Correction of high myopia with the PRL phakic intraocular lens

PURPOSE: To assess the predictability, efficacy, safety, and complications of the PRL (CIBA Vision) phakic intraocular lens (pIOL) in the correction of high myopia. SETTING: Clínica Oftalmológica Pasteur, Santiago, Chile. METHODS: This prospective study comprised 53 eyes of 39 patients who received a PRL pIOL. The spherical equivalent (SE), uncorrected visual acuity (UCVA), efficacy index (postoperative UCVA/preoperative best spectacle-corrected visual acuity [BSCVA]), safety index (BSCVA/preoperative BSCVA), intraocular pressure (IOP), iridocorneal angle, and distance between the crystalline lens and PRL were prospectively assessed during the follow-up period. RESULTS: The mean patient age was 39 years. The mean power of the implanted pIOL was -12.73 diopters (D) +/- 2.87 (SD) (range -20.00 to -7.00 D), for a preoperative SE of -17.27 +/- 4.58 D (range -31.50 to -8.75 D). The mean preoperative BSCVA was 0.50 +/- 0.70 (logMAR equivalent), and the mean follow-up was 8 +/- 9.4 months. The mean postoperative SE was -0.23 +/- 1.05 D; 71.2% of eyes were within +/-1.00 D. Sixty percent of patients had UCVA of 20/40 or better, and 88.2% of patients had BSCVA of 20/40 or better. Ninety-two percent maintained or gained 1 or more lines of BSCVA; 5.7% lost more than 1 line. There was no significant change in IOP (P = .40), and the mean distance between the crystalline lens and pIOL was 370 microm (ultrasound) and 604 microm (optical coherence tomography). Late complications included 1 case each of retinal detachment and lens subluxation. CONCLUSIONS: Although PRL implantation in high myopia was predictable and effective, retinal detachment and IOL subluxations occurred. Other posterior chamber pIOLs should be used until the complications associated with the PRL pIOL are resolved.     

Scheimpflug photographic imaging following implantation of anterior and posterior chamber phakic intraocular lenses: preliminary results

BACKGROUND: For the correction of refractive errors lenticular procedures are increasingly used in addition to corneal refractive surgery. One of those techniques is the implantation of intraocular lenses into phakic eyes (pIOL). Due to the close neighborhood of the implant to delicate intraocular structures, exact positioning and high postoperative stability are required. Scheimpflug photography has been shown to be a suitable instrument for the biometry of the anterior eye segment and the examination of IOL position. PATIENTS AND METHODS: Four anterior chamber phakic IOLs (pIOLs) (Bausch & Lomb NuVita) and 7 posterior chamber pIOLs (Staar ICL) were examined 1 week, 1 month and 3-6 months following implantation. At each examination 1 Scheimpflug slit image and 1 infrared retroillumination image were taken using the anterior eye segment analysis system EAS-1000 (Nidek Co., Gamagori, Japan). Evaluation of the images was performed with a personal computer and the software provided by the manufacturer. The distance of the pIOL to cornea and human lens was calculated and incidence and amount of pIOL rotation around the optical axis and potential crystalline lens opacification were assessed. RESULTS: The distance between the anterior chamber pIOL and the cornea 1 week after implantation was 1.61 +/- 0.10 mm. The distances between the myopic posterior chamber pIOL and the human lens were 0.34 +/- 0.11 mm and between the hyperopic posterior chamber pIOL and the human lens 0.26 and 0.29 mm, respectively. The values were constant over a period of 3-6 months. The pIOL showed no movement or change of position around the optical axis. There was no detectable cataract formation in the human lens. CONCLUSIONS: All implanted phakic anterior and posterior chamber IOLs showed a stable position in the eye within the observation period. Scheimpflug photography is proved to be a useful technique for the postoperative evaluation of the positioning of phakic IOLs.     

