Hyperosmotics, Miotics, Ptosis Drops, and Other Specialty Agents
Hypertonic saline for corneal edema (Muro 128)
Sodium chloride 5% (Muro 128) is a standard hypertonic agent that draws fluid out of the cornea via osmosis, reducing epithelial and stromal edema. Patients often notice the most benefit on waking, when edema is worst after overnight lid closure eliminates surface evaporation.
Fuchs endothelial dystrophy: Muro 128 is commonly used to improve morning vision by reducing edema enough to clear the visual axis. Ointment at bedtime provides longer contact time overnight, and drops during the day as tolerated. As endothelial cell loss progresses and edema becomes constant, Muro 128 becomes less effective and corneal transplant evaluation becomes relevant.
Recurrent corneal erosion (RCE): Hypertonic saline ointment at bedtime is a standard component of RCE management, supporting epithelial adhesion by reducing overnight stromal swelling that can loosen fragile epithelial attachments. Preservative-free artificial tears during the day and gentle lid hygiene complete the conservative regimen.
Glycerin for diagnostic corneal clearing
Topical glycerin (anhydrous or diluted) is a hypertonic agent that can temporarily clear corneal edema enough to allow a view of the anterior chamber, iris, and lens in situations where edema obscures examination. Common scenarios include acute angle-closure (where edema prevents gonioscopy or iris evaluation) and post-surgical corneal edema when a view of the IOL or anterior segment is needed. The effect is brief — usually minutes — so it is a diagnostic tool, not a therapeutic one. It can sting significantly on application.
Pharmacologic ptosis therapy: oxymetazoline 0.1% (Upneeq)
Oxymetazoline 0.1% (Upneeq) is an alpha-adrenergic agonist that stimulates Müller's muscle, producing a modest upper eyelid elevation (typically 1–2 mm) in patients with acquired blepharoptosis. It is most useful for mild to moderate ptosis when Müller's muscle function is intact.
Limitations: Upneeq does not correct dermatochalasis (excess eyelid skin), true levator dehiscence, third-nerve palsy, or most neurogenic ptosis. It should not replace surgical evaluation when superior visual field loss or significant functional impairment is present. Effect duration is approximately 6–8 hours per dose, so it is often used on an as-needed basis rather than continuous therapy.
Safety considerations: Systemic absorption is low but not zero. Review cardiovascular history, blood pressure control, and concurrent adrenergic medications. Document baseline lid position and MRD-1 before starting therapy.
Pilocarpine: miotics for angle-closure, testing, and presbyopia
Pilocarpine stimulates the iris sphincter (miosis) and the ciliary muscle (increased trabecular outflow). Although routine glaucoma management has largely moved to newer classes, pilocarpine remains relevant in several targeted scenarios:
- Pre-LPI preparation: Pre-treatment miosis tightens the peripheral iris in pupillary block or narrow-angle eyes before laser peripheral iridotomy.
- Adie tonic pupil testing: Dilute pilocarpine (e.g., 0.125%) may demonstrate denervation supersensitivity, constricting the Adie pupil while having minimal effect on the normal pupil.
- Presbyopia drops — pilocarpine 1.25% (Vuity): Low-concentration pilocarpine creates a small-aperture pupil effect that temporarily increases depth of focus for near tasks. The effect is modest and temporary (typically a few hours), and not all patients find the trade-off worthwhile. Dim-light visual quality, brow ache, and reduced peripheral vision are common complaints. Careful patient selection and realistic expectations are key.
Retinal safety: Pilocarpine causes ciliary muscle contraction that can increase traction on the vitreous base and peripheral retina. A small increased risk of retinal tears or detachment exists, particularly in high myopes or eyes with lattice degeneration. Consider a baseline dilated fundus exam before ongoing miotic use and give clear return precautions for flashes and floaters.
Low-dose atropine for myopia control
Low-dose atropine (0.01–0.05%) is used off-label to slow axial elongation and myopia progression in children. Multiple trials (ATOM, LAMP, and others) have demonstrated a dose-dependent reduction in myopia progression, with lower concentrations (0.01–0.05%) offering a reasonable balance of efficacy and tolerable side effects (minimal pupil dilation and accommodation loss compared to higher doses).
Atropine for myopia control is typically prescribed nightly in one or both eyes and continued for years during the period of active myopia progression. Commercially compounded formulations are most common, though FDA-approved options are emerging. Parents should be counseled that the treatment slows progression but does not stop or reverse it, and that the child still needs regular refractive monitoring, appropriate optical correction, and attention to outdoor time and near-work habits.
Cenegermin for neurotrophic keratitis (Oxervate)
Cenegermin-bkbj 0.002% (Oxervate) is a recombinant human nerve growth factor (rhNGF) that is FDA-approved for neurotrophic keratitis. It promotes corneal epithelial healing in patients with persistent epithelial defects that have not responded to conventional supportive measures (preservative-free lubrication, bandage contact lens, punctal occlusion, tarsorrhaphy). The standard course is six drops daily for eight weeks. It requires cold-chain storage and is significantly more expensive than standard topical therapies, so it is typically reserved for moderate to severe neurotrophic keratitis (Mackie stage 2–3) after simpler measures have failed. See the antivirals page for the distinction between neurotrophic keratopathy and active herpetic infection, which is critical before initiating cenegermin.