Contact Lens Update

The PoLTF is the tear layer between ocular surface and contact lens back surface. It is made up of a thin aqueous phase (1µm) and of a compressed mucin phase (30-40µm). The mucin phase is of unknown thickness but it is probably at least marginally thinner than the pre-ocular tear film. The maintenance of the integrity of the mucin layer is essential to safe contact lens wear. The maintenance of the aqueous phase is essential to controlling the viscosity of the PoLTF and facilitating the elimination of back surface debris. The closed eye wearing period with it’s associated aqueous depletion and reduced lens movement produces the most challenging phase in EW. The period immediately upon eye opening is therefore the key recovery phase when PoLTF aqueous replenishment takes place.
Regarding silicone hydrogels, the following clinical practice is recommended:
• Follow-up visits should take place in the morning and include the evaluation of the PoLTF and the assessment of lens movement.
• Patients should be instructed to carry out self-evaluation of lens binding upon waking.
• Non-viscous eye drops such as saline (preferably single dose eye drops) should be dispensed for use upon waking.
Also see Lubricating drops.