Phakic intraocular lenses: part 2: results and complications

The second part of a review of phakic intraocular lenses (pIOLs) addresses results and complications with current pIOL models. Phakic IOLs demonstrate reversibility, high optical quality, potential gain in visual acuity in myopic patients due to retinal magnification; correction is not limited by corneal thickness or topography. With proper anatomical conditions, pIOLs also show good results in hyperopic patients. Toric pIOL designs enable spherocylindrical correction. Complications are rare and primarily related to pIOL position and type. The main complications of angle-supported anterior chamber pIOLs are glare and halos, pupil ovalization, and corneal endothelial cell loss; of iris-fixated anterior chamber pIOLs, chronic subclinical inflammation, corneal endothelial cell loss, and dislocation or pupillary block glaucoma; and of posterior chamber pIOLs, anterior subcapsular cataract formation, pigment dispersion, and luxation or pupillary block glaucoma. No causative relationship between pIOL implantation (of any pIOL type) and retinal detachment has been established.     

白内障超声乳化治疗闭角型青光眼的疗效

目的：评价白内障超声乳化联合人工晶状体植入治疗闭角型青光眼的适应证及临床效果。 方法：回顾性分析合并有白内障的首发急性闭角型青光眼,且房角关闭粘连范围<180°的患者16例18眼,单纯行白内障超声乳化联合人工晶状体植入手术,观察分析术前和术后眼压、前房深度、前房角及矫正视力的变化。 结果：术后眼压全部控制在20mmHg（1mmHg=0.133kPa)以下,前房深度明显增加,17眼最佳矫正视力均有不同程度的提高,1眼无变化。术中、术后无严重手术并发症。术后随访期间,17眼视力无明显变化,1眼因视网膜分支静脉阻塞引起眼底出血视力下降明显。术前和术后眼压、前房深度、最佳矫正视力差异有统计学意义（P<0.05）。 结论：恰当适应证的选择可使单纯超声乳化白内障治疗闭角型青光眼获得满意的临床效果。     

小切口白内障手术治疗闭角型青光眼探讨

目的 探讨小切口白内障手术治疗急性闭角型青光眼的疗效.方法 回顾性分析合并有白内障的首发急性闭角型青光眼,且前房角关闭粘连范围小于180°者36例(36只跟),单纯行小切口白内障手术联合后房型人工晶状体植入术,观察分析术前和术后眼压、前房深度、前房角及矫正视力的变化,术后随访1～12月.结果 术后1周,36只眼眼压全部控制在20mmHg(1mmHg=0.133kPa)以下,前房深度明显增加,前房角增宽,34只眼最佳矫正视力均有不同程度的提高,2只眼无变化.术中术后无严重手术并发症.随访35只眼,同术后1周相比,眼压全部无明显变化,1只眼视力因眼底出血而下降.术前术后眼压,前房深度及视力差异有统计学意义.结论 小切口白内障手术联合后房型人工晶状体植入术治疗合并有白内障,且前房角关闭粘连范围小于180°的首发急性闭角型青光眼,方法简单,经济,效果良好.     

白内障超声乳化联合房角分离术治疗闭角型青光眼

目的：分析白内障超声乳化吸出+人工晶状体植入联合房角分离术治疗闭角型青光眼的临床效果。

方法：回顾性分析合并有白内障的闭角型青光眼患者,且房角关闭粘连范围≤180°的患者46例56眼,行白内障超声乳化吸出+人工晶状体植入联合房角分离手术,观察分析术前和术后眼压、视力、前房深度、前房角的变化。

结果：术后眼压全部控制在21mmHg(1mmHg=0.133kPa)以下,最佳矫正视力均有不同程度的提高,前房深度明显增加,房角均有不同程度开放。术中、术后无严重手术并发症。术前和术后眼压、前房深度、最佳矫正视力差异有统计学意义(P<0.05)。

结论：选择对合适的闭角型青光眼合并白内障的患者施行白内障超声乳化联合房角分离手术能够获得满意的临床效果。     

New Management of Angle—closure Glaucoma by Phacoemulsification with Foldable Posterior Chamber Intraocular Lens Implantation

Objective: To investigate the management oi angle-closure glaucoma byphacoemulsification with foldable posterior chamber intraocular lens (PC-IOL)implantation.Design: Retrospective, noncontrolled interventional case series.Participants: In 36 eyes with angle-closure glaucoma (ACG) , there were 18 eyes withprimary acute angle-closure glaucoma (PACG) , 14 eyes with primary chronicangle-closure glaucoma (PCCG) , 3 eyes with secondary acute angle-closure glaucoma(SACG) and 1 eye with secondary chronic angle-closure glaucoma (SCCG).Intervention: Phacoemulsification with posterior chamber intraocular lens implantation.Main Outcome Measures: Postoperative visual acuity, IOP, axial anterior chamberdepth.Results: After a mean postoperative follow-up time of 8. 81±7. 45 months, intraocularpressure was reduced from a preoperative mean of 23. 81 ±17. 84 mmHg to apostoperative mean of 12. 54 4. 73 mmHg ( P =0. 001). Mean anterior chamber depthwas 1. 75 ± 0. 48 mm preoperatively and 2. 29 ?0. 38 mm postoperatively     

