Posterior Surface Of Intraocular Lens Research Articles

Effect of anatomical differences and intraocular lens design on negative dysphotopsia.

To assess the effect of ocular anatomy and intraocular lens (IOL) design on negative dysphotopsia (ND). Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands. Ray-tracing study based on clinical data. Ray-tracing simulations were performed to assess the effect of anatomical differences and differences in IOL design on the peripheral retinal illumination. To that end, eye models that incorporate clinically measured anatomical differences between eyes of patients with ND and eyes of pseudophakic controls were created. The anatomical differences included pupil size, pupil centration, and iris tilt. The simulations were performed with different IOL designs, including a simple biconvex IOL design and a more complex clinical IOL design with a convex-concave anterior surface. Both IOL designs were analyzed using a clear edge and a frosted edge. As ND is generally considered to be caused by a discontinuity in peripheral retinal illumination, this illumination profile was determined for each eye model and the severity of the discontinuity was compared between eye models. The peripheral retinal illumination consistently showed a more severe discontinuity in illumination with ND-specific anatomy. This difference was the least pronounced, 8%, with the frosted edge clinical IOL and the most pronounced, 18%, with the clear edge biconvex IOL. These results show that small differences in the ocular anatomy or IOL design affect the peripheral retinal illumination. Therewith, they can increase the severity of ND by up to 18%.

Phacofragmentation as an Effective Tool for Removal of Silicone Oil Adherent to Posterior Chamber Intraocular Lenses.

To assess usefulness of phacofragmentation probe in the removal of silicone oil (SO) adherent to intraocular lenses (IOLs) during a SO removal procedure. A 20-gauge (G) phacofragmentation probe was used to emulsify and remove SO adherent to IOLs during 23-G vitrectomy for SO removal. The superotemporal 23-G cannula was removed, and 20-G sclerotomy was made by using a 20-G MVR blade. In all cases used, SO adherent to the posterior surface of posterior capsule IOLs and anterior chamber IOLs was easily removed using a phacofragmentation probe. No intraoperative complications or IOL damage were noted. We describe a simple, quick and reliable method of SO removal from all types of IOLs by using a phacofragmentation probe during SO removal surgery. This simple method can prevent IOL removal and replacement due to adherent SO bubbles in pseudophakic eyes that were previously filled with SO.

Effect of capsular tension ring implantation on capsular stability after phacoemulsification in patients with weak zonules: a randomized controlled trial. CTR implantation in cataract patients with weak zonules

BackgroundThe use of capsular tension ring (CTR) implantation to treat cataract patients with weak zonules is still controversial. The aim of this study was to examine the effects of CTR implantation on capsular stability after phacoemulsification in patients with weak zonules, especially patients who have undergone pars plana vitrectomy (PPV) or those who suffer from severe myopia.MethodsA total of 42 patients who underwent phacoemulsification and received an intraocular lens (IOL) were randomized to undergo CTR implantation or not. The control and CTR groups were compared in terms of uncorrected distant visual acuity (UDVA), best corrected distant visual acuity (BCDVA), refractive prediction error, the area of anterior capsulorhexis, and IOL inclination angle. Follow-up visits were conducted postoperatively at 1 day, 1 week, 1 month and 3 months. Subgroup analyses were performed based on PPV and severe myopia.ResultsSurgery significantly improved UDVA and BCDVA to similar extents in CTR and control patients, and refraction prediction error was similar between the two groups at all follow-up times. At 3 months after surgery, the area of anterior capsulorhexis was significantly larger in CTR patients than in controls (p = 0.0199). These differences were also significant between the subgroups of patients with severe myopia. Vertical IOL inclination was less within CTR groups at 3 months after surgery, especially in patients with severe myopia (p = 0.0286). At 1 week postoperatively, the proportion of individuals whose posterior lens capsule that had completely adhered to the posterior IOL surface was significantly higher among CTR patients (p = 0.023). No serious surgical complications were observed.ConclusionCTR implantation can benefit cataract patients with weak zonules by maintaining the shape of the capsular bag, reducing capsule shrinkage and stabilizing IOL inclination.Trial registrationChinese Clinical Trial Registry ChiCTR-INR-17011217, date of registration April 22, 2017, prospectively registered.

Measurement of Force Required for Anterior Displacement of Intraocular Lenses and Its Defining Parameters.

