Plate-haptic Lens Research Articles

Comparison between clinical outcomes of two different designs of toric multifocal intraocular lenses

To compare the clinical outcomes of plate haptic and open-loop haptic toric multifocal intraocular lenses (IOLs). In this retrospective, comparative clinical trial, two different designs of multifocal toric IOL were implanted in 49 eyes of 38 cases with corneal astigmatism ≥ 0.75 Diopter (D). The cases that underwent AcrySof IQ restore multifocal toric IOL (Alcon, open-loop-haptic) implantation were assigned to Group1 (n=19) and the cases that underwent Acriva Reviol multifocal toric IOL (VSY, plate-haptic) implantation were assigned to Group 2 (n=30). After surgery, the groups were compared in terms of degree of IOL rotation, residual spherical refraction and astigmatism and uncorrected near and distance visual acuity. With regard to the results of postoperative 1st month, 3rd month, 6th month and 1st year, no difference was determined in terms of uncorrected distance visual acuity, spherical equivalent (SE), degree of astigmatism (CYL), degree of rotation, and uncorrected near visual acuity (p>0.05). Significant increase was determined in all postoperative follow-up periods in terms of the distance and near visual acuity as compared to preoperative values (p0.05). Clinical outcomes of plate haptic Acriva Reviol multifocal toric IOL and open-loop haptic Acrysof IQ multifocal toric IOL are similar. Both types of IOL effectively reduce astigmatism and provide satisfactory uncorrected distance and near visual acuities.

3D Scheimpflug measurement of posterior chamber plate haptic phakic intraocular lens/crystalline lens gap profile

Editor, I n the last decade, phakic intraocular lenses (PIOL) have risen to prominence as a means of correcting refractive error while leaving the crystalline lens untouched. (Kohnen et al. 2005) The Staar Collamer plate lens (Staar Surgical Company, Monrovia, CA, USA) is a widely used model as it is implanted through a smaller corneal incision. This letter reports a means of identifying the postoperative position of the plate haptic lenses and features such as lenticular decentration or bending along one meridian, which may account for postoperative complaints. Assessment is by means of Scheimpflug imaging, augmented by an in-house analysis method. Based on Pentacam (Oculus Optikgerate GmbH, Wetzlar, Germany) images, we measure the distance d (lm) between the PIOL and lens along a 5-mm-diameter circle, centred on the corneal apex. A perfectly centred PIOL should be equidistant from the natural lens along this circle making d a constant. The Pentacam can provide d at two points 2.5 mm to the left and right of the apical axis for all 25 Scheimpflug images in a single scan (Fig. 1A). Next, d is plotted as a function of the meridian h along which it was measured, after which a least squares fit is carried out with the function: dðhÞ 1⁄4 a1 cosðh þ /1Þ þa2 cosð2h þ /2Þ þ d0 ð1Þ

Biometry and Formula Accuracy With Intraocular Lenses Used for Cataract Surgery in Extreme Hyperopia

To audit intraocular lens (IOL) power predictions for cataract surgery in extreme hyperopia and to compare the accuracy across different biometry formulae and IOL types. A retrospective analysis of 76 eyes from 56 patients undergoing cataract surgery with IOLs ranging in power from 30 to 35 diopters (D). Axial lengths, corneal powers and anterior chamber depths were measured with ultrasound or optical methods, and the IOLMaster (Carl Zeiss Meditech, Inc, Dublin, California, USA) software was used to predict the refractive outcome for each IOL used. Differences between the predicted and actual postoperative refraction were then analyzed for each formula. In practice, 55% of patients were within +/-1.0 D of the refraction predicted by their surgeon. In theory, the Haigis formula would have given the smallest mean refractive error (+0.51 +/- 0.12 D), followed by the Hoffer Q (-0.70 +/- 0.14 D), Holladay 1 (-1.11 +/- 0.13 D), and SRK/T formulae (-1.45 +/- 0.14 D). The Haigis formula overpredicted the lens power required, which would have generated a myopic result. The other formulae underpredicted the lens power required and would have generated a hyperopic result. There was a significant difference between lens designs: the Haigis was more accurate for open-loop, whereas the Hoffer Q was more accurate for plate-haptic lenses. The anterior chamber depth measurement could also be used to predict changes in intraocular pressure after surgery. This represents the largest published series to date of biometry predictions for cataract surgery in extreme hyperopia and confirms the Haigis formula to be the most accurate. A consistent difference between open-loop and plate-haptic lenses suggests that haptic design may influence the effective lens position in very small eyes. We further propose a simple formula to optimize the Haigis and Hoffer Q formulae in patients with extreme hyperopia.