白内障超声乳化在闭角型青光眼中的应用

目的探讨白内障超声乳化吸除合并人工晶状体（intraocular lens，IOL）植入术对伴有白内障的闭角型青光眼的手术效果。方法对31例（33眼）闭角型青光眼伴白内障患者行白内障超声乳化吸除合并IOL植入术。观察手术前后前房角、前房深度、眼压及视力变化。术后随访1.5-3年。结果术后所有术眼眼压下降，平均（14.99±0.65）mmHg（1mmHg=0.133kPa），比术前用药后平均眼压（24.43±1.61）mmHg明显降低。手术前后眼压差异有显著性（t=5.28，P=0.000）。UBM检查中央前房深度，由术前的（1.60±0.25）mm增加到术后的（3.30±0.35）mm，两者差异有显著性（t=6.24，P=0.000）；术后前房角宽度均增加,房角开放。前房角镜检查前房角均增宽，睫状体带易于看见。术后视力明显提高（X^2=63.47，P〈0.01）。结论对由晶状体因素引起的瞳孔阻滞型闭角型青光眼合并白内障患者，白内障超声乳化吸除合并IOL植入术是可供选择的治疗方法之一。     

Severe endothelial cell loss following uneventful angle-supported phakic intraocular lens implantation for high myopia

Endothelial decompensation is a serious complication of phakic intraocular lens (pIOL) implantation and is a major concern during the postoperative period. We report 3 eyes in which the same foldable angle-supported pIOL was implanted to correct high myopia. Rapid and severe postoperative endothelial cell loss occurred in all 3 eyes. An over-sized pIOL that induced excessive vaulting into the anterior chamber was the main risk factor. In 2 eyes, the pIOL was explanted uneventfully; 1 eye required Descemet's stripping automated endothelial keratoplasty because of total endothelial decompensation. These cases illustrate the importance of accurate sizing of foldable angle-supported anterior chamber pIOLs to avoid excessive vaulting. They also highlight the importance of regular follow-up and preventive pIOL explantation as soon as significant endothelial cell loss is detected.     

Circumferential viscodilation and tensioning of Schlemm canal (canaloplasty) with temporal clear corneal phacoemulsification cataract surgery for open-angle glaucoma and visually significant cataract: one-year results

PURPOSE: To evaluate the safety and efficacy of circumferential viscodilation and tensioning of the inner wall of Schlemm canal, a new nonpenetrating surgical procedure (canaloplasty) to treat open-angle glaucoma (OAG), combined with clear corneal phacoemulsification and posterior chamber intraocular lens (IOL) implantation. SETTING: Multicenter surgical sites. METHODS: This international multicenter prospective study comprised adult patients with OAG having combined glaucoma and cataract surgery. Patients with qualifying treated preoperative intraocular pressure (IOP) of at least 21 mm Hg or higher and open angles were eligible. Evaluation was performed at baseline and 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. Intraoperative and postoperative high-resolution ultrasound imaging was used to assess Schlemm canal and anterior segment angle morphology, including distension of the trabecular meshwork due to the tensioning suture. RESULTS: Data from 54 eyes that had combined glaucoma and cataract surgery performed by 11 surgeons at 9 study sites were analyzed for this interim analysis. The mean baseline IOP was 24.4 mm Hg+/-6.1 (SD) with a mean of 1.5+/-1.0 medications per eye. In all eyes, the mean postoperative IOP was 13.6+/-3.8 mm Hg at 1 month, 14.2+/-3.6 mm Hg at 3 months, 13.0+/-2.9 mm Hg at 6 months, and 13.7+/-4.4 mm Hg at 12 months. Medication use dropped to a mean of 0.2+/-0.4 per patient at 12 months. Surgical complications were reported in 5 eyes (9.3%) and included hyphema (n=3, 5.6%), Descemet tear (n=1, 1.9%), and iris prolapse (n=1, 1.9%). Transient IOP elevation of more than 30 mm Hg was observed in 4 eyes (7.3%) 1 day postoperatively. CONCLUSION: Circumferential viscodilation and tensioning of Schlemm canal combined with clear corneal phacoemulsification and posterior chamber IOL implantation was a safe and effective procedure to reduce IOP in adult patients with OAG.     

