A theoretical model for comparing UK costs of contact lens replacement modalities.

PURPOSE: To develop a theoretical 'cost-per-wear' model of contact lens wear, as tool for UK practitioners to assist patients in determining the most cost-effective lens replacement and wearing frequency protocols. METHODS: The annual cost of professional fees, contact lenses and solutions when wearing daily, two weekly and monthly replacement contact lenses was determined for spherical, toric and multifocal prescription types. This annual cost was divided by the number times lenses are worn per year, resulting in a cost-per-wear. RESULTS: The cost-per-wear for two weekly and monthly replacement contact lenses is similar, both decreasing with increasing frequency of wear. The cost-per-wear of daily replacement lenses is lower than for reusable lenses when worn 1-2 days per week (DPW), but higher when worn 4-7 DPW. The 'cross-over point' for spherical lenses at which the cost-per-wear is virtually the same for the three replacement frequencies, approximately £2.06, occurs at 3 DPW. The cross-over point for toric lenses is at 4 DPW with daily compared to two weekly replacement lenses (£2.06) and between 2-3 DPW with daily compared to monthly replacement contact lenses (£2.39). The crossover point for multifocal lenses of all replacement frequencies is between 4 and 5 DPW (£1.79). CONCLUSIONS: In general, daily replacement contact lenses are more cost-effective when worn on a part-time basis (1-3 DPW) and reusable lenses are more cost-effective when worn full-time (4-7 DPW). This cost-per-wear model will assist practitioners in making an informed decision when offering advice to patients relating to the most suitable replacement modality.

A 'cost-per-wear' model based on contact lens replacement frequency.

PURPOSE: The aim was to construct and advise on the use of a cost-per-wear model based on contact lens replacement frequency, to form an equitable basis for cost comparison. METHODS: The annual cost of professional fees, contact lenses and solutions when wearing daily, two-weekly and monthly replacement contact lenses is determined in the context of the Australian market for spherical, toric and multifocal prescription types. This annual cost is divided by the number of times lenses are worn per year, resulting in a 'cost-per-wear'. The model is presented graphically as the cost-per-wear versus the number of times lenses are worn each week for daily replacement and reusable (two-weekly and monthly replacement) lenses. RESULTS: The cost-per-wear for two-weekly and monthly replacement spherical lenses is almost identical but decreases with increasing frequency of wear. The cost-per-wear of daily replacement spherical lenses is lower than for reusable spherical lenses, when worn from one to four days per week but higher when worn six or seven days per week. The point at which the cost-per-wear is virtually the same for all three spherical lens replacement frequencies (approximately AUD$3.00) is five days of lens wear per week. A similar but upwardly displaced (higher cost) pattern is observed for toric lenses, with the cross-over point occurring between three and four days of wear per week (AUD$4.80). Multifocal lenses have the highest price, with cross-over points for daily versus two-weekly replacement lenses at between four and five days of wear per week (AUD$5.00) and for daily versus monthly replacement lenses at three days per week (AUD$5.50). CONCLUSIONS: This cost-per-wear model can be used to assist practitioners and patients in making an informed decision in relation to the cost of contact lens wear as one of many considerations that must be taken into account when deciding on the most suitable lens replacement modality.

Inefficacy of aspheric soft contact lenses for the correction of low levels of astigmatism.

PURPOSE: The purpose of this article is to compare the visual performance of a toric soft (TS) contact lens (SofLens 66 Toric; Bausch & Lomb, Rochester, NY), an aspheric soft (AS) contact lens (Frequency Aspheric; CooperVision, Fairport, NY) and a spectacle correction (SC) in subjects with low levels of astigmatism. METHODS: One eye of 30 subjects with refractive astigmatism of -0.75 DC or -1.00 DC was tested. After pupil dilation, each subject was fitted with all three forms of correction in random order. Subjects were masked from the contact lens type. High-contrast visual acuity (HCVA) and low-contrast visual acuity (LCVA) were recorded for each correction using 2-mm, 4-mm, and 6-mm artificial pupils. RESULTS: With a 2-mm pupil, HCVA was similar for the TS lens and the SC (p = 0.13); better HCVA was demonstrated with the TS lens than with the AS lens (p = 0.001). With 4-mm and 6-mm pupils, HCVA was poorer with the AS lens than with the SC (p < 0.002) and TS lenses (p < 0.0001). The difference in HCVA between the TS and AS lenses was two letters, three letters, and one line with pupil sizes of 2 mm, 4 mm, and 6 mm, respectively. LCVA was similar for the three refractive conditions with the 2-mm pupil size. With 4-mm and 6-mm pupils, LCVA was similar for the TS lens and SC, but better than the AS lens by approximately one line in each case (all p < 0.0001). CONCLUSIONS: For small pupil sizes, there is little difference in HCVA and LCVA between various refractive corrections. However, for larger pupils, HCVA and LCVA are superior with TS contact lenses and SC versus AS contact lenses by approximately a half-line or more, which is considered to be clinically significant. Superior vision can be achieved for low astigmatic contact lens wearers using TS rather than AS contact lenses.