Effectiveness of toric soft contact lenses for vision correction in patients with different degrees of astigmatism: a real-world study

AIM:To assess the visual correction of patients with different degrees of astigmatism with toric soft contact lenses(TSC).METHODS:It was a real-world study with prospective and single-arm design.A total of 384 patients with astigmatism who came for TSC fitting and alignment from November 2022 to January 2023 were included.According to the difference in astigmatism,patients were divided into groups A(cylinder degree:-0.75 to-0.50 D),B(cylinder degree:-1.75 to-1.00 D)and C(cylinder degree≤-2.00 D),and followed up on the day of wear,1wk,1 and 3mo,mainly to observe visual acuity,refraction,lens fit,visual quality and comfort at 1wk after wear.The visual acuity success rate and the overall success rate of the fitting were evaluation indicators(taking into account the four dimensions of visual acuity,fitting,quality of vision and comfort).The visual acuity success rate was calculated by taking“corrected visual acuity with contact lenses is no less than 1 line or better than best spectacle-corrected visual acuity”(i.e.corrected visual acuity with contact lenses is 1 line below,equal to,one line above or more than best spectaclecorrected visual acuity)as the criterion for visual success,and the the overall success rate of the fitting was calculated by using the comprehensive indicators(visual acuity,fit,visual quality,comfort)to meet certain conditions as the judgment criteria for successful fitting.RESULTS:After 1wk of wearing TSC,the visual acuity success rates of patients were 100%(207/207),98.58%(139/141)and 97.22%(35/36)in the three groups,respectively,with residual cylinder closed to 0.The acceptability of the lens fitting was over 95%;the incidence of adverse visual symptoms was within 10%and the comfort acceptability was over 97%.The overall success rate of fitting for patients with high,medium and low astigmatism was 93.72%(194/207),90.78%(128/141)and 88.89%(32/36),respectively.CONCLUSION:TSC(model:G&G POP·CT)are effective in correcting astigmatism in patients with different degrees of astigmatism.

Does offering only the spherical contact lens trial to the low astigmats mislead the practitioners?

AIM:To compare the visual acuity(VA),comfort,and patient preference in a soft toric contact lens(TCL)versus soft spherical contact lens(SCL)in low astigmatic subjects during the contact lens(CL)trial.METHODS:This subject-masked,block randomized,2×2 crossover study recruited 40 neophyte subjects(80 eyes)aged 18 to 33 y with astigmatism in the range of 0.75-1.25 D with or without spherical power from-6.00 D to+6.00 D.The participants were scheduled for two days CL trial and were fitted with the best-fit SCL and TCL.After 4 h of wear,they were assessed objectively for high contrast VA and subjective vision,comfort,and preference.RESULTS:The responses of 36 subjects(response rate 90%)with a mean age of 23.02±2.97 y(range 18 to 33 y)were analyzed.One-line improvement of monocular VA in the logMAR chart was reported to TCL as compared to SCL(-0.044±0.06 vs 0.04±0.03 logMAR,P=0.01)but the binocular vision remained similar(-0.12±0.07 vs-0.14±0.04 logMAR,P=0.38).Subjects felt a noticeable difference in clarity when shifted to TCL as compared to the SCL.The satisfaction with vision(vision quality)was significantly better with TCL(P=0.03).The fatigue with TCL was graded less at 2.5±0.6,compared to SCL at 4.6±1.3(P=0.04).Thirty-three participants(91.6%)preferred to use contact lens of which 26 participants(79%)preferred TCL.CONCLUSION:The findings suggest that VA and comfort are better with TCL as compared to SCL which is only observed if the patient was offered both offering SCL with spherical equivalent power alone as the first option can mislead the practitioner;TCL trial should be the first choice of the lens in low-to-moderate astigmatism.