Two cases of Z syndrome with the Crystalens after uneventful cataract surgery

CRYSTALENS REPOSITIONING WITH SCLERAL SUTURE TECHNIQUE

PURPOSE

To present a surgical technique that allows rescue (repositioning) of a dislocated Crystalens model intraocular lens using scleral sutures.

METHODS

The surgical technique is described with supplemental video.

RESULTS

The technique was used in one patient with 3 months of follow-up information. The intraocular lens was well-positioned, and the visual acuity is 20/20, without adverse events.

CONCLUSION

Scleral suture techniques for repositioning of the Crystalens offer a suitable alternative to intraocular lens exchange.

Intraoperative wavefront aberrometry to determine planar endpoint for the repositioning of vaulted accommodative IOLs

Accommodative intraocular lenses (IOLs) are suitable options for patients desiring less dependence on spectacles after cataract surgery. Accommodative IOLs do not require diffractive optics and, therefore, might be used in a wider range of patients who have mild comorbidities or wish to avoid photopsia associated with diffractive IOLs. However, a small percentage of patients have experienced vault, or capsular contraction syndrome (CCS), due to fibroblastic metaplasia of lens epithelial cells. Early detection of CCS might be managed with Nd:YAG capsulotomy; however, accommodative IOLs with significant CCS have required viscodissection of the fibrosis and placement of a capsular tension ring. A challenge with this maneuver is using the operating microscope to determine whether the accommodative IOL has returned to planar position. This article describes a new technique using serial intraoperative wavefront aberrometry measurements of lenticular astigmatism during accommodative IOL repositioning to determine a planar endpoint in the reduction of vault.

Intraocular Lens Complications: Decentration, Uveitis-Glaucoma-Hyphema Syndrome, Opacification, and Refractive Surprises

As cataract surgery has evolved, intraocular lens (IOL) complications are rare. The purpose of this review was to report the incidence, diagnosis, and management of IOL decentrations, uveitis-glaucoma-hyphema (UGH) syndrome, IOL opacifications, and refractive surprises. Literature review was performed by searching PubMed, MEDLINE, EMBASE, and the Cochrane Controlled Trial Database and the reference lists of original studies as well as reviews. Intraocular lens decentrations and dislocations can appear at any time, particularly in patients with predisposing factors such as pseudoexfoliation, prior vitreoretinal surgery, or trauma. Recognizing when they require surgical intervention for UGH or to improve visual function is critical in limiting long-term sequela. Intraocular lens opacifications such as glistenings rarely require intervention, but others, such as subsurface nanoglistenings, calcifications, or discolorations, may require IOL exchange. Finally, despite our best efforts to enhance measurements and IOL calculations, refractive surprises still occur. Intraocular lens complications are uncommon with modern cataract surgery. A number of these complications require proper identification and care to optimize patient outcomes.

Lens exchange for management of accommodative intraocular lens tilting

Accommodative intraocular lens (IOL) tilting, the so-called Z syndrome, is a rare complication of Crystalens (Bausch and Lomb) implantation. We report a significant IOL tilting and subsequent high lenticular astigmatism due to posterior capsular fibrosis 2 months after uncomplicated cataract surgery and Crystalens (AT50AO) implantation. The attempt to correct IOL position with neodymium-yttrium-aluminum garnet laser was unsuccessful, and Crystalens exchange with in-the-sulcus, three-piece monofocal IOL was performed. Accommodative IOL tilting could occur early after the surgery. Laser capsulotomy may be the first intervention to restore IOL position, but patients with a higher amount of lenticular astigmatism may require surgical intervention and IOL exchange.

Advances and challenges of intraocular lens design [Invited]

Phacoemulsification technique with intraocular lens implantation has been a common treatment for cataract patients. With rising demand among the public, new technologies for lens design have emerged to minimize intraocular aberrations, improving visual quality to the largest extent. This paper systematically reviews the development of materials applied in lens manufacturing, the different categories of intraocular lenses, and respective design principles. The advantages and potential drawbacks of intraocular lenses are illustrated in the paper, and prospective research to improve the design are presented in the end.

