtration operation for glaucoma with 1 or 2 iridectomies suffices for control of glaucoma and for clearing the pupillary block. Further intervention depends on the progress of the case.
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A 56-year-old patient presents with a 4-loop-angle-supported lens. Two loops are visible, while the other loops are hidden under the iris tissue. From the 10-o'clock position to the 3-o'clock position, the edge of the optic is hidden under the overgrown iris tissue. A translucent membrane, 4-cornered in shape, is adherent to the anterior surface of the optic. A peripheral iridectomy is not visible. The pupil is blocked with pigment and scar tissue. The optic of the lens is acting like a perfect lid over the pupil. Iris bombe is all around, more so in the upper half. The endothelial cell count is 1700 cells/mm2. By a quirk of nature, the intraocular pressure is still normal. Light perception and projection are good. An iris claw lens, although virtually unknown in some parts of the world, is an excellent exchange lens. It can be fixed with minimal trauma to the iris and is well tolerated.