小切口白内障囊外摘出联合人工晶状体植入术后眼前节变化分析

目的探讨小切口白内障囊外摘出联合人工晶状体植入术后患者眼前节的变化。方法对104例(104眼)老年性白内障患者施行小切口囊外摘出联合人工晶状体植入术,对手术前后患者的眼压、前房深度、角膜屈光力(K值)、前房角进行对比观察。结果术后1个月时眼压为(12.96±1.87)mmHg(1kPa=7.5mmHg),较术前(13.61±1.56)mmHg有所下降,但差异无统计学意义(t=0.396,P>0.05)。术前前房深度为(2.98±0.39)mm,术后为(4.16±0.56)mm,差异有显著统计学意义(t=5.431,P<0.01)。术后K值较术前有所增加,但差异无统计学意义(t=0.461,P>0.05)。术后前房角镜检查均可见小梁功能区,术前、术后前房角情况分类比较,差异有显著统计学意义(χ2=42.16,P<0.01)。结论小切口白内障手术有效地改善了患者前房角宽度及前房深度。     

Evaluation of Verisyse and Artiflex phakic intraocular lenses during accommodation using Visante optical coherence tomography

PURPOSE: To perform a dynamic study of the relationship between Verisyse (AMO) and Artiflex (Ophtec B.V.) phakic intraocular lenses (pIOLs) and anterior chamber structures during accommodation using optical coherence tomography (OCT) (Visante, Carl Zeiss Meditec, Inc.) SETTING: Institutional practice. METHODS: Eleven myopic patients were randomly selected to have implantation of a Verisyse pIOL in 1 eye and an Artiflex pIOL in the other. Using a 2-dimensional image, dynamic measurements of the relationship between the anterior surface of the pIOL and the corneal endothelium, the posterior surface of the pIOL and the anterior surface of the crystalline lens, and the pupil diameter were performed using Visante OCT. Physiological accommodation was stimulated by adding lenses in 1.00 diopter (D) steps from +1.00 to -7.00 D. RESULTS: Both groups had a significant decrease in pupil diameter (P<.0001, generalized linear model [GLM]) and in the distance between the anterior surface of the pIOL and the corneal endothelium (P<.0001, GLM) with accommodation. There were no statistically significant changes in the distance between the posterior surface of either pIOL and the anterior surface of the crystalline lens (P = .2845, GLM). There were no statistically significant differences between the 2 pIOLs in any measurement (P>.05, GLM). CONCLUSIONS: The results fit with Helmholtz' theory of accommodation as forward movement of the diaphragm iris-crystalline lens was seen. There was a decrease in the distance between the pIOL and corneal endothelium and in the pupil diameter, whereas the distance between both pIOLs and the crystalline lens remained constant throughout the accommodation examination. This suggests that the risk for cataract from intermittent contact between the crystalline lens and IOL from accommodative effort is unlikely.     

原发性闭角型青光眼行超声乳化联合房角分离术后房角改变

目的:观察白内障超声乳化吸除并人工晶状体植入联合房角分离术治疗合并有白内障的原发性闭角型青光眼术前术后房角的改变。方法:回顾性分析合并有白内障的闭角型青光眼患者35例(37眼),其中前房角关闭范围≤180°者16眼,>180°者21眼,均在表面麻醉下行角巩膜隧道切口行白内障超声乳化吸除折叠式人工晶状体植入联合房角分离术,对其手术前后的房角状态,眼压,中央前房深度,视力进行对照观察。结果:随访3～24mo术后房角状态与术前比有3眼大部分开放,余房角均开放,随访期内未见房角关闭及粘连范围扩大,末次随访平均眼压(14.3±4.1)mmHg,较术前用药后平均眼压(26.4±3.2)mmHg明显降低,差异具有统计学意义(t=5.86,P<0.01),中央前房深度由术前的(2.0±0.3)mm,增加到术后的(3.2±0.4)mm,视力除2眼有视神经萎缩外,余均有不同程度提高。结论:对于合并有白内障的闭角型青光眼的治疗,行白内障超声乳化吸除折叠式人工晶状体植入联合房角分离术治疗能有效地降低眼压,开放房角,加深前房,提高视力,与滤过性手术相比,手术并发症少,是有效且安全的手术方法。     

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.     

