Downloaded 23 times
More Related Content
Similar to Rose K lens.pptx
Rose K lens.pptx
- 1. Rose K lens SEMINARPRESENTATION
- 2. Introduction The ROSEK family of lenses was invented by Paul Rose, an optometrist from Hamilton, New Zealand Complex geometry closely mimics the cone-like shape of the cornea for every stage of the condition The ROSE K lenses’ are computer-controlled and lathes were developed to cut sophisticated oxygen permeable polymers to the right shape.
- 3. Advantages The ROSEK lens has a number of features: Its complex geometry can be customized to suit each eye Easy to insert, remove and clean Provide excellent health to the eye, cornea "breathe" oxygen directly through the lens Achieves a first fit success in over 80% of patients internationally
- 4. Design Features Simpleto use flexible edge lift system Aberration control aspheric optics providing outstanding visual acuity, reduced flare and glare and minimum lens mass Advanced fitting options - toric peripheral curves, Asymmetric Corneal Technology (ACT), front, back and bi-toric designs, and quadrant specific edge lifts
- 5. Standard lens designswith fixed optical zones (OZ) do not ideally fit the cone shape of keratoconus patients. Figure 1 shows a standard lens that will yield unwanted pooling at the base of the cone and peripheral bearing that can seal off and cause corneal problems. Figure 2 demonstrates the benefits of a smaller optical zone to fit the cone contour. The design results in little tear pooling at the base of the cone and shows an even distribution of tears under the lens.
- 7. Types of RoseKlens ROSE K2 lens with front surface aberration control providing superior vision. ROSEK2 Soft-Irregular corneas ROSE K2 Irregular Cornea (IC) lens for larger areas of corneal distortion. ROSE K2 Post Graft (PG) lens for post corneal surgical cases. ROSE K2 NC lens specifically for nipple cones. ROSE K2XL corneo-scleral lens which is ideally suited for patients who cannot tolerate smaller GP corneal lenses, for pellucid marginal degeneration, keratoglobus, corneal inserts, and patients who have significant corneal distortion after undergoing penetrating keratoplasty.
- 8. Indications Rose KSoft: New contact lens wearers with irregular corneas, early to moderate irregular corneas, if acuity with conventional soft lenses is unsatisfactory Rose K2 KC: Oval keratoconus Secondary Indication: Early nipple cones Rose K2 NC : Nipple cones Secondary Indication: Advanced oval cones Rose K2 PG: Post Graft corneas Decentered large oval cones Rose K2 IC: post corneal surgery, e.g. LASIK & PK Primary Indication: Pellucid Marginal Degeneration Keratoglobus LASIK induced ectasia Post Graft Secondary Indication: Highly decentered oval cones
- 9. Corneal BC assessment-Topo When selecting the initial base curve, keratometer only measures the central 3 mm along the line of sight, so your first trial lens may not yield the best fit. Determine the appropriate ROSE K2 design for the corneal condition to be treated.
- 10.
- 11. Flexible Edge LiftSystem With ROSE K2 use either the standard edge, standard flat or standard steep edge lift to achieve the desired peripheral fit. 0.1 increments ranging from -1.3 decreased to +3.0 increased ROSE K2 NC very rapid peripheral flattening standard edge lift, standard flat or standard steep. 0.1 increments ranging from -1.5 decreased to +4.0 increased ROSE K2 IC and ROSE K2 PG lenses standard edge lift (0), standard flat /increased (+1.0), double flat (+2.0), standard steep/decreased (-1.0) or double steep (-2.0) for optimum peripheral fit. 0.5 increments ranging from -3.0 decreased to +3.0 increased
- 13. ACT By nature,the keratoconus cornea is asymmetric, where the inferior quadrant is frequently significantly steeper than the superior portion, causing the GP lens to lift off at 6 o’clock ROSE K2 lenses incorporating ACT are designed to accommodate this asymmetry (good edge fit at 3, 9 and 12 o’clock but lift at 6 o’clock). The inferior quadrant of the lens is steepened, providing a more accurate fit at 6 o’clock making the lens more comfortable and stable and often providing superior vision. ACT is independent of the primary base curve and edge lift and can be added to any Rose K design in up to 2 quadrants at any axis.
- 15. Availability The 3and 9 o’clock meridians are flattened while the 6 and 12 o’clock meridians are steepened. Other values are available in 0.1 steps between 0.4 mm and 2.6 mm ROSE K2 and in 0.1 steps between 0.4 mm and 2.0 mm for ROSE K2 NC, PG & IC designs
- 17.