Intraocular stability during or after cataract and glaucoma filtration surgeries and vitreous surgery with a gas/silicone oil tamponade might differ among intraocular lenses (IOLs). We used six different one-piece IOL models and measured the force that displaced the IOLs from the vitreous cavity to anterior chamber as a measure of stability against the pressure gradient between the anterior and posterior IOL surfaces. We measured IOL hardness, haptics junction area, and posterior IOL bulge to identify what determines the IOL displacement force. The KOWA YP2.2 IOL (1.231 mN) required significantly greater force than the HOYA XY1 (0.416 mN, p = 0.0004), HOYA 255 (0.409 mN, p = 0.0003), Alcon SN60WF (0.507 mN, p = 0.0010), and Nidek NS60YG (0.778 mN, p = 0.0186) IOLs; J&J ZCB00V IOL (1.029 mN) required greater force than the HOYA XY1 (p = 0.0032) and HOYA 255 (p = 0.0029) IOLs; the Nidek NS60YG IOL required greater force than the HOYA 255 (p = 0.0468) IOL. The haptics junction area was correlated positively with the IOL displacement force (r = 0.8536, p = 0.0306); the correlations of the other parameters were non-significant. After adjusting for any confounding effects, the haptics junction area was correlated significantly with the IOL displacement force (p = 0.0394); the IOL hardness (p = 0.0573) and posterior IOL bulge (p = 0.0938) were not. The forces that displace IOLs anteriorly differed among one-piece soft-acrylic IOLs, and the optics/haptics junction area was the major force determinant.

Comparative effects of various types of toric intraocular lenses on astigmatism correction

BackgroundCurrently, various types of toric intraocular lenses (IOL) have been manufactured and can be divided into three types according to the location of correction component; front-toric IOL (correction on anterior IOL surface), back-toric IOL (correction on posterior IOL surface), and bi-toric IOL (correction on both anterior and posterior IOL surfaces). In this study, we aimed to investigate the effectiveness of reducing corneal astigmatism of either normal or post-penetrating keratoplasty (PKP) corneas according to the type of implanted toric IOLs.MethodsMedical records were retrospectively reviewed in 370 patients who had undergone phacoemulsification with posterior chamber toric IOL insertion (front-toric IOL, back-toric IOL or bi-toric IOL). Subjects were divided into 2 groups; subjects who had no history of corneal disease with corneal astigmatism more than 1.00 diopters (D) (G1) and subjects who received previous PKP with all corneal sutures removed and had corneal astigmatism more than 1.25 D (G2). Preoperatively intended target from SRK/T was evaluated. Refractive astigmatism and its vector analysis (J0, J45), mean numerical error (MNE) and mean absolute error (MAE) were assessed at least a month after cataract surgery.ResultsMean preoperative corneal astigmatisms were 2.2 D and 4.0 D in G1 and G2, respectively. There was significant reduction of mean postoperative refractive astigmatism to 0.89 D in G1 and to 2.33 D in G2. In G1, bi-toric IOL showed significantly more improved refractive astigmatism than back-toric IOL. In G2, no difference in refractive astigmatism according to toric IOL type was observed. While G2 showed no difference in MNE among toric IOLs, in G1, bi-toric IOL showed significant hyperopic shift compared to back-toric IOL. In both groups, there was no significant difference in MAE according to type of IOL. No postoperative complications were observed.ConclusionOur study suggests that all types of toric IOL are beneficial in correcting astigmatism of normal and post-PKP corneas. Noticeably, bi-toric IOL showed significantly better results in refractive astigmatism than back-toric IOL in normal cornea. However, bi-toric IOL showed a more hyperopic shift compared to back-toric IOL. Among post-PKP corneas, all types of toric IOL showed similar results.

