Summary of the September 1999 Session "Bifocal GPs," with Richard Baker, OD and David Hansen, OD

Please note that the ideas presented during the chat are those of the participating eyecare professionals. They do not necessarily represent the views of the moderator or guest expert, and are not endorsed by the GP Lens Institute.

• Due to the preponderance of computer users, most patients could benefit from an aspheric bifocal design.
   
• Translating designs are best for those with astigmatism, and monovision for those aged 40-44.
   
• Dr. Hansen uses aspherics even for high adds, and has several labs who add plus to the front surface to enhance the higher add.
   
• Some good aspherics for high adds include the VFL-3, Essential, and EZ Bifocal.
   
• For emmetropic presbyopes some prefer translating designs. Dr. Baker starts with monovision then moves to modified monovision using an aspheric design.
   
• Emmetropic presbyopes are a growing problem.
   
• Some labs are not cutting ST bifocals as thin as in the past; this has caused some refitting problems.
   
• Poor tear quality and quantity often complicate bifocal fittings and must be addressed if the fit is to be successful. Punctal plugs may be useful in these cases.
   
• Some fitters believe hormone replacement therapy to play a role by reducing tear quantity.
   
• The Mandell Seamless bifocal shows great promise (Dr. Baker).
   
• Dr. Hansen has had good luck fitting aspheric bifocals on young progressive myopes — he sees very little change after they've begun wearing GP bifocals.
   
• Dr. Hansen also believes that if the autorefractor & retinoscopy demonstrate more myopia than the subjective by .75D, then the patient is truly a progressive myope.
   
• For hyperopes try to go with a larger overall diameter to improve stability.
   
• A high Dk FSA is the preferred material for hyperopes and high myopes.
   
• An aspheric design is also preferred for high Rxs to reduce thickness.
   
• Several "typical" cases were presented to the group and the options discussed. As usual, there was no consensus on the best lens!