C Franz

Long-term results of implantation of phakic posterior chamber intraocular lenses

Purpose: To study the incidence and progression of lens opacification after implantation of phakic posterior chamber intraocular lenses for myopia and its correlation with vaulting and endothelial cell density (ECD). Setting: Department of Ophthalmology, University of Vienna Medical School, Vienna, Austria. Methods: An implantable contact lens (ICL V4, Staar Surgical Inc.) was inserted in 76 myopic eyes. Patients were prospectively followed preoperatively and at 1, 3, 6, 12, 24, and 36 months. The uncorrected visual acuity and best corrected visual acuity (BCVA) were determined. Vaulting was measured optically with a Jaeger II pachymeter, and the crystalline lens was examined at the slitlamp for the presence and characteristics of opacification. Endothelial cell morphometry was performed by specular microscopy, and the ECD was calculated. Eyes in which lens opacification developed were followed for at least 12 months to determine the degree and course of visual impairment. Results: Lens opacification occurred in 11 eyes (14.5%). Opacification was correlated with intraoperative trauma to the crystalline lens, age older than 50 years, and decreased ECD values throughout the observation period. Vaulting of the ICL did not correlate with the risk for lens opacification. After onset of lens opacification, 6 eyes (55%) had a stable BCVA within ±0.5 lines and 5 eyes had progressive opacification, losing between 3.5 lines and 0.5 lines (mean 1.8 lines ± 1.1 [SD]). Three eyes (3.9%) in the progressive group had a 1‐ to 2‐line loss of BCVA over preoperative values and subsequently had cataract surgery. Conclusions: Risk factors for lens opacification after implantation of the model V4 ICL included intraoperative trauma to the crystalline lens and older age. Decreased ECD in eyes with opacification suggests ongoing inflammation as a cause. Patients younger than 45 years may have a significantly lower incidence of opacification.

Influence of spectacle-related changes in retinal image size on contrast sensitivity function after laser in situ keratomileusis.

Purpose: To evaluate changes in contrast sensitivity after laser in situ keratomileusis (LASIK) for the correction of myopia using a monitor‐based method and considering the preoperative minification effect of high‐diopter spectacles. Setting: Department of Ophthalmology, University of Vienna Medical School, Vienna, Austria. Methods: Fifteen eyes of 11 patients had LASIK to correct myopia. The best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) were measured preoperatively and 1, 3, and 6 months postoperatively using the AcuityMax (Science 2020) computer program. The error in contrast sensitivity measurement due to different angular sizes of the test figures deriving from the spectacle refractions before and after LASIK were considered. Results: Preoperatively, and at 1, 3, and 6 months, the mean Snellen BCVA was 0.93 ± 0.19 (SD), 0.80 ± 0.26, 0.85 ± 0.21, and 0.84 ± 0.27, respectively. The best mean CS (measured at 1.1 logMAR) was 1.17 ± 0.05, 1.12 ± 0.07, 1.13 ± 0.08, and 1.18 ± 0.04, respectively. The strongest CS changes were observed at 0.7 logMAR (6 cycles per degree), where CS was 1.10 ± 0.07 preoperatively and 1.06 ± 0.09, 1.07 ± 0.12, and 1.14 ± 0.07, at 1 month, 3 months, and 6 months, respectively. With correction for the spectacle effect, the preoperative CS was approximately 3% higher and CS at 3 months for intermediate optotype sizes was significantly inferior to preoperatively. Conclusions: With correction of different retinal image sizes before and after LASIK (due to different spectacle refraction), the CS was significantly below the preoperative values at 1 and 3 months and approached the preoperative values at 6 months. The proposed method is potentially capable of quality monitoring and method comparisons after photorefractive surgery.