Matching the Patient to the Intraocular Lens: Preoperative Considerations to Optimize Surgical Outcomes.

The intraocular lens (IOL) selection process for patients requires a complex and objective assessment of patient-specific ocular characteristics, including the quality and quantity of corneal astigmatism, health of the ocular surface, and other ocular comorbidities. Potential issues that could be considered complications after surgery, including dry eye disease, anterior or epithelial basement membrane dystrophy, Salzmann nodular degeneration, and pterygium, should be addressed proactively. Aspheric IOLs are designed to eliminate the positive spherical aberration added by traditional IOLs to the pseudophakic visual axis. Spherical aberration may be a consideration with patient selection. Patient desire for increased spectacle independence after surgery is one of the main drivers for the development of multifocal IOLs and extended depth-of-focus (EDOF) IOLs. However, no one single multifocal or EDOF IOL suits all patients' needs. The wide variety of multifocal and EDOF IOLs, their optics, and their respective impact on patient quality of vision have to be understood fully to choose the appropriate IOL for each individual, and surgery has to be customized. Patients who have undergone previous LASIK or who have radial keratotomy and ocular pathologic features, including glaucoma, age-related macular degeneration, and epiretinal membrane, require specific considerations for IOL selection. Subjectively, patient-centered considerations, including visual goals, lifestyle, personality, profession, and hobbies, are key elements for the surgeon to assess and factor into an IOL recommendation. This holistic approach will help surgeons to achieve optimal surgical outcomes and to meet (and exceed) the high expectations of patients.

Comparison of visual outcomes and reading performance after bilateral implantation of multifocal intraocular lenses with bilateral monofocal intraocular lenses.

PURPOSE: To compare the visual acuity outcomes, contrast sensitivity function (CS) and reading ability in patients with bilateral multifocal intraocular lenses and patients with bilateral monofocal lenses. SETTING: Vizyon Eye Center, Denizli, Turkey. DESIGN: Comparative case series. METHODS: Consecutive bilateral cataract patients having implantation of Acriva Reviol MFM 611 multifocal IOLs (Group A) or Acriva BB UD 613 monofocal IOLs (Group B) were included. Parameters analyzed 6 months postoperatively included monocular uncorrected distance (UDVA), binocular uncorrected intermediate (UIVA), binocular uncorrected near (UNVA), CS and bilateral reading performance using MN Read. RESULTS: The study evaluated 42 eyes in Group A and 40 eyes in Group B. There were no statistically significant differences in UDVA between two groups postoperatively (p = .39). Binocular UIVA and binocular UNVA are better in Group A (p = .00, p = .00). Under photopic and scotopic conditions, contrast sensitivity results were decreased in Group A, especially at high spatial frequencies. No statistically difference were found in reading acuity, critical print size and maximum reading speed between two groups (p = .57, p = .62, p = .22). CONCLUSIONS: This study concludes that multifocal lenses are reliable and efficient replacements for reading glasses since they significantly improve the vision for near or intermediate distance activities.

[Toric add-on intraocular lenses for correction of high astigmatism after pseudophakic keratoplasty]. / Torische AddOn-Intraokularlinsen zur Korrektur hoher Astigmatismen nach pseudophaker Keratoplastik.

Perforating keratoplasty shows good morphological results with a clear cornea; however, a limiting factor is often the resulting astigmatism, which cannot be corrected with either glasses or contact lenses (CL) in up to 20% of the patients. We retrospectively investigated 15 patients after pseudophakic perforating keratoplasty, who received implantation of toric add-on intraocular lenses (IOL) to correct astigmatism. The mean preoperative astigmatism of 6.5 diopter (dpt) could be reduced to a mean postoperative value of 1.0 dpt. The mean visual acuity could be improved from a preoperative value of sc <0.05 (cc 0.6) to a postoperative value of sc 0.4 (cc 0.63). There were no complications except for one case of a lens extension tear. Based on our good experiences we now provide toric add-on IOL to all patients with pseudophakic perforating keratoplasty when this cannot be corrected or only insufficiently corrected by conservative methods.

Intraocular lens based on double-liquid variable-focus lens.

In this work, the crystalline lens in the Gullstrand-Le Grand human eye model is replaced by a double-liquid variable-focus lens, the structure data of which are based on theoretical analysis and experimental results. When the pseudoaphakic eye is built in Zemax, aspherical surfaces are introduced to the double-liquid variable-focus lens to reduce the axial spherical aberration existent in the system. After optimization, the zoom range of the pseudoaphakic eye greatly exceeds that of normal human eyes, and the spot size on an image plane basically reaches the normal human eye's limit of resolution.

Optimal amount of anisometropia for pseudophakic monovision.

