Ring-shaped dysphotopsia associated with posterior chamber phakic implantable collamer lenses with a central hole

• Main Authors: Eom, Youngsub, Kim, Dae Wook, Ryu, Dongok, Kim, Jun-Heon, Yang, Seul Ki, Song, Jong Suk, Kim, Sug-Whan, Kim, Hyo Myung
• Other Authors: Univ Arizona, Coll Opt Sci
• Language: en
• Published: WILEY 2017
• Subjects: central hole; dysphotopsia; posterior chamber phakic implantable collamer lenses
• Online Access: http://hdl.handle.net/10150/623614; http://arizona.openrepository.com/arizona/handle/10150/623614

Purpose: To evaluate the incidence of central hole-induced ring-shaped dysphotopsia after posterior chamber phakic implantable collamer lens (ICL) with central hole (hole ICL) implantation and to investigate the causes of central hole-induced dysphotopsia. MethodsThe clinical study enrolled 29 eyes of 15 consecutive myopic patients implanted with hole ICL. The incidence of ring-shaped dysphotopsia after hole ICL implantation was evaluated. In the experimental simulation study, non-sequential ray tracing was used to construct myopic human eye models with hole ICL and ICL without a central hole (conventional ICL). Simulated retinal images measured in log-scale irradiance were compared between the two ICLs for an extended Lambertian light-emitting disc object 20cm in diameter placed 2m from the corneal vertex. To investigate the causes of hole-induced dysphotopsia, a series of retinal images were simulated using point sources at infinity with well-defined field angles (0 to -20 degrees) and multiple ICL models. ResultsOf 29 eyes, 15 experienced ring-shaped dysphotopsia after hole ICL implantation. The simulation study using an extended Lambertian source showed that hole ICL-evoked ring-shaped dysphotopsia was formed at a retinal field angle of 40 degrees. Component-level analysis using a well-defined off-axis point source from infinity revealed that ring-shaped dysphotopsia was generated by stray light refraction from the inner wall of the hole and the posterior ICL surface. ConclusionHole ICL-evoked ring-shaped dysphotopsia was related to light refraction at the central hole structure. Surgeons are advised to explain to patients the possibility of ring-shaped dysphotopsia after hole ICL implantation.