HydroCone

Description

HydroCone 12: keratoconus of degrees 1 to 2

HydroCone 34: keratoconus of degrees 3 to 4

HydroCone P:Multifocal-variants of HydroCone 12 and 34 with front optic zone in Bifocal (Bf) / Simple progressive (Sp) / Multi progressive (Mp)

Parameter	from	to	steps
Total diameter	12.00 mm	15.00 mm	0.01 mm
Base curve	7.00 mm	12.00 mm	0.01 mm
Sphere	-40.00 dpt	+40.00 dpt	0.01 dpt
Cylinder	-0.25 dpt	-8.00 dpt	0.01 dpt
Axe	0°	180°	1°
Addition	+0.50 dpt	+4.00 dpt	0.01 dpt
Central optical zone Zoc	1.00 mm	5.50 mm	0.01 mm
Flattening	(+) K12	(++) K34

Application	Distance vision, Presbyopia
Indication	Keratoconus
Correction type	Myopia, Hyperopia, Astigmatism
Lens Type	Soft
Designed by	SwissLens

We suggest working with trial lenses with cyl −0.01 dpt.

First apply the topographic indications or the following rules:

The first trial lens helps to validate BC / ØT.
Dynamic stabilisation marks are needed to measure the stabilisation axis
The power (F’v) is spherical because part of the correction is made by the tear film and can’t be anticipated. The final cylinder corresponds to the residual astigmatism.
F’v for the trial lens order: spectacle sphere (adjust BVD = 0) with −0.01 dpt × 180° cylinder
For changes and control over several months always use the initial (genesis) lens for over refraction.
Use upper and lower eyelids to remove the contact lens.
By halo, increase optic zone diameter
Measurement of the residual astigmatism with autorefractometer plus subjective refractometry.
Due to geometry, the contact lens can slip a little bit to the bottom.
Increasing centre thickness can improve the visual acuity.
HydroCone P fitting: initially fit with HydroCone (single vision toric lens) then add progression in a second step BC

Centre near vision in most cases
Peripheral near vision if distance vision is poor, high myopia or decentrated pupil.

Determine dominant eye
Find maximum convex (+) correction for distance vision
Find the best acuity in distance vision to optimise Zoc diameter choice
Determine the patients needs for: distance / intermediate / near Multifocal design choice

Requirements	Bifocal Bf	Simple progressive Sp	Multi progressive Mp
Hyperopia			√
Myopia Addition < 1.75 dpt	√
Myopia: Addition ≥ 1.75 dpt		√
Priority in distance vision	√	√
Priority in near vision	√		√
Priority in intermediate vision (computer)			√
Use in low light in distance vision		√
Use in low light in near vision			√
Good contrast	√		√
Low Helos		√
Anisometropia > 2.00 dpt	√	√
Amblyopia	√	( √ )
Modified monovision care	( √ )	√

recommendations for the 1st choice: standard pupil (3.50–4.00 mm) with normal lighting

	Bifocal Bf	Bifocal Bf	Simple progressive Sp	Simple progressive Sp	Multi progressive Mp
Position	Centre near (CN)	Centre Distance (CD)	Centre near (CN)	Centre Distance (CD)	Centre near (CN)
Dominant eye	2.25	3.75	2.50	4.00	1.50
Non-dominant eye	2.75	3.25	3.00	3.50	1.75
Undefined	2.50	3.50	2.75	3.75	1.50