- 18. TORIC PERIPHERAL CURVES A toric periphery (TP) is where the optical zone is spherical and approximately the last 1 mm of the peripheral curve. With Keratoconus, the tight areas 3 and 9 o’clock In PMD there is often significant against-the-rule astigmatism making the lens tight at 12 and 6 o’clock and loose at 3 and 9 o’clock. A lens that is tight at 12 o’clock causes discomfort, so a TP design is often useful here. The TP design is available on ROSE K2, ROSE K2 NC, ROSE K2 IC, ROSE K2 PG enhance lens fit, stability, comfort, vision and wearing time.
- 19.
- 20. Fitting steps Basecure Central fit Peripheral fit Diameter Location Movement Power
- 22. Central fit: Thelens will continue to settle onto the cornea the longer on its on the eye Minimum 60 sec Straight ahead gaze Make sure Lens centrally placed over the pupil Evaluate fluorescence immediately after blink
- 25. Step 2: PeripheralFit Once optimum central fit is achieved, assess edge lift. Look for an even fluorescein band of 0.5 mm to 0.7 mm in width For asymmetric edge lift where the lift is excessive in one meridian and insufficient in the other meridian, consider toric peripheral curves For significant edge stand off/lift off in one quadrant only, consider ACT. Quadrant specific lifts are also available where a different lift can be ordered in each quadrant.
- 29. Step 3: Diameter Minimum diameter that yields good location and movement. Lens should hang off top lid and be well clear of lower limbus(K2,NC) Lens should show good attachment under the top lid and be well clear of the lower limbus(PG,IC) Smaller diameters for central Smaller; steeper cones advanced KC and larger diameters for decentered cones, early KC, large areas of corneal disortion Flatter nipple cones
- 30. Continued…. Increasing diameterwill help lens location/centration. Make sure lens is not impinging on upper sclera. (PG,IC)
- 33. Step4: Location ToImprove Location: Lens resting too low (inferior): flattening BC, increasing edge lift and increasing diameter. Lens resting too high (superior): steepening BC decreasing edge lift decreasing diameter
- 35. Step 5: Movement Must achieve tear exchange Movement on blink should be 1.0 to 1.5 mm Controlled by edge lift To increase movement, increase edge lift, decrease diameter and/or flatten base curve. To decrease movement, decrease edge lift, increase diameter and/or steepen base curve.
- 36. Step6: Power Assessment Residual Astigmatism (RA): It is common to leave low amounts of R.A. uncorrected, or to compensate spherically Spherical compensation of R.A. -0.25 to -0.50: add -0.25 D R.A. -0.75 to -1.00: add -0.50 D
- 37.
- 38. Assessment- Static Fit RoseK Soft RoseK NC RoseK PG RoseK IC RoseK XL
- 39. Static Fit-RoseK soft Daily wear for irregular corneas 3 month replacement -silicone hydrogel materials and a 6 or 12months - hydrogel materials Lagado Silicone Hydrogel : Water content 49%, Dk 49, handling tint Menicon Soft 72 Hydrogel: Water content 72%, Dk 34, handling tint • Available in single vials for hydrogel and silicone hydrogel lenses and a 2-pack for silicone hydrogel. Primary indications: Intolerance to GP lenses, new contact lens wearers with irregular corneas, early to moderate irregular corneas, if acuity with conventional soft lenses is unsatisfactory, environment is unsuitable for GP wear, GP lens may be unstable, e.g. sport. Contraindications: ocular pathology or when satisfactory acuity cannot be attained with best sphero-cylinder correction or a pinhole.
- 40. Base curve selection Keratoconus and Corneal inserts: Select a lens 0.80mm to 1.00mm flatter than mean Ks or mean 3mm Sim Ks. Corneal Grafts, PMD and LASIK: Select a lens with a BC equal to the mean Ks or 3mm Sim Ks
- 41. Step 2& 3:Peripheral Fit& Diameter Five peripheral fit options are available: Standard, Standard Increased and Double Increased (to loosen the fit) or Standard Decreased and Double Decreased (to tighten the fit). For smaller/larger HVID’s, decrease the diameter to achieve 1.5mm outside the limbus. If the lens causes any significant scleral indentation, go smaller (and/or increase the edge lift)
- 42. Step 4:Location Thelens should not locate down significantly on upward gaze. The laser mark should locate within 20 degrees of 6 o’clock. To improve location: a. Steepen the base curve. b. Increase the diameter. c. Decrease the edge lift.
