Visual and optical performance of the Akreos Adapt Advanced Optics and Tecnis Z9000 intraocular lenses: Swedish multicenter study

PURPOSE

To compare the subjective visual and objective optical performance of 2 aspherical intraocular lenses (IOLs), the Akreos Adapt Advanced Optics (AO) (Bausch & Lomb, Inc.) and the Tecnis Z9000 (Advanced Medical Optics, Inc.).

SETTING

Four university hospitals in Sweden.

METHODS

This study comprised 80 patients, 20 each from 4 university hospital centers in Sweden. All patients had bilateral clear corneal phacoemulsification with implantation of an Akreos Adapt AO IOL in 1 eye and Tecnis Z9000 IOL in the other eye according to a randomization protocol. Preoperatively, 90% contrast Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity was measured and the mesopic pupil sizes were determined. Ten to 12 weeks postoperatively, 12.5% and 90% contrast ETDRS visual acuities and photopic and mesopic Functional Acuity Contrast Test chart contrast sensitivities were determined. Wavefront analysis was performed with the Zywave II aberrometer (Bausch & Lomb, Inc.), and a questionnaire on the subjective quality of vision was completed by each patient.

RESULTS

The Akreos AO IOL and Tecnis Z9000 IOL produced similar high- and low-contrast visual acuities as well as photopic and mesopic contrast sensitivities. The Tecnis Z9000 IOL resulted in lower spherical aberrations of the eye (mean 0.05 +/- 0.13 microm versus 0.35 +/- 0.13 microm root mean square, 6.0 mm pupil) (P<.001); however, the Akreos AO IOL provided a larger depth of field (mean 1.22 diopter [D] +/- 0.48 [SD] versus 0.86 +/- 0.50 D, 6.0 mm pupil) (P<.001). Patient satisfaction was generally high, although 68.8% of the patients reported some type of visual disturbance postoperatively. Twenty-eight percent of patients reported better subjective visual quality in the Akreos AO eye and 14%, in the Tecnis Z9000 eye (P<.0001). Accordingly, 33% perceived more visual disturbances in the Tecnis Z9000 eye and 11%, in the Akreos AO eye (P<.0001).

CONCLUSIONS

Maximum reduction of spherical aberration did not maximize subjective visual quality. The higher perceived quality of vision with the Akreos AO IOL could be because of differences in depth of field, IOL material, or IOL design.

Epithelial ingrowth after LASIK treatment with scraping and phototherapeutic keratectomy

PURPOSE

To evaluate the effect of phototherapeutic keratectomy (PTK) in combination with manual scraping when removing epithelial ingrowth under a LASIK flap.

MATERIAL AND METHODS

Three patients, who had undergone several surgeries following LASIK in order to remove epithelial ingrowth that was threatening vision, were treated with a flap lift, manual abrasion and PTK. The PTK was performed on both the stromal and the flap side with the aim of eliminating the threat and improving vision. Two patients underwent primary surgery to remove epithelial ingrowth with manual abrasion and PTK. The influence on vision, topography and cell recurrences was evaluated.

RESULTS

Uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA) improved in four cases and remained good in the fifth case. The refraction did not change significantly. Topography disclosed changes in the irregular astigmatism, explaining the improved BSCVA. Central epithelial ingrowth did not recur, whereas peripheral ingrowth did. The peripheral ingrowth did not progress, except in case 1, where a cyst formed that required surgery.

CONCLUSIONS

It is our belief that adding PTK to manual scraping improves the prognosis for eyes with epithelial ingrowth. It is mainly the central ingrowth that is positively affected. Improved adhesion between the stroma and the flap is one possible explanation.

Lipofuscin accumulation in cultured retinal pigment epithelial cells reduces their phagocytic capacity

PURPOSE

Retinal pigment epithelial (RPE) cells slowly accumulate lipofuscin pigment within their acidic vacuolar apparatus as a result of extra- and/or intralysosomal oxidative alterations of phagocytosed photoreceptor outer segments (POS) with consequent imperfect degradation of these structures. In old age, lipofuscin accumulation may become quite substantial. It has been suggested that pronounced accumulation of lipofuscin is related to decreased RPE function and, possibly, to age-related macular degeneration. The aim of the present investigation was to study whether heavy loading with lipofuscin of RPE acidic lysosomes would affect the further phagocytic ability of the cells.

METHODS

In the first section of the investigation, cultures of rabbit RPE cells were exposed daily to bovine UV-irradiated POS (artificial lipofuscin) for 4 weeks, resulting in a pronounced lipofuscin accumulation of the cells. Fluorescent latex beads (labelled with a red fluorophore) were added to unloaded control cultures at O and 4 weeks after their establishment, and to lipofuscin loaded cells after 4 weeks of feeding with artificial lipofuscin. Cellular amounts of lipofuscin, and their phagocytotic activity, were quantified by static fluorometry measuring lipofuscin-specific and red bead-specific fluorescence, respectively. The intracellular location of the beads was verified by confocal laser scanning microscopy.

RESULTS

Unloaded, and thus almost lipofuscin-free, control cells exposed to latex beads showed numerous cytoplasmic particles emitting reddish fluorescence, while few particles were taken up by cells initially loaded with artificial, POS-derived, lipofuscin. Measurement of the latex bead-specific fluorescence showed significantly (p < 0.001) higher levels in unloaded control cells than in lipofuscin-loaded ones. In the second part of the investigation, unloaded control cultures and lipofuscin-loaded cultures were exposed to native bovine Texas Red-X-labelled POS 4 weeks after the establishment of the cultures. Unloaded control cells showed a large number of cytoplasmic POS emitting reddish fluorescence, while fewer POS were phagocytosed by cells loaded with artificial lipofuscin. Measurement of the Texas Red-X-specific fluorescence, thus quantifying the phagocytic ability of the cells, showed significantly (p < 0.001) higher levels in control cells than in lipofuscin-loaded ones.

CONCLUSIONS

Severe lipofuscin accumulation of RPE cells appears to result in a greatly decreased phagocytic capacity. The resulting reduction in ability to cope with the needs of the overlying photoreceptor cells, in order to eliminate the obsolete tips of their POS, may well be of significance in the development of age-related macular degeneration.