Anterior chamber depth and change in axial intraocular lens position after cataract surgery with primary posterior capsulorhexis and posterior optic buttonholing

Postoperative intraocular lens stability following cataract surgery with or without primary posterior continuous curvilinear capsulorrhexis: an intra-individual randomized controlled trial

PURPOSE

To evaluate the effect of primary posterior continuous curvilinear capsulorrhexis (PPCCC) on the positional stability of IOLs.

METHODS

This study is a prospective intra-individual comparative randomized controlled trial including 31 patients (62 eyes). Eyes of the same patient were randomly assigned to the PPCCC group (18 right eyes and 13 left eyes) or group without PPCCC (NPCCC group). Eyes in both groups were implanted with a one-piece foldable hydrophobic acrylic IOL via routine cataract surgery. Patients in the PPCCC group underwent additional manual PPCCC before IOL implantation. Examinations were performed 1 day, 1 week, 1 month and 3 months postoperatively. IOL tilt (x, y), decentration (x, y), anterior chamber depth (z) and refractive prediction error data were collected and analyzed with Pentacam.

RESULTS

Postoperatively, the range of IOL position change over 3 months in PPCCC group was comparable to NPCCC group, which indicated smaller value in every tilt and decentration index. PPCCC eyes showed comparable tilt and decentration with NPCCC eyes in this study endpoint: mean tilt (x, y), decentration (x, y) and anterior chamber depth (ACD) were 1.04 ± 0.56°, 0.90 ± 0.64°, 0.239 ± 0.140 mm, 0.233 ± 0.133 mm and 4.01 ± 0.32 mm, respectively, in the PPCCC group vs. 1.09 ± 0.76°, 1.10 ± 0.82°, 0.252 ± 0.153 mm, 0.244 ± 0.155 mm and 4.01 ± 0.38 mm, respectively, in the NPCCC group. Refractive prediction error in the PPCCC group demonstrated a mild hyperopic shift vs. the NPCCC group (0.13 ± 0.50 vs. 0.05 ± 0.39; p = 0.208), and corrected distance visual acuity (CDVA) did not differ between the two groups (0.027 ± 0.014 vs. 0.059 ± 0.185; p = 0.377).

CONCLUSIONS

Comparable IOL tilt, decentration, ACD and refractive prediction error were observed in PPCCC eyes with that underwent routine cataract surgery. Little IOL position fluctuation and good visual acuity were shown in PPCCC group over time.

TRAIL REGISTRATION

The study was registered at the Chinese Clinical Trial Register Center on May 27th, 2020 (protocol code ChiCTR2000033304, 27/05/2020).

Intraocular lens tilt and decentration after cataract surgery with and without primary posterior continuous curvilinear capsulorhexis

PURPOSE

To evaluate intraocular lens (IOL) tilt and decentration and their effects on higher-order aberrations (HOAs) after cataract surgery with and without primary posterior continuous curvilinear capsulorhexis (PPCCC).

SETTING

Fujian Provincial Hospital, Fujian, China.

DESIGN

Prospective, intraindividual, randomized, comparative clinical trial.

METHODS

64 eyes of 32 patients with age-related cataract who underwent bilateral cataract surgery and IOL implantation were enrolled in this study. In randomized order, all patients had phacoemulsification cataract surgery with PPCCC in 1 eye (PPCCC group) and routine cataract surgery in the contralateral eye (NPCCC group). IOL decentration, tilt, HOAs, modulation transfer function, and point spread function were measured at 1 day, 1 week, 1 month, and 3 months after surgery using OPD-Scan III.

RESULTS

52 eyes of 26 patients were available for analysis. The mean overall decentration in the NPCCC group was significantly higher than in the PPCCC group at 3 months (0.302 ± 0.157 mm vs 0.187 ± 0.099 mm, P < .001). Under 3 mm pupil, internal spherical aberration (SA) 1 day after surgery and coma 1 week after surgery were lower in the PPCCC group compared with the NPCCC group (0.15 ± 0.10 μm vs 0.30 ± 0.21 μm, P < .001, and 0.34 ± 0.18 μm vs 0.47 ± 0.31 μm, P = .03, respectively). IOL decentration was significantly correlated with ocular and internal coma, ocular and internal SA, and internal HOAs at 5 mm pupil ( R = 0.083 and R = 0.099, R = 0.650 and R = 0.613, and R = 0.418, respectively, all P < .01).