Condensation on intraocular lenses during vitrectomy: effect of perfluorocarbon liquids

Purpose: To evaluate whether perfluorocarbon (PFO) liquids can exacerbate condensation on intraocular lenses (IOL).Methods: Two separate experiments were carried out. In the first experiment, a two-segment chamber was constructed out of glass and acrylic panels to serve as an in-vitro eye model. The chamber was placed on a non-activated cooling plate with two IOLs of the same material, one in each segment. 2.0 ml of PFO and/or water for the control were placed in the respective receptacle. The cooling plate was then activated to the desired temperatures. Condensation on the lenses was visually assessed via high-definition ultra-zoom camera by trained observers for three temperatures and three IOL materials.In the second experiment, Fourier transform infrared (FTIR) spectroscopy wasemployed to determine the composition of the droplets forming after condensation.Results: The presence of PFO liquid in a closed chamber exacerbates the intensity and likelihood of condensation on all intraocular material types. Condensation of PFO on surfaces in the presence of water was confirmed with FTIR spectroscopy by the isolation of specific absorption bands. Furthermore, material type also affects the characteristics of condensation, with silicone lenses inducing the fastest rate and intensity of condensation.Conclusions: Our study shows that the presence of perfluoro-n-octane is a significant factor in the formation of condensation on the posterior surface of IOLs when performing vitrectomy in a pseudophakic patient with posterior capsulotomy.

Prediction of the true IOL position

PurposeTo develop algorithms for preoperative estimation of the true postoperative intraocular lens (IOL) position to be used for IOL power calculation.SettingMoorfields Eye Hospital NHS Foundation Trust, London, UK.MethodsFifty patients were...

Three-dimensional ray-tracing model for the study of advanced refractive errors in keratoconus.

We propose a numerical three-dimensional (3D) ray-tracing model for the analysis of advanced corneal refractive errors. The 3D modeling was based on measured corneal elevation data by means of Scheimpflug photography. A mathematical description of the measured corneal surfaces from a keratoconus (KC) patient was used for the 3D ray tracing, based on Snell's law of refraction. A model of a commercial intraocular lens (IOL) was included in the analysis. By modifying the posterior IOL surface, it was shown that the imaging quality could be significantly improved. The RMS values were reduced by approximately 50% close to the retina, both for on- and off-axis geometries. The 3D ray-tracing model can constitute a basis for simulation of customized IOLs that are able to correct the advanced, irregular refractive errors in KC.

Pars plana vitrectomy for posterior surface calcification in a silicone intraocular lens in asteroid hyalosis - a report of mistaken identity?

Dear editor Mehta et al recently reported removal of dystrophic calcification on the posterior surface of a silicone intraocular lens (IOL) in a patient with asteroid hyalosis.1 In this case the authors used pars plana vitrectomy (PPV) to successfully remove calcified deposits. We have recently tried unsuccessfully to use PPV to treat an 86 year old patient with calcification of a silicone IOL in the presence of asteroid hyalosis. We chose to avoid IOL exchange due to a history of Fuchs endothelial dystrophy and glaucoma in the left eye, and a failed corneal graft in a rubeotic eye on the right. Our patient did not have an intact posterior capsule having been treated with Nd:YAG capsulotomy 2 years previously, before the calcification occurred. A 25 gauge pars plana vitrectomy was performed after attempting to remove the deposits unsuccessfully from the posterior surface of the IOL with Nd:YAG laser. It was felt that PPV would be less likely to cause corneal decompensation than IOL exchange. In contrast to the experience of Mehta et al1 we found that the vitrector was unable to effectively remove many of the calcified deposits even with high vacuum. Instead the use of microforceps and a silicone tipped flute were required to ‘polish’ the IOL deposits (see Supplementary Video). Although we were able to remove a significant amount of the calcification in this way, the results were ultimately disappointing due to smearing of the deposits which were found to be ‘putty-like’ in consistency. Although there was some improvement in the clarity of the IOL on retroillumination, the patient reported very limited improvement in vision (6/18 preoperatively to 6/12 immediately after surgery), and on transillumination the posterior surface was significantly smudged (Figure 1). Figure 1 Smudging of posterior surface of IOL on transillumination postoperatively. Mehta et al reported that initially their patient underwent an unsuccessful Nd:YAG capsulotomy, however it was not made clear whether the posterior capsule remained intact.1 It has previously been suggested that direct contact of the IOL with the vitreous cavity caused by Nd:YAG capsulotomy accelerates the deposition of calcification on silicone IOLs,2 and other authors of larger case series of this condition have reported it to be mostly found after initial Nd:YAG capsulotomy,3,4 although reports of dystrophic calcification in the presence of an intact capsule do exist.5 Given our experience, we are unclear whether the photo presented demonstrates typical fibrous capsular opacity, or calcification of the posterior capsule rather than a true case of dystrophic calcification of the IOL optic. We believe this is an important distinction to make since we feel that vitrectomy is only likely to be successful if the posterior capsule is intact. A similar case of this condition has been published recently by Ullman and Gupta.5 They also used vitrectomy to treat dystrophic calcification, but found it to be ineffective at removing established calcification on the posterior IOL surface on more than one occasion. They suggested using prophylactic PPV to treat dystrophic calcification at an early stage before symptoms become established. We believe that vitrectomy and surgical capsulectomy should be considered as an alternative to Nd:YAG capsulotomy where IOL calcification is not yet established. It is likely that opening a significantly calcified posterior capsule by Nd:YAG capsulotomy in the presence of asteroid hyalosis will lead to significant future IOL dystrophic calcification. In established calcification of a silicone IOL we feel that vitrectomy is of limited value and IOL exchange should remain the standard treatment.

