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Intraocular lens-edge design and material factors contributing to posterior-capsulotomy rates: comparing Hoya FY60aD, PY60aD, and AcrySof SN60WF.

Morgan-Warren PJ, Smith JA - Clin Ophthalmol (2013)

Bottom Line: Twenty-eight of 315 eyes (8.9%) implanted with the FY60AD underwent LPC by 2 years, compared to eleven of 254 (4.3%) with the newer sharp square-edged PY60AD and ten of 696 (1.4%) with the one-piece SN60WF (P < 0.05, Chi-squared analyses).The newer, sharper-edged Hoya PY60AD IOL has a lower LPC rate than the Hoya FY60AD IOL at 2 years post-cataract surgery.Variations in IOL-edge design and material effect may have contributed to the different rates observed.

View Article: PubMed Central - PubMed

Affiliation: Victoria Eye Unit, Hereford County Hospital, Hereford, UK.

ABSTRACT

Purpose: To compare neodymium-doped yttrium aluminum garnet laser posterior capsulotomy (LPC) rates between the Hoya FY60AD, Hoya PY60AD, and Alcon AcrySof SN60WF intraocular lenses (IOLs) after routine cataract surgery.

Methods: In this retrospective comparative study, patients undergoing uncomplicated cataract surgery over a 3-year period were included, and those subsequently undergoing LPC were identified from laser clinic records. LPC rates at 2 years postoperatively were compared between the round-edged Hoya FY60AD, the newer sharp-edged Hoya PY60AD three-piece IOLs, and the one-piece AcrySof SN60WF IOL.

Results: A total of 1,265 cataract operations were included, and 49 eyes (3.9%) underwent LPC within 2 years of surgery. Twenty-eight of 315 eyes (8.9%) implanted with the FY60AD underwent LPC by 2 years, compared to eleven of 254 (4.3%) with the newer sharp square-edged PY60AD and ten of 696 (1.4%) with the one-piece SN60WF (P < 0.05, Chi-squared analyses).

Conclusions: The newer, sharper-edged Hoya PY60AD IOL has a lower LPC rate than the Hoya FY60AD IOL at 2 years post-cataract surgery. The one-piece AcrySof SN60WF has a lower LPC rate than both the three-piece Hoya IOLs in the same time period postoperatively. Variations in IOL-edge design and material effect may have contributed to the different rates observed.

No MeSH data available.


Related in: MedlinePlus

Graphical representation of the assessment of intraocular lens (IOL)-edge sharpness, based on measurement of the area deviating from a perfect square on electron photomicrographs (see text). in these stylized IOLs drawn in section, IOL1 has a smaller area measurement (AM1) than IOL2 (AM2), and therefore has a squarer edge.
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f2-opth-7-1661: Graphical representation of the assessment of intraocular lens (IOL)-edge sharpness, based on measurement of the area deviating from a perfect square on electron photomicrographs (see text). in these stylized IOLs drawn in section, IOL1 has a smaller area measurement (AM1) than IOL2 (AM2), and therefore has a squarer edge.

Mentions: The importance of IOL-edge structure is widely accepted, and the evidence in favor of a square posterior optic edge in reducing PCO and LPC requirement is overwhelming. A square edge on the posterior IOL surface provides a barrier to LEC migration by inducing a capsular bend where it is in contact with the IOL edge.13–17 A recent systematic review found significantly lower PCO scores in sharp-edged IOLs compared to round-edged models, although no clear differences between IOL materials.18 However, not all square edges are the same, as edge sharpness is subject to variation between IOL models. Using scanning electron microscopy and computer-aided imaging, it is possible to determine the area of the lateral-posterior IOL edge deviating from a perfect square, demonstrating a large variation both between IOL designs and between different powers of the same design (Figure 2). Area-measurement values for hydrophilic acrylic IOLs as a group are higher than for hydrophobic acrylic or silicone IOLs, indicating a more rounded edge in the former and suggesting that differences reported between IOL materials may actually be related in part to IOL-edge sharpness.4,19 In addition, a prospective, single surgeon, fellow-eye comparison study found higher PCO rates and poorer visual acuity with the Hoya AF-1 YA-60BB IOL compared to the Alcon AcrySof SN60AT, and electron microscopy showed a much sharper posterior-edge profile in the Alcon IOL compared to the Hoya IOL.20 This type of evaluation can help manufacturers optimize their IOL optic edges. For example, Hoya Surgical Optics have recently altered their IOL-polishing process in order to sharpen the posterior edge of their IOLs, reducing the area of deviation from a perfect square from 329.7 μm2 in the older FY60AD model to a sharper 39.1 μm2 in the newer PY60AD and 251 IOLs, the latter now amongst the sharpest square-edge profiles of any commercially available IOL.19 Our study supports the validity of this approach, with fewer patients requiring LPC after implantation with the sharper-edged PY60AD compared to the older FY60AD by 2 years after surgery.