CONCLUSIONS

Less IOL decentration was observed in the PPCCC group at 3 months after surgery, indicating that PPCCC may result in better IOL centrality.

Three-dimensional assessment of posterior capsule-intraocular lens interaction with and without primary posterior capsulorrhexis: an intraindividual randomized trial

PURPOSE

To assess the morphologic and clinical features of posterior capsule-intraocular lens (IOL) interaction following cataract surgery with and without primary posterior continuous curvilinear capsulorrhexis (PPCCC) at a three-dimensional (3-D) level using Scheimpflug imaging.

METHODS

This prospective intraindividual randomized comparative study comprised 56 patients (112 eyes) with age-related cataract who had bilateral cataract surgery and hydrophobic acrylic IOLs implantation. In randomized order, cataract surgery with PPCCC was performed in 1 eye (PPCCC group), and the posterior capsule was left intact in the fellow eye (NPCCC group). Scheimpflug imaging containing 25 images distributed in 360° was taken 1 day, 1 week, 1 month, and 3 months postoperatively.

RESULTS

46 patients completed 3 months follow-up. Posterior capsule-IOL interaction can be morphologically classified into two types including complete adhesion and floppy shape in PPCCC group, and six types including full area wave, full area flat, concentric ring wave, concentric ring flat, sector, and complete adhesion in NPCCC group. The adhesion index (AI), defined as the proportion of complete adhesion of posterior capsule-IOL in 25 cross-section tomograms, was 0.45 ± 0.45, 0.79 ± 0.37, 0.92 ± 0.26 and 1.00 ± 0.00 in PPCCC group, while 0.05 ± 0.18, 0.41 ± 0.47, 0.87 ± 0.34, and 0.96 ± 0.21 in NPCCC group at 1 day, 1 week, 1 month and 3 months postoperatively, respectively (p = 0.001, 0.001, 0.338 and 0.151).

CONCLUSIONS

3-D Scheimpflug imaging was favorable in observing of posterior capsule-IOL interaction. Faster posterior capsule adhesion to the IOL was found in PPCCC group than in NPCCC group.

Three-Dimensional Assessments of Intraocular Lens Stability With High-Speed Swept-Source Optical Coherence Tomography

PURPOSE

To evaluate the effect of intraocular lens (IOL) optic overlapping on IOL stability and to determine the relationship between the capsulorhexis and IOL movement with the three-dimensional method of swept-source optical coherence tomography (SS-OCT).

METHODS

This study identified patients with age-related cataracts and divided them into two groups according to their anterior capsule and IOL optic relationship: total anterior capsule overlap (360°) and partial anterior capsule overlap (< 360°). Standard SS-OCT radial scanning was performed in all eyes at 1 day, 1 week, 1 month, and 3 months after cataract surgery, respectively. The obtained photographs were used for the postoperative position measurements of capsulorhexis and IOL after three-dimensional reconstruction.

RESULTS

This study included 46 eyes of 34 patients: total overlap group (n = 29) and partial overlap group (n = 17). The postoperative aqueous depth significantly decreased in the first week after surgery (P < .001). The IOL tilt was greater in the partial overlap group than that in the total overlap group (P = .014). The IOL moved significantly in the first week postoperatively (both P < .001). IOL decentration in the x-axis was greater in the partial overlap group than that in the total overlap group (P = .024). The IOL and capsulorhexis both moved sharply in the first week (both P < .05). The IOL moved consistently with the capsulorhexis in the 3 months after surgery (all P > .05).

CONCLUSIONS

The total overlap group showed better IOL centrality and stability. IOL movement may be driven by capsular bag contraction and fibrosis. Thus, it was demonstrated that postoperative IOL position and IOL performance were closely linked with proper size of central continuous curvilinear capsulorhexis. [J Refract Surg. 2020;36(6):388-394.].

The Impact of IOL Abbe Number on Polychromatic Image Quality of Pseudophakic Eyes

Purpose

The human eye exhibits large amounts (2.5 diopters) of longitudinal chromatic aberration (LCA). Its impact on polychromatic image quality, however, has been shown experimentally and by computer modeling to be small or absent. We hypothesized that modest changes in pseudophakic LCA created by higher and lower Abbe number materials will have little or no impact on polychromatic image quality in pseudophakic eyes.

Materials and Methods

Using published chromatic and monochromatic aberration data from pseudophakic eyes and higher and lower Abbe number materials (37 and 55), we computed monochromatic point spread functions for 21 wavelengths across the visible spectrum. After weighting by either the RGB spectra of a liquid crystal display or by a flat white spectrum, they were weighted by the human spectral sensitivity function (V_λ) before being added to generate polychromatic PSFs.

Results

In the absence of monochromatic aberrations, the reduced LCA due to higher Abbe number intraocular lens (IOL) materials resulted in a reduction of 0.08 diopters in the mean defocus generated by LCA. At the retinal plane, the higher Abbe number pseudophakic model produced improvements in polychromatic modulation transfer functions (MTFs) similar to those generated by a 0.05 diopter reduction in spherical defocus. When monochromatic aberrations were added to make the model more representative of actual pseudophakic eyes, the differences in image quality became sub-threshold for human vision or disappeared completely.

Conclusion

The anticipated gains in polychromatic image quality from employing higher Abbe number IOL materials with reduced LCA do not materialize in plausible aberrated models of pseudophakic eyes.

The influence of low signal-to-noise ratio of axial length measurement on prediction of target refraction, achieved using IOLMaster

Purpose

To evaluate the influence of low signal-to-noise ratio (SNR) of axial length measurement, achieved using IOLMaster, on prediction of target refraction.

Methods

A total of 131 eyes of 131 patients who underwent phacoemulsification with posterior chamber lens implantation were enrolled. Preoperative axial length measurements were performed with the IOLMaster 500 (Carl Zeiss Meditec, Germany); preoperative SNR values were used to divide the eyes into three groups (Group 1; SNR <10, Group 2; 10 ≤ SNR <50, Group 3; 50 ≤ SNR <100). One month and 6 months after cataract surgery, the manifest refraction spherical equivalents (MRSE) were measured. The mean numeric errors (MNE), the mean of the difference between postoperative MRSE, and preoperative target refraction, using the various intraocular lens (IOL) formulas, were calculated and compared among the three groups.

Results

One month after cataract surgery, postoperative MRSE was more hyperopic than preoperative target refraction, calculated by the Haigis formula in group 1, and by the SRK/T formula in group 2. After 6 months, for all formulas in group 1, there were significantly hyperopic results (approximately 0.35 diopter). Upon comparison of MNE among the three groups, group 1 was statistically significantly different from the other groups by Haigis formula.

Conclusions

When the SNR values in biometry, using IOLMaster, are <10, careful attention should be given to determining IOL power, as postoperative spherical equivalents are more hyperopic than preoperative target refraction by IOL formula.

The effects of different shapes of capsulorrhexis on postoperative refractive outcomes and the effective position of the intraocular lens in cataract surgery

BACKGROUND

To evaluate the effects of anterior capsular opening size on deviation from predicted refraction and the effective position of the intraocular lens (ELP) in cataract surgery.

METHODS

Nonrandomized clinical trial. Eighty patients (80 eyes) with simple age-related cataracts were treated from May 2018 to September 2018 at the Fourth Affiliated Hospital of China Medical University. All patients undergoing phacoemulsification received intraocular lens based on the voluntary principle. Forty eyes were implanted with the C-loop haptic intraocular lens (AMO Tecnis ZCB00) while the other 40 eyes were implanted with the plate haptic intraocular lens (CT ASPHINA 509 M). Follow-up visits were conducted postoperatively at 1 week, 1 month, and 3 months during which patients underwent refraction and data collection after pupil dilation, which included anterior segment photography and Scheimpflug imaging by Pentacam. The area, horizontal and vertical diameter of the capsulorrhexis, circularity, decentration, and package were analysed using the image analysis software Image-Pro-Plus 6.0,then evaluated the relationship between the different shapes of capsulorrhexis with deviation from predicted refraction and ELP in cataract surgery.