Bag and chamber flushing: a new method of using intracameral moxifloxacin to irrigate the anterior chamber and the area behind the intraocular lens

Intracameral moxifloxacin is currently administered by injecting small doses (0.05-0.2 mL) of either undiluted or diluted solutions. It is difficult to ensure delivery of small amounts of antibiotic into the area behind the intraocular lens (IOL). Moreover, the anterior chamber pressure decreases as the tip of irrigation is removed, often leading to contaminated fluid flowing into the chamber. Conventional intracameral injection administers the diluted antibiotic without irrigating the recontaminated anterior chamber. Therefore, we developed a method of intracameral moxifloxacin delivery which flushes both the anterior chamber and the area behind the IOL immediately after surgery. Surgical technique (bag and chamber flushing = BC flushing): After removing the viscosurgical device, 1.5-1.8 mL diluted moxifloxacin was injected. Both the anterior chamber and the area behind the IOL were irrigated by lifting the IOL edge so that a stream of solution could circulate behind the IOL. Experiment 1 (pig): The anterior chamber was filled with condensed milk, and irrigated with 150-fold diluted moxifloxacin (33.3 μg/mL) in six eyes (BC flushing) to observe the irrigating effect. The anterior aqueous humor was sampled. Experiment 2 (human): A conventional intracameral injection (500 μg/mL) or BC flushing (33.3 μg/mL) was followed by sampling 0.1 mL of the anterior aqueous humor in six eyes each. High-performance liquid chromatography was performed to determine antibiotic levels. Experiment 1: The antibiotic concentration in the anterior chamber was 33.0 μg/mL (99.0 % was displaced). The area behind the IOL was not effectively irrigated without inserting the cannula tip. Experiment 2: The final antibiotic concentration was 152.3 μg/mL using the conventional method and 29.4 μg/mL using the BC flushing (88.3 % was displaced). BC flushing technique enables surgeons to completely displace the anterior chamber including the posterior IOL surface, resulting in effective irrigation and a stable antibiotic concentration in virtually all cases.

Silicone intraocular lens surface calcification in a patient with asteroid hyalosis

To confirm a substance presence on the posterior intraocular lens (IOL) surface in a patient with asteroid hyalosis. An 80-year-old man had IOLs for approximately 12 years. Opacities and neodymium-doped yttrium aluminum garnet pits were observed on the posterior surface of the right IOL. Asteroid hyalosis and an epiretinal membrane were observed OD. An IOL exchange was performed on 24 March 2008, and the explanted IOL was analyzed using a light microscope and a transmission electron microscope with a scanning electron micrograph and an energy-dispersive X-ray spectrometer for elemental analysis. To confirm asteroid hyalosis, asteroid bodies were examined with the ionic liquid (EtMeIm+ BF4-) method using a field emission scanning electron microscope (FE-SEM) with digital beam control RGB mapping. X-ray spectrometry of the deposits revealed high calcium and phosphorus peaks. Spectrometry revealed that the posterior IOL surface opacity was due to a calcium-phosphorus compound. Examination of the asteroid bodies using FE-SEM with digital beam control RGB mapping confirmed calcium and phosphorus as the main components. Calcium hydrogen phosphate dihydrate deposits were probably responsible for the posterior IOL surface opacity. Furthermore, analysis of the asteroid bodies demonstrated that calcium and phosphorus were its main components.