Position of rigid and foldable iris-fixated myopic phakic intraocular lenses evaluated by Scheimpflug photography

PURPOSE: To evaluate the postoperative intraocular positional stability of 1 rigid poly(methyl methacrylate) (PMMA) phakic intraocular lens (pIOL) model and 2 foldable polysilicone-PMMA iris-fixated pIOL models. SETTING: Department of Ophthalmology, Johann Wolfgang Goethe-University Frankfurt am Main, Germany. METHODS: One of 3 iris-fixated pIOL models (Artisan, Artiflex I, and Artiflex II, Ophtec BV) was implanted in 45 eyes of 26 patients with myopia or myopic astigmatism. The central distance between the pIOL and corneal endothelium and between the pIOL and anterior surface of the crystalline lens was evaluated using Scheimpflug photography 6 and 12 months after surgery. RESULTS: The mean preoperative spherical equivalent was -9.32 diopters +/- 1.78 (SD) (range -6.5 to -13.5 D). Each IOL model was implanted in 15 eyes. The median distance from the central corneal endothelium to the anterior surface of the pIOL at 6 months and 12 months was 2.65 mm and 2.64 mm, respectively, in the Artisan group, 2.47 mm and 2.50 mm, respectively, in the Artiflex I group, and 2.48 mm and 2.52 mm, respectively, in the Artiflex II group. The median distance between the posterior surface of the pIOL and the anterior surface of the crystalline lens at 6 months and 12 months was 0.40 mm and 0.48 mm, respectively, in the Artisan group, 0.53 mm and 0.55 mm, respectively, in the Artiflex I group, and 0.68 mm and 0.66 mm, respectively, in the Artiflex II group. At 12 months, the distance between the pIOL and crystalline lens was statistically significantly greater in the Artiflex II group than in the Artisan group (P<.01). CONCLUSION: The intraocular position of rigid pIOLs and foldable silicone iris-supported pIOLs showed a difference between the 3 pIOL models in space to the crystalline lens and the corneal endothelium, which may affect long-term results in terms of IOL interaction with surrounding tissue.     

Long-term vision-threatening complications of phakic intraocular lens implantation for high myopia

AIM:To report the long-term vision-threatening complications in patients who underwent phakic intraocular lens (pIOLs) implantation for high myopia.METHODS:This study was designed from a consecutive series of phakic intraocular lens complication and corrective surgeries. Sixteen eyes of 13 patients had implantation of phakic intraocular lens for correction high myopia and developed serious complications have been included in this study. The mean age of patients was 38.6±6.35y (range 32-50y) and the mean time of history of pIOL implantation for high myopia was 6±2y (range 2-10y). Before corrective surgery, best spectacle-corrective visual acuity (BSCVA) ranged from perception to 20/200 in the eyes in which severe complications occurred.RESULTS:Corneal decompensation occurred in 12 eyes of 9 high myopic patients after anterior chamber pIOL implantation. Rhegmatogenous retinal detachment (RRD) occurred in 4 eyes of 4 high myopic patients following anterior chamber and posterior chamber pIOL implantation. Patients with corneal decompensation, had combined procedures consisting of pIOL removal and penetrating keratoplasty (PKP). Removals of pIOL, phacoemulsification and pars plana vitrectomy (PPV) with silicone oil tamponade were performed in patients with RRD. After corrective surgeries, all patients but one (P+, patient 2, right eye) achieved moderate BSCVA ranged from 20/200 to 20/50 at the last visit.CONCLUSION:Phakic IOLs may be effective for the correction of high myopia. Although these IOLs may have severe complications and it affects safety and efficacy of this surgery. As seen here, corneal decompensation and rhegmatogenous retinal detachment are possible postoperative vision-threatening complications of phakic IOLs. Patients must be carefully examined before and after surgery for possible endothelial cell loss and vitreoretinal problems.     

