[Optical quality after refractive corneal surgery]

Trifocal Intraocular Lens Implantation to Treat Visual Demands in Various Distances Following Lens Removal

PURPOSE

To evaluate visual and refractive outcomes after implantation of a trifocal intraocular lens (IOL).

DESIGN

Prospective, nonrandomized noncomparative case series.

METHODS

setting: Department of Ophthalmology, Goethe University, Frankfurt/Germany. patient or study population: Twenty-seven patients (54 eyes) who had bilateral implantation of the AT LISA trifocal IOL (AT LISA tri839MP; Carl Zeiss Meditec, Jena, Germany) pre-enrollment. Exclusion criteria were previous ocular surgeries excluding cataract surgery and refractive lens exchange, irregular corneal astigmatism of >1.5 diopter, and ocular pathologies or corneal abnormalities. Intervention or Observation Procedure(s): Postoperative examination at 1 and 3 months included manifest refraction; monocular and binocular uncorrected (UCVA) and distance-corrected (DCVA) visual acuity in 4 m, 80 cm, and 40 cm; slit-lamp examination; and tomography. At 3 months defocus testing, binocular contrast sensitivity (CS) under photopic and mesopic conditions, and a questionnaire on subjective quality of vision, optical phenomena, and spectacle independence were performed.

MAIN OUTCOME MEASURE(S)

Three-months-postoperative monocular and binocular UCVA and DCVA in 4 m, 80 cm, and 40 cm (logMAR); defocus curve; CS; and quality-of-vision questionnaire results.

RESULTS

Mean spherical equivalent was 0.05 ± 0.32 D 3 months postoperatively. Binocular UCVA at distance, intermediate, and near was -0.1 ± 0.1 logMAR, 0.0 ± 0.1 logMAR, and 0.0 ± 0.1 logMAR, respectively. Despite some optical phenomena, 92% of patients would choose the same IOL again.

CONCLUSION

Evaluation of a trifocal IOL showed good VA (0.1 logMAR or better) at far, intermediate, and near distance; high patient satisfaction despite some optical phenomena; and high spectacle independence 3 months postoperatively.

Analysis of optical side-effects of fs-laser therapy in human presbyopic lens simulated with modified contact lenses

BACKGROUND

In a single-blinded study, optical side-effects of a potential femtosecond (fs)-laser therapy in presbyopic human lenses were tested. Simulation of this therapy was carried out by applying fs-laser patterns into standard contact lenses (CL).

METHODS

In the first part of the study, the influence of the numerical aperture on optical side-effects was investigated by comparing a typical fs-LASIK configuration to a fs-presbyopia treatment (n = 11). The second part focused on a possible improvement of visual performance by comparing a regular grid pattern to a randomly chosen spacing of the laser spots (n = 16). Visual acuity was measured with ETDRS charts, contrast sensitivity with F.A.C.T. charts and mesopic vision with Mesotest II. Forward scattered light was measured with the C-Quant (both instruments: Oculus Optikgeräte GmbH, Germany). A questionnaire detected subjective quality of vision. Differences between laser-treated and untreated CL and among the modifications were analyzed.

RESULTS

The laser-treated and standard CL indicated no significant difference in visual acuity, contrast sensitivity and mesopic vision without glare. While wearing modified lenses with a regular grid, quality of vision decreased significantly by means of mesopic vision with glare and subjective straylight. These modifications also caused an impairment of subjective quality of vision. In contrast, there was no significant difference between the random pattern and standard CL.

CONCLUSION

The increase of optical side-effects was reproducibly dependent on the geometry of the laser-structure. A randomized grid induced the least limitation. The study results are useful for planning possible laser-patterns in fs-laser therapy of the presbyopic lens.

Higher-order aberrations after implantation of iris-fixated rigid or foldable phakic intraocular lenses

PURPOSE

To evaluate higher-order aberrations (HOAs) after implantation of Artiflex phakic intraocular lenses (pIOLs).

SETTING

Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands.