Correction of presbyopia: An integrated update for the practical surgeon

Presbyopia results from loss or insufficiency of the eye's accommodative ability, and clinically manifests as the inability to focus near objects on the retina. It is one of the most common causes of visual impairment worldwide especially in adults of productive or working age. Various means of compensating for the loss of accommodative ability have been devised from optical tools such as spectacles and contact lenses, to topical medications and to surgical procedures. A comprehensive search on journal articles about topical and surgical correction of presbyopia was undertaken. The various techniques for presbyopia correction, as enumerated in these articles, are discussed in this paper with the addition of our personal experience and perspective on the future of these techniques.

[Capsule contraction syndrome in pseudophakia]

This is a review of the literature on capsule contraction syndrome (CCS) in pseudophakic patients that involves severe fibrosis along the margin of the anterior capsule's opening and progressive contraction of the capsular bag. Possible causes of CCS and principles of its prevention and treatment have been analyzed.

Positional accommodative intraocular lens power error induced by the estimation of the corneal power and the effective lens position

Purpose:

To evaluate the predictability of the refractive correction achieved with a positional accommodating intraocular lenses (IOL) and to develop a potential optimization of it by minimizing the error associated with the keratometric estimation of the corneal power and by developing a predictive formula for the effective lens position (ELP).

Materials and Methods:

Clinical data from 25 eyes of 14 patients (age range, 52–77 years) and undergoing cataract surgery with implantation of the accommodating IOL Crystalens HD (Bausch and Lomb) were retrospectively reviewed. In all cases, the calculation of an adjusted IOL power (P_IOLadj) based on Gaussian optics considering the residual refractive error was done using a variable keratometric index value (n_kadj) for corneal power estimation with and without using an estimation algorithm for ELP obtained by multiple regression analysis (ELP_adj). P_IOLadj was compared to the real IOL power implanted (P_IOLReal, calculated with the SRK-T formula) and also to the values estimated by the Haigis, HofferQ, and Holladay I formulas.

Results:

No statistically significant differences were found between P_IOLReal and P_IOLadj when ELP_adj was used (P = 0.10), with a range of agreement between calculations of 1.23 D. In contrast, P_IOLReal was significantly higher when compared to P_IOLadj without using ELP_adj and also compared to the values estimated by the other formulas.

Conclusions:

Predictable refractive outcomes can be obtained with the accommodating IOL Crystalens HD using a variable keratometric index for corneal power estimation and by estimating ELP with an algorithm dependent on anatomical factors and age.

A stepwise approach for the management of capsular contraction syndrome in hinge-based accommodative intraocular lenses

PURPOSE

The aims of this study are to define the various stages of capsular contraction syndrome (CCS) and its effect on refractive error with hinge-based accommodating intraocular lenses (IOLs) and to describe a systematic approach for the management of the different stages of CCS.

METHODS

Hinge-based accommodative IOLs function via flexible hinges that vault the optic forward during accommodation. However, it is the flexibility of the IOL that makes it prone to deformation in the event of CCS. The signs of CCS are identified and described as posterior capsular striae, fibrotic bands across the anterior or posterior capsule, and capsule opacification. Various degrees of CCS may affect hinge-based accommodating IOLs in a spectrum from subtle changes in IOL appearance to significant increases in refractive error and loss of uncorrected visual acuity. The signs of CCS and its effect on IOL position and the resulting changes in refractive error are matched to appropriate treatment plans.

RESULTS

A surgeon can avoid CCS and manage the condition if familiar with the early signs of CCS. If CCS is identified, yttrium-aluminum-garnet laser capsulotomy should be considered. If moderate CCS occurs, it may be effectively treated with insertion of a capsular tension ring. If CCS is allowed to progress to advanced stages, an IOL exchange may be necessary.