Anterior luxation of rollable intraocular lens

Dear Editor, Bimanual microincisional phacoemulsification surgery is a safe procedure with a very short learning period for an experienced cataract surgeon and rollable ultrathin intraocular lenses eliminate the need for enlargement of corneal incision.1 We report a rare case of late anterior subluxation of rollable plate haptic intraocular lens following an uncomplicated surgery. A 63-year-old female patient was operated for right eye cataract surgery by bimanual microphacoemulsification using stop and chop technique and an acrylic rollable plate-haptic intraocular lens (Micriol, Eyeol, UK) was implanted in the bag. The surgery was uneventful. The size of the capsulorhexis was small and so at the end of the procedure a relaxing incision was made on the superonasal part of the anterior capsule to prevent capsular phimosis. Postoperatively, the patient had best corrected visual acuity of 20/20 (on Snellen) at six weeks. Three months postoperatively; the patient came back with complaint of decreased vision in the operated eye. The patient had no history of trauma to the eye and the symptoms of blurred vision developed spontaneously over a period of few days. On examination, the visual acuity was reduced to 20/200. The slit-lamp examination revealed anterior subluxation of the nasal part of the lens with peaked pupil [Fig. 1]. This resulted in an unacceptably high astigmatic error. The patient was posted for dialing of the lens under topical anesthesia and the lens was dialed back in the bag with haptic lying away from the relaxing incision. Following the procedure the patient regained her best-corrected vision of 20/20 from day 1 and has continued to maintain her vision.Figure 1: Anterior subluxation of plate-haptic intraocular lens with peaked pupilThe posterior disclocation of the plate haptic intraocular lens has been known to occur after Yag capsulotomy.2 Anterior subluxation of the plate haptic lens is rare but has been reported in the past.3 A thin plate haptic rollable intraocular lens can get subluxated in the anterior chamber through the relaxing incision of the anterior capsulorhexis. Therefore an intact continuous curvilinear capsulorhexis and in the bag implantation is essential to prevent such a complication.

Long-Term Safety and Efficacy of Repositioning Dislocated Plate Haptic Intraocular Lenses in the Ciliary Sulcus

To report safety and efficacy outcomes of repositioning posterior dislocated plate haptic lenses (PHLs) in the ciliary sulcus (CS). Retrospective interventional case series. Fifteen consecutive eyes with dislocated PHL repositioned in the CS were reviewed retrospectively. Pars plana vitrectomy was required in 12 of 15 cases. The main outcome variables were initial and final best-corrected visual acuity (BCVA) and length of follow-up. All lenses remained centered for an average of 48.7 months (range 4 to 99 months) of follow-up with no recurrent dislocation, cystoid macular edema, chronic iritis, or iris chaffing. Initial and final BCVA of 20/40 or better was attained in 93.3% (14 of 15) and 66.7% (10 of 15) of eyes, respectively. Decline of final BCVA was attributable to secondary eye diseases and not related to repositioning. Our study reports dislocated PHL may be managed safely and effectively by placement in the CS with long-term stability under certain clinical scenarios.

