Ocular Hypotony Clinical Presentation

The following should be assessed in patients with ocular hypotony:

• Recent trauma or surgery

  • Glaucoma surgery with antimetabolites, a loosely sutured scleral flap, or a large track created to introduce a drainage device
  • 25-gauge vitrectomy surgery
  • Surgery requiring partial thickness scleral sutures, particularly in patients with myopia or abnormally thin tissue
  • Blunt trauma can cause a transient lowering of intraocular pressure (IOP)
  • Patients with a remote history of trauma can develop hypotony many years after the initial injury
• History of iridocyclitis or systemic illnesses predisposing to uveitis
• Blurred vision
• Eye pain (usually a deep ache), especially with choroidal detachment (Hemorrhagic choroidal detachment can cause extreme pain.)
• Signs and symptoms associated with retinal detachment
• Use of IOP-lowering medications, including recent exposure to anesthesia
• Severe dehydration, systemic hypertonicity, or acidosis

• Low intraocular pressure (≤ 5 mm Hg) after adjusting for extremely thin or thick corneal pachymetry: Individuals with very thin corneas (>500 microns) may register low uncorrected tonometer readings without any clinical signs or symptoms of hypotony. Conversely, those with thick corneas may exhibit hypotony at higher IOPs.
• Shallowing of the anterior chamber

  • Corneal edema and decompensation, especially in areas of corneal-iris touch (as is shown in the image below)Flat anterior chamber with iris-corneal touch following a phacotrabeculectomy.
  • Synechiae formation
  • Corneal astigmatism
• Seidel-positive wound leak (as is shown in the image below)Seidel-positive wound leak around a conjunctival suture.
• Large bleb following trabeculectomy or tube shunt (An eroded tube shunt is shown in the image below.)Eroded tube shunt in a patient with rheumatoid arthritis.
• Unplanned postoperative filtering bleb
• Hyperopic shift/reduced axial length
• Suspected traumatic globe rupture, especially if the following are present:

  • 360° of subconjunctival hemorrhagic chemosis
  • Peaked pupil
  • Hyphema
  • Intraocular foreign body
  • Preexisting weakness in the globe integrity, such as staphyloma, coloboma, or an old incision
• Inflammatory cells and flare in the anterior chamber
• Ciliochoroidal detachment, either serous or hemorrhagic
• Accelerated cataract formation
• Hypotony maculopathy^[1]

  • Macular thickening and folds seen on examination or optical coherence tomography (OCT) of the retina
  • Vascular engorgement and tortuosity
  • Optic disc swelling
• Cyclodialysis cleft seen on gonioscopy
• Retinal detachment

  • The anterior chamber is often deeper than usual when a retinal detachment is present.
  • Vitreous hemorrhage, evidence of penetrating injury, traction, or retinal hole is visible on funduscopic examination.
• Neovascularization of the iris in the setting of possible ocular ischemia

• Unilateral hypotony

  • Wound leak
  • Overfiltering or inadvertent bleb
  • Ciliary body detachment – Serous, hemorrhagic, or tractional
  • Cyclodialysis cleft
  • Inflammation - Iridocyclitis or blunt trauma
  • Retinal detachment or retinotomy
  • Ocular ischemia
  • Scleral perforation with needle or suture, or scleral rupture following trauma
  • Chemical cyclodestruction from antimetabolites
  • Photocoagulation or cryoablation of the ciliary body
  • Pharmacologic aqueous humor suppression
• Bilateral hypotony

  • Systemic hypertonicity or acidosis - Dehydration, uremia, uncontrolled diabetes, or use of hyperosmotic agents
  • Myotonic dystrophy