Noncontact common-path Fourier domain optical coherence tomography method for in vitro intraocular lens power measurement

We propose a novel common-path Fourier domain optical coherence tomography (CP-FD-OCT) method for noncontact, accurate, and objective in vitro measurement of the dioptric power of intraocular lenses (IOLs) implants. The CP-FD-OCT method principle of operation is based on simple two-dimensional scanning common-path Fourier domain optical coherence tomography. By reconstructing the anterior and posterior IOL surfaces, the radii of the two surfaces, and thus the IOL dioptric power are determined. The CP-FD-OCT design provides high accuracy of IOL surface reconstruction. The axial position detection accuracy is calibrated at 1.22 μm in balanced saline solution used for simulation of in situ conditions. The lateral sampling rate is controlled by the step size of linear scanning systems. IOL samples with labeled dioptric power in the low-power (5D), mid-power (20D and 22D), and high-power (36D) ranges under in situ conditions are tested. We obtained a mean power of 4.95/20.11/22.09/36.25 D with high levels of repeatability estimated by a standard deviation of 0.10/0.18/0.2/0.58 D and a relative error of 2/0.9/0.9/1.6%, based on five measurements for each IOL respectively. The new CP-FD-OCT method provides an independent source of IOL power measurement data as well as information for evaluating other optical properties of IOLs such as refractive index, central thickness, and aberrations.

Quantification of glistenings in intraocular lenses using Scheimpflug photography

We describe a method of quantifying glistenings in intraocular lenses (IOLs) using Scheimpflug photography. Glistenings in hydrophilic acrylic IOLs implanted over a 10-year period were quantified subjectively at the slitlamp and by digital image analysis of Scheimpflug photographs; the latter involved analysis of glistenings in the anterior and posterior IOL surfaces. Glistenings were seen in all IOLs, with more in those with a longer postoperative period. This association was stronger with Scheimpflug quantification (r(S) = 0.70; P<.000) than with subjective quantification (r(S) = 0.32; P = .11). Anterior and posterior IOL glistenings developed similarly over time. Scheimpflug photography had a higher degree of objectivity than subjective staging of IOL glistenings and also provided information about the axial localization of the glistenings. This investigation indicated that IOL glistenings continued to increase for up to 10 years.

Postoperative low-grade endophthalmitis caused by biofilm-producing coccus bacteria attached to posterior surface of intraocular lens

We report a case of low-grade inflammation that developed in the anterior segment after cataract extraction with intraocular lens (IOL) implantation. The 57-year-old patient complained of blurred vision 2 weeks after phacoemulsification and IOL implantation in the right eye. Slitlamp biomicroscopy showed many nonpigmented keratoprecipitates. After antibiotic therapy failed, the IOL was removed and aqueous collected. Scanning electron microscopy of the IOL demonstrated many biofilm-producing cocci with slime on the IOL, and aqueous smears showed gram-positive cocci. Two weeks after removal of the IOL, the inflammation disappeared.

Evaluation of calcification of a hydrogel intraocular lens by optical coherence tomography

We describe 2 cases of calcification of hydrogel intraocular lenses (IOLs) evaluated by optical coherence tomography. Dense or slight surface opacities of hydrogel IOLs were detected initially by slitlamp biomicroscopy in a 55-year-old woman and a 77-year-old woman. The opacities resulted in complaints of hazy vision after uneventful phacoemulsification and IOL implantation. Optical coherence tomography was used to further assess the opacities and showed calcification by high reflectivity on the anterior and posterior IOL surfaces in the first patient and on the anterior surface in the second patient. No abnormal reflectivity was seen on the surface of a hydrophobic acrylic IOL in the second patient's fellow eye. Optical coherence tomography may be useful to detect calcification of a hydrogel IOL.

Posterior continuous curvilinear capsulorhexis with hydrogel and silicone intraocular lens implantation: Development of capsulorhexis size and capsule opacification