Delayed posterior dislocation of silicone plate-haptic lenses after neodymium:yag capsulotomy

We report 4 cases of posterior dislocation of silicone plate-haptic intraocular lenses (iols) into the vitreous cavity occurring a mean of 16 months after neodymium:YAG laser posterior capsulotomy. In each case, no peripheral capsule defect was observed at the time of laser capsulotomy or at subsequent follow-ups. One case was treated with sulcus implantation of a 3-piece IOL, with the plate-haptic IOL left in the vitreous cavity. The other cases were managed with vitrectomy (2 pars plana, 1 anterior) to remove the plate-haptic lens with subsequent sulcus placement of a 3-piece IOL. Patients should be informed that posterior dislocation is an infrequent but possible complication of these lenses and may occur months and even years after implantation or laser capsulotomy.

Posterior capsule tear with plate-haptic silicone intraocular lens dislocation

We report a case of posterior capsule rupture and posterior dislocation of an intraocular lens (IOL) caused by the tip of a silicone plate-haptic lens. The dislocation occurred during IOL implantation after uneventful phacoemulsification in a patient with a small pupil. Discussed are the possible reasons for the complication and measures to prevent it.

Decentration of 3-piece versus plate-haptic silicone intraocular lenses

Purpose: To compare the incidence of decentration with 2 types of silicone intraocular lenses (IOLs).Setting: John A. Moran Eye Center, University of Utah Medical Center, Salt Lake City, Utah, USA.Methods: Selection criteria for this retrospective study included patients who had uncomplicated cataract surgery with a clear cornea or seieral tunnel incision with a curvilinear capsulorhexis and capsular bag implantation of a silicone IOL. After a mean follow-up of 14 months (range 12 to 18 months), 54 eyes implanted with a 3-piece lens (AMO SI-30) and 58 eyes implanted with a plate-haptic lens (Staar AA403) were examined for posterior chamber IOL decentration. The decentration criterion was 0.5 mm or more from the center of the pupil. Detailed chart review of preoperative and postoperative measurements was performed for each patient.Results: Eighteen of the 3-piece IOLs (33%) and 11 of the plate-haptic IOLs (20%) were decentered 0.5 mm or more (P = .129). Using photographic analysis, the mean IOL decentration with the 3-piece IOL (1.12 mm ± 0.198 [SD]) was significantly greater than with the plate-haptic IOL (0:632 ± 0.278 mm) (P < .001). No statistically significant correlation was found between the centered or decentered IOL groups' preoperative refraction, axial length, capsulorhexis size, type of incision, or rate of neodymium:YAG laser capsulotomy.Conclusions: No statistically significant difference was seen between the decentration rates of 3-piece and plate-haptic IOLs; however, the amount of decentration with the 3-piece IOL was significantly greater than with the plate-haptic IOL. Other factors did not contribute to IOL decentration.

Intraocular Pressure Changes after Phacoemulsification and Foldable Silicone Lens Implantation Using Healon GV®

The authors studied the intraocular pressure (IOP) changes after phacoemulsification with two different kinds of foldable silicone lens implantation using Healon GV® as viscoelastic substance. One hundred patients undergoing cataract surgery were enrolled in this study. Inclusion criteria were: absence of ocular hypertension or glaucoma. Patients were randomly assigned to plate haptic (Silens PH®, Domilens® Chiron Vision, Lyon, France) or three-piece (CeeOn™& ;920, Pharmacia spa, Milano, Italia) silicone intraocular lens (IOL) implantation. Following phacoemulsification and cortical aspiration, the capsular bag was reinflated with Healon GV. After foldable silicone IOL insertion residual Healon GV was removed from the anterior chamber. IOP was measured preoperatively and at 6, 24 h and 1 week postoperatively. Six hours postoperatively IOP was higher in the Silens PH group than in the CeeOn group (20.85±5.42 vs. 18.88±2.95 mm Hg, p = 0.026). The difference was confirmed after 24 h (21.02±5.18 vs. 17.34±3.18 mm Hg, p < 0.01). Despite the medical treatment (acetazolamide 250 mg orally every 6 h), at the 24-hour control 2 eyes with plate haptic silicone lens showed IOP values higher than 30 mm Hg. Slitlamp examination showed in both eyes a shallowing of the anterior chamber together with the evidence of capsular bag hyperdistension and capsular block resulting from the occlusion of the circular anterior capsule opening by the plate haptic IOL. Residual Healon GV removal from the anterior chamber was performed. At 1-week control both eyes showed normalization of IOP. The use of a plate haptic silicone lens may be associated with a more consistent retention of Healon GV in the eye with trapping in the capsular bag. Retained viscoelastic may cause either trabecular meshwork blockage by viscoelastic substance or postoperative capsular bag hyperdistension, anteroplacement of the IOL optic and capsular block from occlusion of the circular anterior opening by the IOL optic.