Posterior synechias following implantation of a foldable silicone iris-fixated phakic intraocular lens for the correction of myopia

A 45-year-old white woman with unilateral high myopia had uneventful implantation of a -9.0 diopter, foldable, iris-fixated Artiflex I anterior chamber phakic intraocular lens (pIOL) (Ophtec B.V.) in the right eye. Despite application of topical antibiotic and steroid agents for 4 weeks after surgery, iris pigment dispersion developed on the anterior surface of the crystalline lens. Two weeks later, the iris dispersion increased and posterior synechias developed from the iris to the crystalline lens next to the pIOL haptic at the 3 o'clock position. Consequently, pIOL re-enclavation was performed without surgically removing the posterior synechias. Initial and interim mydriatic and steroid eyedrops were administered 4 times a day. Regular follow-up examinations after re-enclavation (at 2, 3, 6, 12, and 24 months) confirmed a stable pIOL position by Scheimpflug photography. Two years after implantation, posterior synechias persisted at the 3 o'clock position, with iris dispersion on the crystalline lens and the posterior side of the pIOL, but with no signs of anterior chamber inflammation and no visual acuity loss.     

Cyclodialysis cleft secondary to removal of an anterior chamber phakic intraocular lens

We present a patient who had decreased visual acuity and hypotony in the left eye 2 months after removal of an anterior chamber phakic intraocular lens (pIOL). Gonioscopy demonstrated a cyclodialysis cleft at the 6 o'clock position in the region of the IOL footplate, which was confirmed by ultrasound biomicroscopy. A cyclodialysis cleft formation is one possible complication of pIOL removal. Careful gonioscopy evaluation before removal of pIOLs should be mandatory to assess the amount of fibrosis and the presence of synechia between the IOL and the surrounding tissues.     

Anterior segment optical coherence tomography for evaluation of changes in anterior chamber angle and depth after intraocular lens implantation in eyes with glaucoma

PURPOSE: To examine anterior chamber depth (ACD) and anterior chamber angle (ACA) in patients with glaucoma after cataract extraction with an anterior optical coherence tomography (OCT) system. METHODS: A new commercially available 1310 nm infrared light anterior segment OCT system was used for anterior chamber evaluation. Sixty patients (n=20 with primary open angle glaucoma [POAG], n=20 with angle closure glaucoma [ACG], and n=20 with no known glaucoma as control group) with a mean age of 68.8+/-13.9 years undergoing cataract surgery were enrolled. RESULTS: Before cataract surgery, ACD and ACA of the ACG group were significantly lower compared to the POAG and control groups (ACD p<0.005; ACA p<0.005). After cataract extraction, ACD and ACA increased significantly in the ACG group (3.1+/-0.4 mm vs 1.8+/-0.2 mm, p<0.005 and 32.3 degrees +/-7.7 degrees vs 16.0 degrees +/-4.7 degrees , p<0.005). In the POAG and control groups, ACD and ACA also increased postoperatively, but not as much as in the ACG group. After cataract extraction, IOP decreased significantly in the glaucoma groups (ACG: 15.6+/-6.1 vs 18.6+/-5.7 mm Hg, p=0.008; POAG: 16.2+/-3.4 vs 20.7+/-8.0 mmHg, p=0.02) and was almost the same in all three groups after surgery (control group after surgery: 15.2+/-2.8 mmHg). CONCLUSIONS: Both ACD and ACA increased significantly after cataract extraction and IOL implantation. IOP reduction after surgery was higher in the glaucoma groups compared to the control group.     

Phakic intraocular lenses part 1: historical overview, current models, selection criteria, and surgical techniques

In this 2-part overview, the current status of phakic intraocular lens (pIOL) surgery to correct refractive errors is reviewed. Three types of pIOLs, categorized by their intraocular position, are included: angle-supported anterior chamber, iris-fixated anterior chamber, and posterior chamber (usually fixated in the ciliary sulcus). Part 1 reviews the main models of each pIOL type, the selection criteria, and the surgical techniques, with emphasis on currently available pIOLs. Bioptics, adjustable refractive surgery, and enhancements are addressed, and applications of the new anterior segment imaging techniques are reviewed.