Purpose To evaluate the influence of primary posterior continuous curvilinear capsulorhexis (PCCC) on capsule opacification development and capsular bag changes within the first year after cataract surgery with 2 intraocular lenses (IOLs) of comparable design but different material. Setting Department of Ophthalmology, University of Vienna, Medical School, Vienna, Austria. Methods Thirty-seven patients with age-related cataract had bilateral small incision cataract surgery with a PCCC performed after capsular tension ring insertion. One eye was randomly assigned to receive a hydrogel IOL and the other eye, a silicone IOL. Standardized digital retroillumination photographs were taken 1 day, 1 week, and 1, 3, 6, and 12 months after surgery to evaluate changes in the dimensions of the anterior and posterior capsulorhexis opening area and the presence of anterior and posterior capsule opacification. Results The area of the anterior continuous curvilinear capsulorhexis (ACCC) opening was significantly reduced during the first 6 postoperative months. The shrinkage was more pronounced (–25%) in the silicone IOL group than in the hydrogel IOL group. Ten percent of eyes with a silicone IOL had marked shrinkage of the ACCC. The area of the PCCC did not change in eyes with a hydrogel IOL but was larger (+20%) in eyes with a silicone IOL. Anterior ongrowth was observed in 60% in the hydrogel group and in no eye in the silicone group. Anterior capsule fibrosis was observed in 90% in the silicone group and in 20% in the hydrogel group. Total closure of the PCCC was not observed within the first year, but posterior ongrowth was observed in 40% in the hydrogel group and 10% in the silicone group. Conclusions Anterior capsulorhexis shrinkage with concomitant posterior capsulorhexis enlargement was observed in eyes with a silicone IOL. The hydrogel IOL induced more ongrowth on the anterior and posterior IOL surfaces, whereas the silicone IOL induced more anterior capsule fibrosis. Total closure of the PCCC was not observed within the first year after surgery.

Management of Condensation on a Foldable Acrylic Intraocular Lens After Vitrectomy and Fluid-Air Exchange

To describe the management of condensation on the posterior surface of a foldable acrylic intraocular lens during vitrectomy and fluid-air exchange. A 70-year-old pseudophakic man with a foldable acrylic intraocular lens and open posterior capsule underwent vitrectomy and fluid-air exchange for repair of rhegmatogenous retinal detachment. During pars plana vitrectomy and fluid-air exchange, condensation immediately formed on the posterior surface of the foldable acrylic intraocular lens. This condensation, which prevented a view of the retina, was eliminated by wiping the posterior surface of the intraocular lens with a soft-tipped cannula. Although condensation may rapidly form on acrylic intraocular lenses during vitrectomy and fluid-air exchange, it can be managed readily by wiping with a soft-tipped cannula.

Moisture droplet formation on the posterior surface of intraocular lenses during fluid/air exchange

We investigated the conditions under which moisture droplets would form on intraocular lens (IOL) posterior surfaces during fluid/air exchange procedures in rabbits implanted with silicone or poly(methyl methacrylate) (PMMA) IOLs. Moisture droplets did not form when the posterior capsule was intact, regardless of IOL material or infusion fluid temperature. If a capsular tear was present, droplets formed with both IOL materials when balanced salt solution (BSS®) at ambient temperature was used as the infusion fluid. This effect was significantly more pronounced with silicone IOLs, resulting in an immediate loss of visualization of the fundus. In these cases, visualization was quickly restored by applying a viscoelastic to the posterior IOL surface.

Exfoliation Syndrome after Cataract Extraction

The authors describe three cases in which exfoliative material was noted on the posterior surface of intraocular lenses, years after extracapsular cataract extraction and lens implantation in eyes where no exfoliative material was seen before the operation. All three cases had an open posterior capsule before the exfoliative material was first seen. This phenomenon has not been previously presented in the literature.

The Formation of Moisture Droplets on the Posterior Surface of Intraocular Lenses During Fluid/Gas Exchange Procedures

To the Editor. —The formation of droplets of moisture on the posterior surface of silicone intraocular lenses (IOLs) during fluid/air exchange has been reported. The obvious concern regarding this phenomenon is the possibility that intraoperative viewing of the fundus could be impaired. The proposed mechanism for the phenomenon was moist air in the eye condensing on the IOL, which had been previously chilled by the infusion fluid used during vitrectomy. 1 We are investigating this phenomenon on silicone and polymethyl methacrylate IOLs (S1-18NB and PC-15B, respectively, Allergan Medical Optics, Irvine, Calif) implanted in rabbit eyes. Our operative procedure consists of a fluid/air exchange after vitrectomy, with observation of droplet formation using a quantitative grading system. Preliminary results demonstrate that droplets form on both lenses only when the posterior capsule is opened. Droplet formation is more pronounced with silicone lenses but has been cleared in all cases with the application of