Transscleral Fixation of a Dislocated Silicone Plate Haptic Intraocular Lens via the Pars Plana

A method for transscleral fixation of silicone plate haptic posterior chamber intraocular lenses (PC IOLs) via the pars plana is described. One 10-0 polypropylene transscleral suture passed through the sclera and the PC IOL hole and a similar suture passed through the sclera only were withdrawn outside the eye thorough the pars plana and tied together. Pulling up the scleral end of one suture placed the PC IOL haptic in the sulcus and the knot was pulled outside the eye. Perfluorocarbon liquid was used during the procedure to safely manipulate the PC IOL. The PC IOL was well centered at 3 months of follow-up. Posteriorly dislocated silicone plate haptic PC IOLs can be safely sutured to the sclera via the pars plana by this method.

A Motorized Hand Piece for Injectable Lenses

Foldable lenses represent a major breakthrough in the effort to achieve ever smaller incisions. The plate-haptic or "taco-style" lenses are folded and implanted by a device called an injector. Although customized for each manufacturer's lens, the injectors all have a common design principle: the intraocular lens (IOL) is folded within a funnel-like structure of the tip and is advanced by a plunger that pushes and delivers the lens. To maintain optimal hand stabilization and injector management, both hands are usually required. This does not leave a hand to help with IOL positioning. To improve handling, a simple, mechanized system has been created for a new injector system that allows the delivery of the plate-haptic lens with one hand, in a pen-like fashion.

The Measurement of Vitreous Cavity Length and its Comparison Pre- and Postoperatively

Objectives: To determine an accurate method of measuring the vitreous cavity lengths in pseudophakic patients and to compare the pre- and postoperative vitreous cavity lengths in various lens styles and between eyes implanted with the same lens style. To determine which lens style helps maintain the vitreous cavity length closest to its preoperative state. Study Design: A prospective study involving patients implanted with silicone prolene loop, silicone plate haptic and polymethyl methacrylate one-piece intraocular lenses implanted in eyes having undergone cataract extraction with endocapsular phacoemulsification with capsulorhexis and with an intact capsular bag. Setting: Anaheim Eye Medical Group, private practice, Anaheim, California. Patients: Twenty-three patients selected randomly from the cataract patients in the practice. Results: In the eyes implanted with silicone prolene loop lenses, the optic had a spread of 3.15 mm in its location along the axis of the eye and in 80% of the patients, the vitreous cavity was lengthened by as much as 2.17 mm.In the silicone plate haptic group, the spread was 1.45 mm and in 50% the vitreous cavity was shortened, the greatest increase in vitreous cavity length being only 0.77 mm.Using the equipment available at Anaheim Eye Medical Group, the Storz™ LT biometric ruler, it was not possible to accurately determine the vitreous cavity length in eyes implanted with polymethyl methacrylate lenses. Conclusions: The plate haptic lens design is more effective in helping to maintain the preoperative vitreous cavity length. The great variation of the location of the prolene loop lens optic along the axis of the eye explains some of the postoperative refractive surprises with loop lenses. The size of the capsulorhexis has nothing to do with the location of the prolene loop lens optic along the axis of the eye. Because of the more consistent location of the plate haptic lens along the axis of the eye, the ‘A’ constant for a plate haptic lens is more meaningful than for a prolene loop lens.