- 43. Step 5: Movement On blink, approximately 1.0mm of movement should be observed. To increase movement, increase the edge lift, decrease the diameter and/or flatten the base curve. To decrease movement, decrease the edge lift, increase the diameter and/or steepen the base curve
- 44. ACT: Asymmetric CornealTechnology flute at the edge. This will usually occur in the lower half between 4 o’clock and 8 o’clock, even though the rest of the fit may appear ideal.
- 45. Lens care bothhydrogen peroxide and multi-purpose lens care regimens When opting for a multi-purpose system, Menicon recommends MeniCare Soft or SOLOCARE AQUA®
- 46. Static Fit- RoseKNC Central Fit Evaluation Peripheral Fit
- 47. Location Lens location- good pupil coverage. Low locating lenses can be encouraged to ride up by flattening the BOZR, increasing the Edge Lift and/or increasing total lens diameter. To correct high locating lenses, the BOZR can be steepened, the Edge Lift decreased, and/or the total lens diameter decreased.
- 48. RoseK IC CentralFit: a light central touch is the goal A slightly flatter fit is more desirable then a steeper fit as the central touch is spread over a larger area and the cornea does not erode as much in normal keratoconus
- 49. Peripheral Fit width atthe edge of lens will be 0.5mm to 0.7mm. This may not be uniform around the whole diameter of the lens, but it should not display excessive lift off or excessive sealing in any one area
- 50. RoseK: PG BostonMaterial non UV MeniconZ Material with a DK 163/SO BC: 0.3mm steeper than average K Dia: Commonly choose 10.4 mm trial lens
- 52. Central & Peripheralfit Central: 0.2 to 0.3 mm in early flatter grafts where the donor tissue is flatter than host tissue Peripheral: 0.5to 0.7 mm edge width Edge lift if excessive at 12 & 6 o clock ; insufficient at 3& 9 o clock consider toric PCs Location: if lens decentres in any location increase the Dia 0.5mm
- 53. Central fit touchat highest point
- 55. RoseK2 XL SemiScleral Lens Indication: K’conus, PMD, PG, Post LASIK, ectasia, RGP intolerance, irregular corneal condition not successful within the fitted limbus Sec.Indication: Polluted work condition stability, for sport, piggyback subsititute Front Surface Toric (FST) Toric Periphery (TP) Quadrant Specific Edge Lift (QSEL) Asymmetric Corneal Technology (ACT) Segment Specific ACT (SSACT) Bifocal for presbyopia
- 57.
- 58. Peripheral fit Aperipheral fluorescein band with a minimum width of 0.8 to 1.0 mm must be observed(fig 1) If the fluorescence under the lens is ideal but the band of fluorescein is too wide, decrease the diameter If the fluorescence under the lens is ideal but the band of fluorescein is too narrow increase the diameter If the edge lift is excessive the lens the fluorescein band will show dense fluorescence and may be too wide. The edge of the lens may lift off from the conjunctiva and cause subsequent bubbling under the edge of the lens. DECREASE THE EDGE LIFT If the edge lift is inadequate but insufficient fluorescein or no fluorescein will be seen under the edge of the lens outside the limbus. INCREASE THE EDGE LIFT
- 60.
- 61. Diameter The edge ofthe lens should extend to approximately 1.3 to 1.5 mm beyond the limbus Recommended standard diameter: 14.60 mm (60% of fits) • On the average sized cornea of 11.8 mm, the lens should extend 1.3 to 1.5 mm outside the limbus • For large corneas, increase the diameter to achieve 1.3 to 1.5 mm outside the limbus • For small corneas, decrease the diameter to achieve 1.3 to 1.5 mm outside the limbus
- 62. Location Objective: Thelens should sit evenly around the limbus A decentered apex may cause the lens to locate inferiorly To improve location, increase the diameter and/or flatten the BC Slight decentration may not cause any major issues but may be slightly less comfortable
- 63. Movement Objective: Onfirst insertion, the lens should move about 0.5 to 1.0 mm on blinking To decrease the movement: Decrease the edge lift, flatten the BC or use a combination of both To increase the movement: Increase the edge lift, steepen the BC or use a combination of both
- 65. Lens insertion Placethe lens concave side up, onto a large plunger Fill the lens with non-preserved saline solution and add a small amount of fluorescein head down, so it is parallel with the floor, and centrally apply the lens directly onto the cornea so the solution remains in the lens a suction holder or by balancing the lens in a tripod between the thumb, index and middle finger
- 66. Lens removal Placea small solid wetted plunger between the outside of the lens and the temporal pupil margin Peel the lens off by pulling outwards and across in an arc towards the nose or by using the lower lid to lift the lower contact lens edge up and outwards
- 67.