Optimal solutions for visual recovery
The TD-K application protocol is recommended for non-advanced cases of keratoconus (KC) and pellucid marginal degeneration (PMD), when good visual recovery can be achieved through maximum spherical-cylindrical correction.
TD-K bi-toric lenses are selected based on refraction data and visual acuity, and are particularly useful in cases where the subject has difficulty adapting (discomfort) to other corrective solutions, such as spectacles or R(GP) lenses.
The specific design, developed for ectasia, combined with Hydrogel and Silicone Hydrogel polymers, ensures that physiological conditions are maintained while wearing the lenses.
Geometric characteristics
- Internal toric lens with specific design for ectasia.
- Dedicated and optimised dynamic stabilisation.
- Differentiated thicknesses and optical zones.
Selection of the carrier
Determine the ophthalmic correction for best corrected visual acuity (BCVA): if the value is greater than 5-6/10, even in the presence of a high spherical-cylindrical prescription, this result can be improved by applying a TD-K lac.
The Bi-Toric option ensures visual performance by correcting residual astigmatism.
The Bi-Toric option ensures visual performance by correcting residual astigmatism.
Application procedures
- From the Trial-Set TD-K, adapt the lens with the axis and corrective cylinder closest to the refraction data.
- Wait 30 minutes after insertion, then evaluate:
- Blink and Push-Up test dynamics
- Corneal coverage ratio: TD vs HVID
- Orientation of the reference lines and any rotation of the markings
- Measure BCVA in subjective over-refraction and define the optimal values: Sphere, Cylinder and Axis.
Clinical notes
- If BC and/or TD are not adequate, select new parameters to stabilise the lens.
- If there is rotation of the markings, replace the trial lens, compensating for the axis according to the normal application criteria for soft toric lenses.
Order of the Definitive Lens
Using TSLAC vector software, determine the lens correction to be ordered:
- Add the over-refraction data to the power of the tested lens and enter the entity and axis of rotation of the reference lines.
- Communicate the result obtained from the vector calculation and the data relating to the power and axis of the tested TD-K lens to Professional Service.