METHODS

This retrospective comparative case series comprised 27 eyes (14 patients) that had Artiflex pIOL implantation and 22 eyes (13 patients) that had Artisan pIOL implantation. Refractive data, pupil size, IOL decentration, and HOA values were recorded and compared. Laboratory analysis was performed. Follow-up was 1 year.

RESULTS

In the Artiflex group, the mean spherical equivalent (SE) changed from -9.95 diopters (D) +/- 1.43 (SD) (range -6.75 to -12.13 D) to -0.30 +/- 0.53 D (range -1.94 to 0.56 D). Postoperatively, trefoil-y increased (increase factor 1.73) and spherical aberration decreased (increase factor 0.55). The mean pIOL decentration was 0.24 +/- 0.12 mm; 96.3% were decentered 0.5 mm or less. There was a significant correlation between pIOL decentration and postoperative spherical aberration and coma-y. In the Artisan group, the mean SE changed from -9.90 +/- 2.74 D (range -4.00 to -14.50 D) to -0.20 +/- 0.42 D (range -0.75 to 0.50 D). Postoperatively, trefoil-y and spherical aberration increased (increase factors 3.32 and 6.84, respectively). Laboratory analysis confirmed the negative and positive spherical aberration profile of the Artiflex pIOL and Artisan pIOL, respectively.

CONCLUSIONS

Artiflex pIOL implantation decreased spherical aberration, while Artisan pIOL implantation increased spherical aberration. Trefoil-y increased in both groups. These changes might be explained by incision size differences in relation to trefoil and differences in optic design in relation to spherical aberration.

[Apodized diffractive optic. New concept in multifocal lens technology]

As a consequence of improvement in intraocular lens (IOL) technology and the wish for presbyopia correction, modern multifocal IOLs are being implanted increasingly more often. The apodized diffractive optic represents a new design among multifocal IOLs. A comprehensive description of this principle with a review of current literature facilitates the understanding and correct application in IOL surgery.

[Application of wavefront analysis in clinical and scientific settings. From irregular astigmatism to aberrations of a higher order--Part II: examples]

In recent years, wavefront analysis has ceased to be purely a laboratory application and emerged as a method used in ophthalmological diagnosis. This development has been promoted mainly by the widespread use of wavefront-guided LASIK (laser in situ keratomileusis). However, aberrometry is still not a common diagnostic technique, and for many ophthalmologists interpretation of the results is difficult. The second part of this serial paper reviews findings that are relevant for the ophthalmological community and highlights current scientific applications in this area.

[Satisfaction with penetrating keratoplasty. Results of a questionnaire census]

BACKGROUND

Penetrating keratoplasty (PKP) is commonly referred to as the most successful transplantation procedure in medicine. This appraisal, however, is currently poorly supported by evidence. The aim of our study was to collect data on patient satisfaction with PKP as well as to analyze factors predisposing to dissatisfaction.

PATIENTS AND METHODS

In the years 1988-2002 a total of 3,219 PKPs were performed on 2,981 patients. These patients were sent a questionnaire. The items pertained to subjective assessment of visual quality as compared to the situation before PKP and about regretting the PKP.

RESULTS

The questionnaire was answered by 1,142 patients (59% of the traceable persons). The mean follow-up was 3.3+/-2.9 years. Indications for PKP were Fuchs' endothelial dystrophy (26%), keratoconus (23%), bullous keratopathy (15%), and further indications (36%). For these groups, best corrected visual acuity improved by more than two lines in 51, 80, 42, and 50%, respectively. The percentage of subjective improvement of vision was 73, 78, 47, and 63%. The percentage of regretting the PKP was 12, 4, 27, and 10%, respectively. All differences were highly statistically significant. Significant influencing factors on regretting the PKP were (inversely sorted for relevance): repeat graft failure, bullous keratopathy, contact lens wear, paresthesia, removal of running sutures, and patient age.

CONCLUSIONS

General satisfaction with PKP is high. An important exception is bullous keratopathy, most likely due to accompanying morbidity (e.g., cystoid macular edema).