PURPOSE: To determine the optimal target anisometropia for pseudophakic monovision. METHODS: Thirty-five bilaterally pseudophakic patients who received monofocal intraocular lenses were included in the study. Binocular corrected distance visual acuity (CDVA) and binocular distance-corrected near visual acuity (DCNVA) and stereoacuity were measured after simulating 1.00, 1.50, and 2.00 diopters (D) of monovision by adding the appropriate spherical lens to the nondominant eye. We presumed that mean binocular DCNVA of 20/40, binocular CDVA of 20/25, and stereoacuity <100 seconds of arc (arc sec) were necessary for successful monovision. RESULTS: With no anisometropia, mean binocular DCNVA was 20/97, binocular CDVA was 20/20, and mean stereoacuity was 71 arc sec. With 1.00 D of monovision, mean binocular DCNVA was only 20/60, although binocular CDVA and mean stereoacuity were sufficient. With 1.50 D of monovision, binocular DCNVA was 20/38, binocular CDVA at other distances exceeded 20/21, and stereoacuity was 100 arc sec, which was a 29-arc sec reduction. With 2.00 D of monovision, binocular DCNVA reached 20/31, but stereoacuity was 158 arc sec, which was an 87-arc sec reduction. The number of patients who met the criteria for successful monovision was significantly greater with 1.50 D of monovision than with 1.00 or 2.00 D of monovision (P=.0134). CONCLUSIONS: Pseudophakic monovision with anisometropia of 1.50 or 2.00 D provides useful binocular visual acuity from far to near. However, because stereopsis with 2.00 D of monovision is substantially impaired, approximately 1.50 D of anisometropia is thought to be optimal for successful monovision.

Comparison of various spherical aberration compensation methods in pseudophakic eyes.

PURPOSE: To provide a numerical comparison of the efficiency of spherical aberration (SA) compensation methods commonly used in commercial aspheric intraocular lenses (IOLs). METHODS: Numerical simulations were performed using the wavefront data of 139 right eyes implanted with a spherical Morcher 89A ("Bag-in-the-Lens") IOL. Simulations were done for spherical, constant aspherical and SA-free IOLs, as well as for the customized selection method. RESULTS: Constant aspherical IOLs bought 49.6% of the eyes to a targeted postoperative SA value +/- 0.05 microm, while zero-SA IOLs brought 61.2% of the eyes to this range. However with customized selection 95% of the eyes could be brought to this target, resulting in more control over the postoperative spherical aberration. If no aspherical correction was used, only 8.6% of the eyes could reach the set target. CONCLUSION: These numerical results suggest that IOLs with an asphericity as a function of IOL power, supplemented by a customized selection from a number of fixed SA values according to preoperative corneal SA, may provide sufficient control over the postoperative SA. Given the surgeon centration possibility of the Bag-in-the-Lens IOL used in this study, as well as its centration stability, this is an ideal lens to implement the customized selection method.

[Secondary toric intraocular lens implantation in pseudophakic eyes. The add-on IOL system]. / Sekundäre torische Intraokularlinsenimplantation in pseudophake Augen. Das "Add-on"-IOL-System.

The last 2 years have seen the development of toric IOL especially designed for implantation in the ciliary sulcus for correction of corneal astigmatism in pseudophakic eyes. The term 'add-on IOL systems' is becoming more and more widely accepted for the lenses used in this procedure. The main indications for it are regular corneal astigmatism in pseudophakic eyes, for example following perforating keratoplasty, or when corneal scarring is present following trauma or infection. The implantation is a simple atraumatic procedure carried out under topical anaesthesia through a sclerocorneal incision. When the IOL is oriented along the steepest corneal meridian with the aid of corneal topographical monitoring, reliable and lasting correction of even extremely pronounced astigmatism is possible. Although this procedure has proved to be very efficient over a long follow-up period in small patient populations, reports of later adjustment of the rotation of toric add-on IOLs must be tested in further trials, especially in the case of simultaneous implantation of endocapsular IOLs in both eyes. Nonetheless, the possibility of later correction and reversibility of the intervention are further advantages of this lens system. As well as the correction of astigmatism in pseudophakic eyes the add-on IOL system also offers the option of treating pseudophakic eyes with sulcus-fixed multifocal lenses in the context of refractive interventions, e.g. as a secondary procedure.

Prospective randomised double-masked trial of bilateral multifocal, bifocal or monofocal intraocular lenses.