CONCLUSION

Surgeons should be familiar with the stages of CCS and subsequent interventions. The steps outlined in this article help to guide surgeons in the prevention and management of CCS with hinge-based accommodative IOLs in order to provide improved refractive outcomes for patients.

Combined phacoemulsification and trabectome for treatment of glaucoma

Ab interno trabeculectomy with the trabectome is a microincisional glaucoma surgery modality with an electrosurgical device to ablate the trabecular meshwork and inner wall of Schlemm canal to restore conventional outflow along its physiological route, thereby decreasing intraocular pressure. The device was approved by the FDA in 2004 and has since gained widespread use. Trabectome can be performed on its own or combined with cataract surgery for the treatment of ocular hypertension or advanced glaucoma with similar intraocular pressure reduction. It can be used after failed classical glaucoma surgeries and in narrow angles. Postoperative average intraocular pressure is independent of preoperative pressure and can be expected to be near 15 mm Hg with a theoretical minimum close to episcleral venous pressure. In combination with tube shunts, low intraocular pressures can be achieved during the hypertensive phase and long term. Although early postoperative hyphema is common, complications are rare and similar to those seen in cataract surgery, resulting in a safety profile that is favorable compared to older glaucoma surgeries. Aqueous angiography that is under development will allow anatomically targeted ablation.

Corrective Techniques and Future Directions for Treatment of Residual Refractive Error Following Cataract Surgery

Postoperative residual refractive error following cataract surgery is not an uncommon occurrence for a large proportion of modern-day patients. Residual refractive errors can be broadly classified into 3 main categories: myopic, hyperopic, and astigmatic. The degree to which a residual refractive error adversely affects a patient is dependent on the magnitude of the error, as well as the specific type of intraocular lens the patient possesses. There are a variety of strategies for resolving residual refractive errors that must be individualized for each specific patient scenario. In this review, the authors discuss contemporary methods for rectification of residual refractive error, along with their respective indications/contraindications, and efficacies.

Presbyopia-correcting intraocular lenses and corneal refractive procedures: a review for retinal surgeons

PURPOSE

To review the specific challenges and pitfalls that vitreoretinal surgeons may face when operating on eyes with presbyopia-correcting intraocular lenses or previous corneal refractive surgery. In addition, this review aims to familiarize vitreoretinal surgeons with specifications of currently available Food and Drug Administration-approved presbyopia-correcting intraocular lenses.

METHODS

Review of current literature performed with PubMed for search terms "presbyopia," "correction," "IOL," "vitreoretinal," "challenges," and "surgical" both singly and in combination as well as closely related terms.

RESULTS AND CONCLUSION

Specific intraoperative issues with presbyopia-correcting intraocular lenses that may be encountered include peripheral visualization, condensation, lens material issues particularly with silicone oil, decentration, Z-syndrome, and foveal image displacement. Every patient undergoing retinal surgery should also be asked about previous laser-assisted in situ keratomileusis/photorefractive keratectomy because those eyes require special attention to surface hydration and care to avoid epithelial removal if possible. Intracorneal ring segments and corneal inlays can cause effects similar to those of a small pupil. However, these can be managed with thorough preoperative evaluation and various intraoperative maneuvers. In addition, retinal physicians should be aware that macular disorders, such as age-related macular degeneration, may be exacerbated by potential loss of contrast sensitivity.

Clinical and quality of life data correlation with a single-optic accommodating intraocular lens

Purpose

To examine a single-optic accommodating intraocular lens (IOL) visual performance by correlating IOL implanted eyes’ defocus curve with the intraocular aberrometric profile and the impact on the quality of life (QOL).

Methods

Prospective consecutive case series study including a total of 25 eyes of 14 patients with ages ranging between 52 and 79 years old. All cases underwent cataract surgery with implantation of the single-optic accommodating IOL Crystalens HD (Bausch & Lomb). Distance and near visual acuity outcomes, intraocular aberrations, the defocus curve and QOL (NEI VFQ-25) were evaluated 3 months after surgery.