RESULTS

Deviation from predicted refraction and all of the parameters of capsulorrhexis were not correlative in the 509 M IOL group, however, in the Tecnis IOL group, while the deviation from predicted refraction and all of the capsulorrhexis parameters were not correlative at 1 week, the deviation from predicted refraction did correlate with capsulorrhexis area, horizontal diameter at 1 month (P = 0.029, P = 0.048), and with capsulorrhexis area, vertical diameter at 3 months (P = 0.03, P = 0.017). The ELP correlated with package in both groups postoperatively (r > 0, P < 0.05), but there is no other capsulorrhexis parameters correlated with ELP in the 509 M IOL group (all P > 0.05). For the Tecnis IOL group, the ELP and capsulorrhexis area were correlated at 1 week and 1 month, while the ELP and horizontal diameter, the ELP and vertical diameter were correlated at 1 week, but did not correlate with the other capsulorrhexis parameters in the Tecnis IOL group (all P > 0.05).

CONCLUSIONS

The shape of the capsulorrhexis has an effect on postoperative refractive outcomes and the effective position of the intraocular lens in cataract surgery, and plate haptic intraocular lenses have better refractive stability than C-loop haptic intraocular lenses.

TRIAL REGISTRATION

ChiCTR1800015638 ,2018-04-12.

Visual performance of the intraindividual implantation of a trifocal intraocular lens in the bag and a +4.0 D bifocal intraocular lens in the sulcus with optic capture created by femtosecond laser-assisted cataract surgery

At present, only one design is available for trifocal intraocular lens (IOL); unfortunately, this particular design is not suitable for implantation in the sulcus with optic capture when posterior capsule rupture (PCR) occurs. Although three-piece bifocal IOLs can be implanted in the sulcus, this form of IOL can be vulnerable to tilt and decentration, thus causing aberration and photopic phenomena, such as halos and glares. However, visual axis centered optic capture using femtosecond laser-assisted cataract surgery (FLACS) is able to manage such complex operations.

In the present study, we implanted a three-piece +4.0 D bifocal IOL into the sulcus of a patient who experienced PCR using optic capture and FLACS following the straightforward implantation of a one-piece trifocal IOL in the other eye. Defocus curves showed that the weakness of the trifocal IOL (nearest distances) was compensated for by the strength of the +4.0 D bifocal IOL, whereas the weakness of the +4.0 D bifocal IOL (middle distance) was compensated for by the strength of the trifocal IOL. Therefore, this combination provided the patient with a wider range of depth of focus. The contrast sensitivity in both eyes was within the normal range. Photopic phenomena were comparable with the bilateral implantation of the trifocal IOL. Anterior segment optical coherence tomography showed that tilt and decentration in the trifocal IOL implanted in the bag was significantly higher than the +4.0 D bifocal IOL implanted in the visual axis centered optic capture.

This case showed that the intraindividual implantation of a single-piece trifocal IOL in the bag and a three-piece +4.0 D bifocal IOL in the sulcus, using a combination of optic capture and FLACS, is promising particularly in cases of PCR and can provide a wider range of vision without losing visual quality.

Long-term changes in intraocular lens position and corneal curvature after cataract surgery and their effect on refraction

PURPOSE

To evaluate the role of intraocular lens (IOL) position shift and changes in corneal curvature on long-term refractive shift after cataract surgery.

SETTING

Rotterdam Ophthalmic Institute, Rotterdam, the Netherlands.

DESIGN

Prospective cohort study.

METHODS

Patients who had routine cataract surgery with implantation of a hydrophobic acrylic 1-piece IOL (Acrysof SA60AT) in the capsular bag were enrolled. Measurements were performed preoperatively and 1 month, 3 months, and 1 year postoperatively. Refraction was measured with the ARK-530A autorefractor. The IOL position and corneal curvature were measured with the Lenstar LS-900 biometer. The refractive effect of changes in IOL position and corneal curvature was calculated with a Gaussian optics-based thin-lens formula and correlated with the measured refractive shift.

RESULTS

The study group comprised 59 eyes of 59 patients. The median measured absolute refractive change was 0.25 diopter (D). The IOL position showed a statistically significant mean posterior shift of 0.033 mm ± 0.060 (SD) between 1 month and 1 year postoperatively (P < .01), of which the median calculated absolute refractive effect was 0.05 D. This did not correlate with the measured refractive shift (Pearson r = 0.10, P = .46). Natural fluctuations in corneal curvature caused a median calculated absolute refractive effect of 0.17 D, which correlated well with the measured refractive shift (Pearson r = .55, P < .001).

CONCLUSIONS

Long-term changes in refraction after cataract surgery resulted from natural fluctuations in corneal curvature rather than from IOL position shift. These fluctuations limit the accuracy with which the refractive outcome can be planned.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Primary posterior continuous curvilinear capsulorhexis combined with diffractive multifocal intraocular lens implantation

PurposeTo evaluate the effect of mild posterior capsule opacity (PCO) on visual acuity (VA) in eyes implanted with a diffractive multifocal intraocular lens (IOL) compared with a monofocal IOL, and the effect of posterior continuous curvilinear capsulorhexis (PCCC) combined with diffractive multifocal IOL implantation.MethodsFor the initial evaluation, we compared charge-coupled device (CCD) camera photographs taken through both a monofocal IOL-loaded model eye and a diffractive IOL-loaded model eye under the conditions of both with and without an opaque filter for the simulation of mild PCO. The clinical evaluation involved 20 patients who underwent bilateral implantation of the same diffractive multifocal IOL. In all 20 cases, PCCC was performed in 1 eye (PCCC group) and not performed in the fellow eye (NCCC group). Postoperative clinical results were then compared between the two groups.ResultsThe CCD photographs revealed that the diffractive IOL-loaded eye was more strongly affected by the simulated PCO than was the monofocal IOL-loaded eye. In the clinical setting, the PCCC group registered better results than NCCC group in distance and near VA, low-contrast VA, and contrast sensitivity testing.ConclusionsDiffractive multifocal IOLs tend to be more influenced by mild PCO than do monofocal IOLs, and PCCC prior to IOL implantation can contribute to the avoidance of this effect.

Chromatic aberration and polychromatic image quality with diffractive multifocal intraocular lenses

PURPOSE

To evaluate the impact of target distance on polychromatic image quality in a virtual model eye implanted with hybrid refractive-diffractive intraocular lenses (IOLs).

SETTING

School of Optometry, Indiana University, Bloomington, Indiana, USA.

DESIGN

Experimental study.

METHODS

A pseudophakic model eye was constructed by incorporating a phase-delay map for a diffractive optical element into a reduced eye model incorporating ocular chromatic aberration, pupil apodization, and higher-order monochromatic aberrations. The diffractive element was a monofocal IOL with a +3.2 diopter (D) diffractive power or 2 types of bifocal IOLs (nonapodized or apodized) with a +2.92 D addition (add) power. Polychromatic point-spread functions and image quality for white and monochromatic light were quantified for a series of target vergences, wavelengths, and pupil diameters using modulation transfer functions and image-quality metrics.

RESULTS

Ocular longitudinal chromatic aberration was largely corrected by the monofocal design and by both bifocal designs for near targets. In the bifocal design, add power and the ratio of distance:near image quality changed significantly with wavelength and pupil size. Also, image quality for distance was better with the apodized design.

CONCLUSIONS

Achromatization by the diffractive IOL provided significant improvement in polychromatic retinal image quality. Along with apodization and higher-order aberrations, it can significantly affect the near-distance balance provided by a diffractive multifocal IOL.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Effect of primary posterior continuous curvilinear capsulorrhexis with posterior optic buttonholing on pilocarpine-induced IOL shift

PURPOSE

To assess intraocular lens (IOL) shift along the visual axis induced by ciliary muscle contraction with pilocarpine after cataract surgery and to compare primary posterior continuous curvilinear capsulorrhexis (CCC) and posterior optic buttonholing with IOLs implanted in the bag.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

DESIGN

Clinical trial.

METHODS

Eyes with age-related cataract had cataract surgery with implantation of a nonaccommodating IOL (AF-1 YA-60BB). Surgery was performed with primary posterior CCC and posterior buttonholing in 1 eye (study eyes) and with conventional in-the-bag implantation in the contralateral eye (control eyes). After a minimum of 6 months postoperatively, the anterior chamber depth was assessed with partial coherence interferometry before and after application of pilocarpine 2.0% and, after a washout interval of 1 week, before and after the application of cyclopentolate 1.0%.

RESULTS

Forty eyes of 20 patients were enrolled. A slight backward shift of the IOL (+78 μm) in study eyes and in control eyes (+118 μm) was detected after pilocarpine application (both P<.05). No significant difference in IOL shift was found between study eyes and control eyes (P=.19).

CONCLUSIONS

Combined primary posterior CCC and posterior optic buttonholing did not affect IOL shift during pharmacologically stimulated ciliary muscle contraction compared with in-the-bag implanted IOLs. Capsule fibrosis diminished with primary posterior CCC but did not seem to be the only limiting factor in the accommodative IOL shift.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Posterior optic buttonholing prevents intraocular pressure peaks after cataract surgery with primary posterior capsulorhexis

BACKGROUND

The performance of a primary posterior capsulorhexis (PPC) with and without posterior optic buttonholing (POBH) may significantly influence the intraocular pressure (IOP) after cataract surgery in age-related cataract patients.

METHODS

The prospective randomized clinical study was performed at the department of Ophthalmology, Medical University of Vienna, Austria. Thirty consecutive cataract patients with bilateral same-day cataract surgery (60 eyes) under topical anesthesia were enrolled. In randomized order, cataract surgery with combined PPC/POBH was performed in one eye; in the other eye, cataract surgery was performed with PPC and in-the-bag implantation of the intraocular lens (IOL). Standardized IOP measurements by Goldmann applanation tonometry were performed preoperatively, 1, 2, 4, 6, 8 and 24 hours postoperatively, as well as 1 week and 1 month postoperatively.

RESULTS

During the first 24 hours after surgery, all IOP measurements were significantly lower in eyes with combined PPC/POBH when compared to eyes with solitary PPC (p < 0.001). No IOP peaks of more than 27 mmHg were observed with combined PPC/POBH. In contrast, in eyes with PPC and in-the-bag IOL implantation, seven patients had an IOP peak of more than 27 mmHg and four IOP peaks of more than 30 mmHg. One week and 1 month postoperatively, IOP measurements were statistically comparable, and no significant differences could be observed between the two groups (p > 0.05).

CONCLUSION

Postoperative IOP peaks after cataract surgery with sole PPC can be effectively prevented by the buttonholing of the IOL through the posterior capsulorhexis.

Intraocular lens stability and refractive outcomes after cataract surgery using primary posterior continuous curvilinear capsulorrhexis

PURPOSE

To evaluate the amount of intraocular lens (IOL) decentration and refractive changes after cataract surgery using posterior continuous curvilinear capsulorrhexis (PCCC).

DESIGN

Prospective comparative case series.

PARTICIPANTS

We included 86 eyes of 77 patients who had cataract surgery using PCCC (the PCCC group), and 79 eyes of 68 patients treated without PCCC (the control group).

METHODS

Foldable IOLs with polymethylmethacrylate haptics (VA-60BB, Hoya Corporation, Tokyo, Japan) were implanted in both groups. The best-corrected visual acuity (BCVA) was assessed. Automated refractokeratometry, Scheimpflug imaging (Pentacam; Oculus, Wetzlar, Germany), and slit-lamp photography with retroillumination were performed at each follow-up visit over 6 months. The axial shift of each IOL was measured as the distance between the corneal endothelium and the anterior surface of the IOL on Scheimpflug images. The horizontal shift was assessed as the distance between the geometric center of the IOL and the centers of the pupil and the limbus.