AIMS: To evaluate the functional effect of bilateral implantation of two different multifocal intraocular lenses (IOL) compared with the standard monofocal IOL. METHODS: Sixty-nine patients were recruited into a prospective, double-masked, randomised, controlled trial at a single hospital in the United Kingdom. Sixty completed follow-up; 16 implanted with monofocal IOLs, 29 with AMO 'ARRAY' multifocal IOLs and 15 with Storz 'TRUEVISTA' bifocal IOLs. Phacoemulsification and IOL implantation was performed to a standardised technique in both eyes within a 2-month period. The main outcome measures were distance and near visual acuity, depth of field and validated assessment of subjective function (TyPE questionnaire). RESULTS: naided distance acuity was good, and equivalent across the three groups. Corrected distance acuity was significantly lower in the bifocal group. Patients with multifocal and bifocal IOLs could read smaller absolute print size than those in the monofocal group (P = 0.05), but at a closer reading distance such that mean unaided near acuity was equal in the three groups. Corrected near acuity was significantly higher in the monofocal control group (P < 0.05). Depth of field was increased in multifocal (P = 0.06) and bifocal (P = 0.004) groups. Overall visual satisfaction was equal in the three groups, while near visual satisfaction was higher in the multifocal group than the monofocal (P = 0.04). Spectacle independence was not seen in the monofocal group, but was achieved in 28% of multifocal IOL patients and 33% of bifocal patients (P < 0.001). Adverse symptoms such as glare and haloes were significantly more bothersome with multifocal (not bifocal) IOLs than monofocals (P = 0.01). CONCLUSIONS: Multifocal and bifocal IOLs improved unaided near vision performance, with around one in three patients becoming spectacle-independent. The main adverse effect was an increased incidence of subjective glare and haloes in the multifocal IOL group.

[A new predictive formula for anterior chamber depth for pseudophakia].

PURPOSE: To develop a new predictive formula of the anterior chamber depth(ACD) of the pseudophakic eyes for more accurate intraocular lens(IOL) power calculation with the Ray Tracing method. METHODS: We studied a series of 149 phacoemulsificated eyes with capsulorhexis and in-the-bag fixation of IOL. ACD was measured with a Jaeger type depth measuring unit which was attached to a slit-lamp biomicroscope. We developed the formula with 3 variables: preoperative anterior corneal curvature with keratometer, and ACD and crystalline lens thickness with preoperative ultrasonography. We named the derived formula "formula H". We compared formula H with Olsen's predictive formula for the ACD(Olsen 92, Olsen 95). RESULTS: Mean absolute error between the predicted and postoperatively measured ACD was 0.174 +/- 0.133, 0.280 +/- 0.235, 0.229 +/- 0.200 mm in formula H, Olsen 92, and Olsen 95, respectively. Formula H was significantly more accurate than both Olsen formulas(p < 0.001, p < 0.05, respectively). CONCLUSIONS: The accuracy of IOL power calculation can be improved with the new formula using the Ray Tracing method, using the new ACD predictve formula.

CT and MR imaging of contact lenses and intraocular lens implants.

To study the image of contact lenses and intraocular lens implants in vitro and in vivo by CT and MRI prospectively. Soft and rigid contact lenses can be seen in vitro in both methods but in vivo imaging was insensitive. Intraocular lens implants were detected in CT and MRI in vitro. In vivo, intra ocular lens implants were detected in all CT, but were harder to detect by the MRI.

[Results of implantation of transsclerally sutured posterior chamber lenses in combination with penetrating keratoplasty]. / Implantation skleranahtfixierter Hinterkammerlinsen in Kombination mit perforierender Keratoplastik.

UNLABELLED: Implantation of transsclerally sutured posterior chamber lenses is one possibility of surgical visual rehabilitation of eyes with pseudophacic or aphacic bullous keratopathy without zonular-capsular support. We analyzed the results and complications of the surgical procedures performed in our institution. PATIENTS AND METHODS: Out of 1567 penetrating keratoplasties and 220 transsclerally sutured posterior chamber lenses that were performed at our institution between 1991 and 1996, patients that underwent penetrating keratoplasty and sutured posterior chamber lens implantation in whom sufficient clinical information was available were selected and analyzed in a retrospective, nonselective study. Surgery was performed by a total of four surgeons and included anterior vitrectomy, inside-out suturing and synechiolysis if necessary. Detailed pre- and intraoperative data, postoperative course and complications were recorded and analyzed. RESULTS: A total of 96 eyes were analyzed (patient age 17-92 years, 49 male, 46 female). Penetrating keratoplasty was performed for pseudophacic (63) oder aphacic (15) bullous keratopathy or for corneal scars following penetrating injury (18). Mean follow-up was 22 months. In 82 of 96 eyes, visual acuity improved following surgery. Complications included rhegmatogenous retinal detachment in 4 eyes, graft rejection in 5 eyes, secondary angle-closure glaucoma caused by preexisting anterior synechiae in 7 eyes, and persisting cystoid macular edema in 19 eyes. Luxation or subluxation of the IOL and endophthalmitis were not observed in any of the patients. CONCLUSION: Implantation of transsclerally sutured posterior chamber lenses appears to be a safe procedure and is considered by us to be the procedure of choice to correct aphacia during penetrating keratoplasty in eyes with absent zonular-capsular support. The majority of postoperative complications is apparently caused by preexisting problems related to previous surgery and/or trauma, such as peripheral anterior synechiae, vitreous incarceration or cystoid macular edema.