Intraocular lens-edge design and material factors contributing to posterior-capsulotomy rates: comparing Hoya FY60aD, PY60aD, and AcrySof SN60WF.

Morgan-Warren PJ, Smith JA - Clin Ophthalmol (2013)

Graphical representation of the assessment of intraocular lens (IOL)-edge sharpness, based on measurement of the area deviating from a perfect square on electron photomicrographs (see text). in these stylized IOLs drawn in section, IOL1 has a smaller area measurement (AM1) than IOL2 (AM2), and therefore has a squarer edge.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3755701&req=5

f2-opth-7-1661: Graphical representation of the assessment of intraocular lens (IOL)-edge sharpness, based on measurement of the area deviating from a perfect square on electron photomicrographs (see text). in these stylized IOLs drawn in section, IOL1 has a smaller area measurement (AM1) than IOL2 (AM2), and therefore has a squarer edge.
Mentions: The importance of IOL-edge structure is widely accepted, and the evidence in favor of a square posterior optic edge in reducing PCO and LPC requirement is overwhelming. A square edge on the posterior IOL surface provides a barrier to LEC migration by inducing a capsular bend where it is in contact with the IOL edge.13–17 A recent systematic review found significantly lower PCO scores in sharp-edged IOLs compared to round-edged models, although no clear differences between IOL materials.18 However, not all square edges are the same, as edge sharpness is subject to variation between IOL models. Using scanning electron microscopy and computer-aided imaging, it is possible to determine the area of the lateral-posterior IOL edge deviating from a perfect square, demonstrating a large variation both between IOL designs and between different powers of the same design (Figure 2). Area-measurement values for hydrophilic acrylic IOLs as a group are higher than for hydrophobic acrylic or silicone IOLs, indicating a more rounded edge in the former and suggesting that differences reported between IOL materials may actually be related in part to IOL-edge sharpness.4,19 In addition, a prospective, single surgeon, fellow-eye comparison study found higher PCO rates and poorer visual acuity with the Hoya AF-1 YA-60BB IOL compared to the Alcon AcrySof SN60AT, and electron microscopy showed a much sharper posterior-edge profile in the Alcon IOL compared to the Hoya IOL.20 This type of evaluation can help manufacturers optimize their IOL optic edges. For example, Hoya Surgical Optics have recently altered their IOL-polishing process in order to sharpen the posterior edge of their IOLs, reducing the area of deviation from a perfect square from 329.7 μm2 in the older FY60AD model to a sharper 39.1 μm2 in the newer PY60AD and 251 IOLs, the latter now amongst the sharpest square-edge profiles of any commercially available IOL.19 Our study supports the validity of this approach, with fewer patients requiring LPC after implantation with the sharper-edged PY60AD compared to the older FY60AD by 2 years after surgery.

Bottom Line: Twenty-eight of 315 eyes (8.9%) implanted with the FY60AD underwent LPC by 2 years, compared to eleven of 254 (4.3%) with the newer sharp square-edged PY60AD and ten of 696 (1.4%) with the one-piece SN60WF (P < 0.05, Chi-squared analyses).The newer, sharper-edged Hoya PY60AD IOL has a lower LPC rate than the Hoya FY60AD IOL at 2 years post-cataract surgery.Variations in IOL-edge design and material effect may have contributed to the different rates observed.

View Article: PubMed Central - PubMed

Affiliation: Victoria Eye Unit, Hereford County Hospital, Hereford, UK.

ABSTRACT

Purpose: To compare neodymium-doped yttrium aluminum garnet laser posterior capsulotomy (LPC) rates between the Hoya FY60AD, Hoya PY60AD, and Alcon AcrySof SN60WF intraocular lenses (IOLs) after routine cataract surgery.

Methods: In this retrospective comparative study, patients undergoing uncomplicated cataract surgery over a 3-year period were included, and those subsequently undergoing LPC were identified from laser clinic records. LPC rates at 2 years postoperatively were compared between the round-edged Hoya FY60AD, the newer sharp-edged Hoya PY60AD three-piece IOLs, and the one-piece AcrySof SN60WF IOL.

Results: A total of 1,265 cataract operations were included, and 49 eyes (3.9%) underwent LPC within 2 years of surgery. Twenty-eight of 315 eyes (8.9%) implanted with the FY60AD underwent LPC by 2 years, compared to eleven of 254 (4.3%) with the newer sharp square-edged PY60AD and ten of 696 (1.4%) with the one-piece SN60WF (P < 0.05, Chi-squared analyses).

Conclusions: The newer, sharper-edged Hoya PY60AD IOL has a lower LPC rate than the Hoya FY60AD IOL at 2 years post-cataract surgery. The one-piece AcrySof SN60WF has a lower LPC rate than both the three-piece Hoya IOLs in the same time period postoperatively. Variations in IOL-edge design and material effect may have contributed to the different rates observed.

No MeSH data available.


Related in: MedlinePlus