Astigmatic changes after cataract surgery with 5.1 mm and 3.5 mm sutureless incisions

Clinical Results of Cataract Surgery Using the ARTIS ® PL E Intraocular Lens

Purpose: To compare the clinical outcomes of cataract surgery using the ARTIS ® PL E (Cristalens Industrie, Lannion, France) intraocular lens (IOL) and conventional Tecnis ® ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA) IOL.Methods: This retrospective study examined patients who underwent in-the-bag implantation of either an ARTIS ® PL E (33 eyes, group A) or Tecnis ® ZCB00 (45 eyes, group B) IOL after phacoemulsification performed by a single surgeon. Best-corrected visual acuity (BCVA), spherical equivalent, and higher-order aberrations (HOA) were measured 1 and 3 months after cataract surgery.Results: Preoperative BCVA did not differ significantly in groups A and B. Postoperative BCVA at 1 and 3 months improved significantly (p < 0.001) in both groups compared to preoperative baseline BCVA. At 1 and 3 months postoperatively, total HOA, spherical aberration, and coma were significantly lower compared to the preoperative baseline HOA (p < 0.05) in both groups. However, there were no significant differences in the trefoil values 1 and 3 months postoperatively compared to the preoperative baseline in both groups. The absolute refractive error 3 months postoperatively was 0.27 ± 0.20 (group A) and 0.28 ± 0.20 (group B), both within ± 0.50 diopters of the targeted goal diopter; there were no significant differences in the accuracy or predictability of the IOL power calculation in both groups (p = 0.390, p = 0.959). The absolute refractive error 1 and 3 months postoperatively did not differ significantly; there were no significant differences in the stability of both IOLs (p = 0.482, p = 0.372).Conclusions: Conventional cataract surgery using the ARTIS ® PL E IOL significantly increased the BCVA, while obtaining comparable clinical results to the verified Tecnis ® ZCB00 IOL in postoperative visual acuity and HOA.

Prediction of refractive error in combined vitrectomy and cataract surgery with one-piece acrylic intraocular lens

Purpose

To compare the predicted and actual refractive errors of hydrophilic, one-piece, C-flex®570C (C-flex) intraocular lens (IOL) implantation in simultaneous vitrectomy and lens extraction in various conditions.

Methods

One hundred fifty-nine eyes of patients who had lens extraction between March 2004 and September 2005 were enrolled in a retrospective study. Group 1 had lens extraction and IOL implantation, and Group 2 had lens extraction and IOL implantation with vitrectomy. IOL calculation was done with axial length and keratometry measurements. The actual and predicted refractive errors were compared at 1 and 6 months postoperatively. The factors influencing the postoperative refractive outcomes were analyzed.

Results

The mean refractive predictive error (i.e., the actual minus predicted spherical equivalent) was +0.19±0.39 D (Diopter) and -0.26±0.45 D at 1 and 6 months postoperatively (all: p<0.001) in group 1, and -0.22±0.39 D and -0.06±0.62 D at 1 and 6 months postoperatively (p=0.013, p=0.399 respectively). In group 2, all surgical factors related to refractive errors were not statistically significant (all: p>0.05).

Conclusions

Refractive errors in combined surgery showed myopic shift of -0.50 D and -0.32 D at 1 and 6 months postoperatively compared with C-flex IOL implantation alone. With the hyperopic tendency of IOL and myopic tendency of vitrectomy, the combined surgery made postoperative refractive errors near emmetropia.

Optimal incision sites to obtain an astigmatism-free cornea after cataract surgery with a 3.2 mm sutureless incision

PURPOSE

To determine the optimal incision to eliminate astigmatism after cataract extraction.

SETTING

Hara Eye Hospital, Utsunomiya, Japan.

METHODS

Patients having cataract extraction through a 3.2 mm corneal limbal incision without limbal sutures were divided into 2 groups. Group 1 comprised 98 eyes of 80 patients without preoperative astigmatism and Group 2, 72 eyes of 62 patients with no astigmatism postoperatively. In Group 1, the incisions that caused postoperative corneal changes were retrospectively evaluated. In Group 2, the types of incisions that induced an astigmatism-free cornea postoperatively were retrospectively studied. Patients were examined preoperatively and 6 months postoperatively.

RESULTS

In Group 1, 23 of 40 eyes (57.5%) with an incision between 9 and 12 o'clock (BENT incision) and 10 of 58 eyes (17.2%) with an incision at 12 o'clock remained astigmatism free postoperatively (P <.0001). One eye (2.5%) with a BENT incision and 17 (29.3%) with a 12 o'clock incision had astigmatism greater than 1.0 diopter (D) postoperatively (P <.001). In Group 2, 72 eyes had less than 1.2 D of preoperative astigmatism. No eye with more than 1.2 D of astigmatism was astigmatism free postoperatively, even when the incision was made at the steepest meridian.

CONCLUSIONS

The results indicate that to reduce astigmatism in eyes with preoperative astigmatism of 0.5 D or more, a limbal 3.2 mm BENT incision should be placed at 10:30 o'clock. To prevent astigmatism postoperatively, the incision should be placed at the steepest meridian in eyes with preoperative astigmatism greater than 0.5 D; for preoperative astigmatism greater than 1.2 D, a 3.2 mm incision at the corneal limbus is insufficient and a wider incision or an additional incision is required.

