Comparison of contrast sensitivity after angle-supported, iris-fixated and posterior chamber phakic intraocular lens implantation for high myopia.
OBJECTIVE
To evaluate the effects of angle-supported, iris-fixated and posterior chamber phakic intraocular lens (PIOL) implantation on contrast sensitivity (CS).


METHODS
This prospective study included 69 eyes of 41 consecutive cases of high myopia which received an angle-supported (Phakic-6H; 26 eyes), iris-fixated (Verisyse; 23 eyes) or posterior chamber PIOL [phakic refractive lens (PRL); 20 eyes]. Photopic, mesopic and mesopic with glare CS were evaluated preoperatively and at least 6 months postoperatively.


RESULTS
In the PRL group, the mean postoperative CS at all frequencies and across all lighting conditions increased. These changes were significant for 6, 12 and 18 cycles per degree (cpd) under both photopic and mesopic conditions (p < 0.01) and for all the tested frequencies under mesopic with glare condition (p < or = 0.01). The average CS was relatively low in the PRL group. These changes were significant for 6 and 12 cpd between the Verisyse and PRL group under photopic condition (p < 0.05), for 3 and 6 cpd under mesopic condition (p < 0.01, p = 0.01) and under mesopic with glare condition (p < 0.01, p < 0.05).


CONCLUSIONS
Improvements in postoperative CS confirm that PIOL implantation is a promising alternative for correction of high myopia. In comparison to posterior chamber PIOLs, angle-supported and iris-fixated PIOLs seem to produce a better visual quality in terms of CS, which needs to be warranted by further investigations.
Yu
Ayong
A
Affiliated Eye Hospital at Wenzhou Medical College, Wenzhou, China.
Wang
Qinmei
Q
Xue
Anquan
A
Zhu
Shuangqian
S
Wang
Shulin
S
Chen
Yunyun
Y
Sun
Jin
J
D000328:Adult; D000867:Anterior Chamber / Q000601:surgery*; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D019466:Glare; D006801:Humans; D007498:Iris / Q000601:surgery*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D054120:Phakic Intraocular Lenses; D011183:Postoperative Complications / Q000503:physiopathology; D011446:Prospective Studies; D011474:Prosthesis Design; D012029:Refraction, Ocular; D014792:Visual Acuity / Q000502:physiology