MAIN OUTCOME MEASURES

Best-corrected visual acuity, horizontal and axial shift of the IOL, and automated refraction.

RESULTS

There was no difference between the 2 groups in the mean BCVA before surgery and at any postoperative follow-up. The mean horizontal shift of the IOL after 6 months was 0.25 ± 0.14 mm for the pupil and 0.31 ± 0.17 mm for the limbus in the PCCC group (P = 0.315), and 0.26 ± 0.09 mm and 0.31 ± 0.13 mm, respectively, in the control group (P = 0.115). These were not different from the measurement on the postoperative day 1 (P = 0.515, P = 0.263, P = 0.421, and P = 0.875, respectively). At each follow-up visit over 6 months, there was no difference in the horizontal shift between the 2 groups (P > 0.05). The IOL shifted insignificantly in the PCCC group (-0.08 ± 0.24 mm anterior shift), but the shift was significant in the control group (-0.42 ± 0.27 mm anterior shift; P = 0.009). The mean postoperative refractive shift 6 months after surgery compared with refraction on the first day after surgery was -0.16 ± 0.67 diopter (D) in the PCCC group and -0.60 ± 0.70 D in the control group (P = 0.042).

CONCLUSIONS

During cataract surgery, PCCC is useful to stabilize and minimize postoperative refractive changes. The IOL displacement attributable to capsular contraction is less when cataract surgery involves PCCC.

Effect of primary posterior continuous curvilinear capsulorhexis with and without posterior optic buttonholing on postoperative anterior chamber flare

PURPOSE

To evaluate the effect of primary posterior continuous curvilinear capsulorhexis (PCCC) with and without posterior optic buttonholing (POBH) on the anterior chamber reaction after small-incision cataract surgery.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

Consecutive patients with age-related cataract having cataract surgery in both eyes under topical anesthesia were prospectively enrolled in a randomized clinical trial. In randomized order, cataract surgery with combined primary PCCC and POBH was performed in 1 eye; in the other eye, cataract surgery was performed with primary PCCC and in-the-bag implantation of an intraocular lens. Intraocular flare was measured with an FC-1000 laser flare-cell meter preoperatively and postoperatively at 1, 4 to 6, and 24 hours, 1 week, and 1 month.

RESULTS

Thirty patients (60 eyes) were evaluated. The peak of intraocular flare was 1 hour postoperatively in all study eyes. In both groups, the response steadily decreased thereafter. Anterior chamber flare was statistically significantly higher in eyes with primary PCCC without POBH than in eyes with combined primary PCCC-POBH at all postoperative testing points (P<.001), including at 1 month (P = .01).

CONCLUSIONS

Cataract surgery with combined primary PCCC-POBH led to significantly lower postoperative anterior chamber reaction than conventional in-the-bag implantation during a 4-week follow-up. The tight capsule-optic diaphragm effectively prevented the ophthalmic viscosurgical device captured behind the optic from entering the anterior chamber postoperatively.

Macular morphology after cataract surgery with primary posterior capsulorhexis and posterior optic buttonholing

PURPOSE

To evaluate possible changes in macular morphology after cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing in comparison to conventional in-the-bag intraocular lens (IOL) implantation.

DESIGN

Prospective randomized study.

METHODS

Fifty consecutive age-related cataract patients with normal macular morphology and function waiting for bilateral cataract surgery were enrolled. Cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing was performed in one eye; in the fellow eye cataract surgery was performed with in-the-bag IOL implantation, leaving the posterior lens capsule untouched. Optical coherence tomography measurements were performed one week and one month postoperatively.

RESULTS

During follow-up, no statistically significant changes of macular morphology could be observed in any of the tested patients. Mean central retinal thickness, minimum and maximum retinal thickness, and central retinal volume were all statistically comparable between the eyes with combined primary posterior capsulorhexis and posterior optic buttonholing and the control eyes (P > .05). Best-corrected visual acuity was full in all patients (Snellen 20/25 and better). No cases of subclinical macular edema were observed.

