Medical & osmotic therapy

When edema is mild and morning-limited, osmotic therapy often restores acceptable comfort. Hypertonic 5% sodium chloride (drops by day, ointment at bedtime) draws water out of the cornea, most helpful on waking. Evaporative dehydration — warm airflow to the open eye in the morning (hair-dryer at a distance) — usefully adds to this. IOP control is a logical adjunct: lower pressure eases the pump's work.

When painful bullae form, a bandage contact lens protects exposed nerve endings; amniotic membrane and, in eyes with poor visual potential, palliative covering procedures relieve symptoms. These measures do not change the natural history: they buy time before surgery, or substitute for it when surgery is not indicated.

Descemet Stripping Only (DSO/DWEK) & ROCK inhibitors

7.1 DSO / DWEK — clearance without a graft

In selected patients — symptomatic central guttata with preserved peripheral endothelial reserve (on the order of ≥ 1,000 cells/mm²) — one can dispense with a graft: a central descemetorhexis of about 4 mm removes the diseased zone and lets peripheral cells migrate to recolonise the centre. The technique avoids the immunological hazards of a graft and preserves tissue reserve.

Its limits dictate selection. It requires sufficient peripheral reserve and a measured descemetorhexis diameter (avoid > 4–4.5 mm); it is contraindicated in diffuse or advanced forms (extensive edema, globally rarefied endothelium), where no migration will fill the centre. Clearance is slow and unpredictable (weeks to months), and a proportion of cases fail to clear, requiring rescue endothelial keratoplasty. An elegant but narrow option, reserved for a precise profile.

7.2 Rho-kinase (ROCK) inhibitors — stage-dependent

ROCK inhibitors (ripasudil, netarsudil) stimulate cell cycle, migration and adhesion, restore pump and barrier protein expression, and slow endothelial-mesenchymal transition (EndoMT); an effect has been seen even with guttae. Their role depends closely on stage: