Is there a difference in fitting time for spherical and toric soft contact lenses?

Authors:
Anna Sulley¹, Rachel Marullo², Michel Guillon³, Pasquale Pepe³, Percy Lazon de la Jara²
1 CooperVision International Ltd, UK
2 Coopervision, Inc., USA
3 Ocular Technology Group International, UK
 

Purpose 
Concerns that fitting soft toric contact lenses requires longer chair time than their spherical counterparts remains a concern.  Two studies that assessed the performance of spherical and toric lenses measured the time required to finalise their prescription and carry out the overall fit.
 

Methods 
Two interventional, prospective, open-label, investigator-masked studies compared fitting times of stenfilcon A spherical and toric contact lenses. One study followed a parallel design comparing the time to determine the prescription for stenfilcon A spherical contact lenses for current spherical wearers with that of stenfilcon A toric contact lenses for current toric wearers. The other study followed a crossover design comparing the overall fitting time (prescription and physical fit) of low astigmatic contact lens wearers fitted with both  spherical and toric stenfilcon A.  Linear mixed model analyses were performed for both studies.
 

Results
Time to determine the contact lens’ final prescription was similar for the two lens types  (mean: sphere: 469 secs; toric: 396 secs, p=0.324, n=40) associated with both similar spectacle refraction time (mean: sphere: 247 secs; toric: 188 secs, p=0.0.244) and over-refraction (mean: sphere: 222 secs; toric: 208 secs, p=0.678) for both lens types. The overall fitting time was also similar for the two lens types (mean: sphere: 523 secs; toric: 788 secs, p=0.133, n=24) associated with similar baseline spectacle refraction time for the two contact lenses (mean: sphere: 275 secs; toric: 384 secs, p=0.280) and similar physical fitting time (mean: sphere: 84 secs; toric: 257secs, p=0.100)
 

Conclusions
Spherical and toric stenfilcon A contact lenses required similar fitting time, allaying concerns that toric soft contact lenses require longer chair time.
 

Disclosures
Study was carried out by Ocular Technology Group International financially supported by CooperVision, Inc.
Anna Sulley, Rachel Marullo and Percy Lazon de la Jara are employees of CooperVision.