CONCLUSION

Cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing apparently does not increase the risk for postoperative macular edema in patients with a normal macula, since no cases of biomicroscopically noticeable macular edema with visual loss were observed in the first 1,000 eyes with primary posterior capsulorhexis/posterior optic buttonholing cataract surgery and no case of subclinical macular edema was found in this prospective randomized study.

Posterior capsulorhexis combined with optic buttonholing: an alternative to standard in-the-bag implantation of sharp-edged intraocular lenses? A critical analysis of 1000 consecutive cases

Background

Current after-cataract prevention relies on optimizing the natural barrier effect of the optic rim against lens epithelial cell (LEC) migration. However, deficiencies in circumferential capsular bag closure caused by the intraocular lens (IOL) haptic or delayed secondary re-division of the fused capsules by Soemmering´s ring formation lead to primary or secondary barrier failure. Consequently, surprisingly high posterior laser capsulotomy rates have been reported long-term, even with optimal capsular surgery and the most widespread hydrophobic acrylic IOLs, considered to be the most advanced. Intraoperative removal of the central posterior capsule has been shown to be effective in further reducing LEC immigration. However, efficacy has turned out to be limited because of the propensity of LECs to use the posterior optic surface as an alternative scaffold.

Material and methods

Technique: in pediatric cataract surgery, buttoning-in of the optic into an adequately-centered posterior capsulorhexis opening has been described previously. This technique was further elaborated and applied as the standard technique in a large series of adult eyes. In general, the diameter aimed at was 5–6 mm for the anterior, and 4–5 mm for the posterior capsulorhexis. Between September 2004 and June 2007, 1000 consecutive cases have thus been performed and systematically evaluated. One hundred and fifty eyes additionally underwent extensive anterior LEC abrasion. Another sub-series investigated the option of further reducing capsular fibrosis by creating an anterior capsulorhexis larger than the optic.

Evaluation: special scrutiny was applied to detect postoperative vitreous entrapment. Regeneratory and fibrotic after-cataract formation were both meticulously followed-up. Postoperative pressure course, anterior segment inflammation, macular thickness and morphology, as well as axial optic stability and optic centration, were evaluated in intraindividual comparison studies.

Results

A low rate of vitreous complications was found, which can be avoided by appropriate surgery. Vitreous entanglement occurred in six eyes, and vitreous herniation after PPCCC over-sizing in two. In three, anterior vitrectomy was performed. There was only one single case of retinal detachment—supposedly unrelated to the technique itself—and no case of cystoid macular edema. Retro-optical regenerate formation was completely abolished, while fibrosis was drastically reduced by the posterior capsule sandwiched in between the anterior LEC layer on the backside of the anterior capsule and the anterior optic surface, thereby blocking contact-mediated myofibroblastic LEC transdifferentiation. Additional capsular polishing further reduced residual fibrosis emerging from the anterior capsule contacting the optic adjacent to the haptic junction, as well as regeneratory LEC re-proliferation on the posterior capsule overlying the optic. Postoperative pressure course was almost identical to that found after standard in-the-bag implantation of the IOL, as was flare, and macular thickness and morphology. As opposed to bag-fixated IOLs, no axial movement of the optic was detected. IOL optics always perfectly centered even when the capsular opening was not optimally centered. Due to the exquisite stretchability and elasticity of the posterior capsule, the 6-mm IOL optic could safely be buttoned-in in a posterior capsulorhexis of 4 mm and smaller.

Conclusions

Posterior optic buttonholing (POBH) is a safe and effective technique which not only excludes retro-optical opacification, but also withholds capsular fibrosis by obviating direct contact between the anterior capsular leaf and the optic surface. Anterior LEC abrasion significantly reduced both the residual fibrosis and regeneratory LEC proliferation. Apart from pediatric cataract, POBH is currently recommended for eyes with pseudoexfoliation syndrome, high axial myopia, peripheral retinal disease, and multifocal IOL implantation. Toric IOLs and magnet-driven accommodative IOL systems are other potential applications. Generally, POBH holds promise for becoming a routine alternative to standard in-the-bag IOL implantation in the future.