Results

A significant improvement in distance visual acuity was found postoperatively (p = 0.02). Mean postoperative LogMAR uncorrected near visual acuity was 0.44 ± 0.23 (20/30). 60% of eyes had a postoperative addition between 0 and 1.5 diopters (D). The defocus curve showed an area of maximum visual acuity for the levels of defocus corresponding to distance and intermediate vision (−1 to +0.5 D). Postoperative intermediate visual acuity correlated significantly some QOL indices (r ≥ 0.51, p ≤ 0.03; difficulty in going down steps or seeing how people react to things that patient says) as well as with J₀ component of manifest cylinder. Postoperative distance-corrected near visual acuity correlated significantly with age (r = 0.65, p < 0.01).

Conclusions

This accommodating IOL seems to be able to restore the distance visual function as well as to provide an improvement in intermediate and near vision with a significant impact on patient's QOL, although limited by age and astigmatism. Future studies with larger sample sizes should confirm all these trends.

Intraocular electro-optic lens with ciliary muscle controlled accommodation

In this paper a concept is proposed of an intraocular lens implant with electro-optic accommodation of a variable-focus hybrid liquid-crystal-based lens. The dioptric strength of the lens is electronically controlled by a signal that is derived from the change of inductance of a sensing coil due to a marker implanted in the nearby contracting or decontracting ciliary muscle. Analytical, numerical and experimental results are reported on the dependency of the frequency of a Colpitts oscillator circuit on the location of a nearby conductive marker. A concept is also reported on the use as an electro-optic lens of a device based on a liquid crystal in planar alignment, which is held between a flat and a curved window coated with optically transparent and electrically conductive layers.

Visual and refractive outcomes after implantation of a fully diffractive trifocal lens

Background

The purpose of this study was to record the visual outcomes of patients treated by six surgeons after implantation of a trifocal lens.

Methods

The setting for this study comprised six ophthalmology units and eye clinics in Belgium and France, with a coordinating center in France, and data management and statistical analysis in France and Belgium. Ninety-four eyes from 47 patients were implanted with a trifocal FineVision^® intraocular lens by six surgeons. Monocular and binocular, uncorrected and best distance-corrected, and photopic and mesopic visual acuity was measured, as well as the defocus curve between +4 D and −4 D with best distance correction.

Results

Near and far monocular visual acuities were similar to the data published after bifocal intraocular lens implantation. Intermediate vision was improved, and was demonstrated by scores of near visual acuity as well as far visual acuity with defocus −1.5 D-add lens. Far vision is maintained in mesopic conditions.

Conclusion

The trifocal intraocular lens provides good far, intermediate, and near visual acuity.

Modern cataract surgery: unfinished business and unanswered questions

We summarize information, based on clinicopathologic studies over the past decade, on various cataract intraocular lens (IOL) procedures and modern "specialized" IOLs, that will help surgeons continuously improve long-term results for cataract patients. Although most operations do initially provide excellent refractive correction and visual rehabilitation, late complications occur. These sometimes are missed because they are outside of the routine period of follow-up care. We have tried to determine if the various techniques and IOLs truly deliver the long-term results that we desire. Most safety and efficacy information is derived from the manufacturer and is passed through the U.S. Food and Drug Administration (FDA). This is often based on limited, relatively short-term observations made by the manufacturer. After a lens receives FDA approval, there are few means to assess the outcome of each procedure and lens years later. We rarely hear of a 10- or 20-year follow-up study. We have found that one of the best means to assess long-term results is pathologic analyses. We discuss recently studied aspects of pathologic reactions, such as posterior capsule opacification, intracapsular fibrosis, glistenings, intralenticular opacification, and other issues with the various IOL platforms; we then present a clinicopathological overview of tissues and IOLs from our database. These include hydrophobic and hydrophilic acrylic designs, plate lenses, and a dual optic lens.