GENERALITY
The use of diagnostic lenses is the only way to properly assess the correct fit and final lens power.
Topical corneal anesthetic is recommended for new fits to reduce tearing for more accurate fitting assessment.
Toric peripheral curves and Asymmetric Corneal Technology (ACT) are available on all lens designs.

Rose K2 / Rose K Rose K2 IC Rose K2 Post Graft   Indications Nipple Keratoconus, Oval Keratoconus Pellucid Marginal Degeneration, Keratoglobus, LASIK induced Ectasia and Post Graft For patients who have undergone penetrating keratoplasty Initial base curve selection COMPUTE AVERAGE K SELECT INITIAL BASE CURVE 5.90 mm and steeper 0.20 mm steeper than average K > 6.0mm < 6.90mm Equal to average K 7.0 mm and flatter 0.40 mm flatter than average K PMD AND GLOBUS, 0.3 mm flatter than steepest corneal meridian. POST LASIK AND GRAFT, refer to Rose K Post Graft section. 0.3 mm steeper than average K reading. Central fit Ignore peripheral fit at this stage.  A Evaluate central fit immediately after blink when lens is centered.  B A light, feather touch at the apex of the cone is desired. (See fluorescein images section). Ignore peripheral fit at this stage. A Evaluate central fit immediately after blink when lens is centered. B FOR PMD AND GLOBUS, a light feather touch is desired. FOR POST LASIK, look for central pooling of 0.2 mm to 0.3 mm. FOR POST GRAFT, refer to Rose K Post Graft section. (See fluorescein images section). Ignore peripheral fit at this stage. A Evaluate central fit immediately after blink when lens is centered. B Look for central pooling of 0.2 mm to 0.3 mm in early flatter grafts; alignment to 0.1 mm flatter in more mature grafts. (See fluorescein images section). Peripheral fit Once good central fit is achieved, assess edge lift. Look for an even fluorescein band of 0.5 mm to 0.7 mm in width. Order increased (flat) or decreased (steep) edge lift accordingly. For asymmetric edge lift where the lift is excessive at 12 and 6 o'clock and insufficient at 3 and 9 o'clock, consider toric PCs (TP design). For significant edge stand off / lift off, at or around 6 o'clock, consider ACT. Assess the diameter The standard diameter is 8.7 mm. Smaller diameters (8.3 mm) work well on very steep nipple cones. A larger diameter is often required for early cones and will also tend to make the lens ride higher. The lens should hang off the top lid and be well clear of the lower limbus. The standard diameter is 11.2 mm. Increasing the diameter will help lens location/centration. Make sure the lens is not impinging onto the upper sclera. The standard diameter is 10.4 mm. Increasing the diameter will help lens location/centration. Make sure the lens is not impinging onto the upper sclera. Assess power last Perform over refraction in well-lit room. Over refract using ± 1.00D steps initially and refine with 0.50D and 0.25D steps. Residual astigmatism (R.A.) It is usual to leave low amounts of R.A. uncorrected, or to compensate spherically for it (see table). It is rare to see R.A. amounts over this level; when it is, toric lenses (front, back or bi-toric) are usually needed. Please call your Rose K distributor for more information on toric lenses.