Capsulotomy Rate in Silicon Plate Haptic and Prolene Loop IOLs

OBJECTIVE: To compare the incidence of YAG posterior capsulotomy between eyes' implanted with silicone prolene loop and plate haptic lenses, and to compare the incidence of posterior capsulotomy in the short-term (median implantation time of 10.5 months) and long-term (median implantation time of 30 months) in the patients implanted with the plate haptic lens. STUDY DESIGN: Retrospective study comparing the incidence of capsulotomy in patients from Anaheim Eye Medical Group having undergone outpatient cataract surgery by the same surgeon using endocapsular phacoemulsification and implantation with capsulorhexis with an intact anterior capsular rim and bag. PATIENTS: Two groups of plate haptic silicone lens implanted patients, one group of 141 and another of 301 patients, were compared to 253 patients implanted with the prolene loop silicone lens over the same implantation and follow-up times. In the second part of the study, 503 patients were studied. Of the 442 patients with a median follow-up time of 10.5 months, five had capsulotomies. The remaining 498 patients had a median implantation time of 30 months with a capsulotomy rate of 1.4%. RESULTS: The incidence of posterior capsulotomy in patients implanted with silicone plate haptic lenses was 1.1% with a median implantation time of 10.5 months compared to 7.1% in the prolene loop group with a median implantation time of 12 months (significance level of <0.0001). The incidence of capsulotomy in the plate haptic group with a median implantation time of 10.5 months was 1.1% and those with a median implantation time of 30 months was 1.4%, indicating a reduction in the rate of capsulotomy in the long term. CONCLUSIONS: The incidence of capsulotomy is lower in silicone plate haptic lenses when compared to silicone prolene loop lenses. The low incidence of capsulotomy in plate haptic lenses decreases with the passage of time.

Surgical complications and visual acuity results in 536 cases of plate haptic silicone lens implantation

Implantation of a plate haptic intraocular lens was planned in 536 cases. This paper reports the uncorrected and corrected visual acuities and complications in 33 patients in whom there were surgical complications that prevented implantation of the plate haptic lens. Excluding five patients (15%) who had pre-existing pathology, 21 (75%) had uncorrected acuity of 20/40 or better and 27 (96%) had corrected acuity of 20/40 or better five to six weeks postoperatively. The plate haptic lens can only be used with capsulorhexis and an intact anterior capsular rim and posterior capsule. Two alternative backup lens styles-a loop lens for placement in the torn bag or the sulcus and an anterior chamber lens-have to be in the operating room for each surgery.

Postoperative complications and uncorrected acuities after implantation of plate haptic silicone and three-piece silicone intraocular lenses

Complications after implantation of 503 plate haptic silicone intraocular lenses were compared with those after implantation of 253 silicone three-piece polypropylene loop lenses. The uncorrected visual acuities were also compared. Capsulorhexis and endocapsular phacoemulsification were used in all cases. The incidence of cystoid macular edema and posterior capsule opacification requiring a YAG capsulotomy were significantly higher in the cases with polypropylene three-piece loop lenses. Pigment dispersion and decentration also occurred more frequently in this group. This is probably because the 10.5 mm plate haptic lens is more rigid than the polypropylene loop lens. It also fixates more posteriorly within the capsular bag than the anteriorly located polypropylene lens. Patients implanted with a plate haptic silicone intraocular lens through a 3.5 mm scleral incision had significantly better uncorrected visual acuity at five to six weeks postoperatively than those with a three-piece silicone lens that required a 4.5 mm incision for insertion.