Optic capture of the AcrySof intraocular lens in pediatric cataract surgery

PURPOSE

To assess the results of acrylic intraocular lens (IOL) optic capture in children with cataract.

SETTING

Department of Ophthalmology, Hospital de Clínicas José de San Martín, and Instituto de la Vision, School of Medicine, University of Buenos Aires, Argentina.

METHODS

Eight children had cataract surgery. After lens and cortex aspiration, an AcrySof (Alcon) IOL was implanted in the bag. A primary posterior capsulorhexis was performed. The optic edges were slipped through the posterior capsule leaflets. Clarity of the visual axis, preoperative and postoperative best corrected visual acuities (BCVAs), and refraction were evaluated.

RESULTS

The visual axis remained clear in all cases. No case required a secondary procedure. The mean preoperative BCVA was 0.06 +/- 0.06 (SD). Postoperatively, the mean BCVA was 0.88 +/- 0.11 and the mean spherical equivalent, +0.62 +/- 1.31. The mean follow-up was 28.9 +/- 5.3 months.

CONCLUSION

Results show that the optic of an acrylic IOL may be captured through a posterior capsulorhexis in pediatric cataract surgery, combining the advantages of optic capture with a smaller incision and a decreased inflammatory response.

Five year study of astigmatic stability after cataract surgery with intraocular lens implantation: comparison of wound sizes

PURPOSE

To assess the long-term stability of cataract wounds of various lengths.

SETTING

Private practice.

METHODS

This retrospective study comprised 5 groups of consecutive cataract surgery cases and 1 control group with similar mean ages and wound lengths of 10.0, 6.0, 4.0, 2.0, and 0 (control) mm. Except for the 4.0 mm cases, follow-up was 5 years, with few patients lost during that time. Cases within each group had the same wound position, configuration, and suturing. Refractive data, controlled by keratometry, were collected and analyzed preoperatively and 1 day, 1 and 6 weeks, 3 and 6 months, and 1, 2, 3, 4, and 5 years postoperatively. No sutures were cut.

RESULTS

With long-term follow-up, there was a progressive against-the-rule shift in astigmatism. Smaller wounds showed less immediate induced astigmatism. However, except for the unsutured 2.0 mm iridectomy wounds and the control group, all shifted similarly. Data were not available for the 4.0 mm wounds beyond 1 year.

CONCLUSION

Wounds were not necessarily "stable" at 6 months. Larger wounds continued to shift years after surgery. Smaller wounds have significant postoperative advantages, but absolute long-term refractive stability may not be one.

Phacoemulsification and modern cataract surgery

The techniques and results of cataract surgery have changed dramatically during the past three decades. In the USA, we have moved from intracapsular cataract extraction as the preferred technique to almost exclusively extracapsular techniques. Smaller incisions have become the standard, with phacoemulsification now being the method of choice for most surgeons. Along with these advances have come improved intraocular lens materials and designs, especially well suited for use with smaller incisions. Phacoemulsification as a method to remove the cataractous lens was first proposed more than 20 years ago. Advances in techniques and equipment have led to a dramatic increase in the popularity of phacoemulsification with increased safety and efficiency. Viscoelastic agents have been developed synchronously with modern phacoemulsification techniques, playing an integral role in the success of this new technology. Improved surgical techniques for removing the anterior lens capsule have decreased the incidence of both intraoperative and postoperative capsular complications. Nucleus removal, formerly performed primarily in the anterior chamber, is now performed in the posterior chamber, decreasing damage to the corneal endothelium. Improved wound construction allows many wounds to be left unsutured, and smaller wounds allow shorter recovery time and greater intraoperative control and safety. Intraocular lenses can have smaller optic sizes and still maintain accurate centration. Foldable intraocular lenses can take advantage of the smaller incision, even further shortening the time to visual recovery. Continual evolution of this technology promises to further improve patient outcomes after cataract surgery.

Surgically induced astigmatism with superior and temporal incisions in cases of with-the-rule preoperative astigmatism

PURPOSE

To evaluate surgically induced astigmatism (SIA), postoperative astigmatism, and uncorrected visual acuity (UCVA) after cataract surgery with superior corneal, superior scleral, and temporal corneal 4.0 mm sutureless incisions in cases of preoperative with-the-rule (WTR) astigmatism.

SETTING

Hopital des Quinze-Vingts, Paris, France.

METHODS

This prospective evaluation included patients having phacoemulsification with foldable lens implantation through a 4.0 mm incision. Patients with preoperative WTR astigmatism were randomly assigned to 1 of 3 incisions: superior corneal (Group 1), superior scleral (Group 2), or temporal corneal (Group 3). All patients had autokeratometry preoperatively and postoperatively (1 day, 1 week, 1 month, 1 year). Surgically induced astigmatism using the vector method, postoperative astigmatism, and UCVA (patients whose spherical equivalent was with +/- 1 diopter) were evaluated.

RESULTS

Ninety patients were included in the study; there were 30 in each incision group. One year postoperatively, Group 1 had 1.52 diopters (D) of SIA and 1.36 D of postoperative astigmatism; 53.5% of patients had a UCVA of 20/32 or better, Group 2 had 0.69 D of SIA (P < .05) and 0.67 D of postoperative astigmatism (P < .05); 82.7% of patients had a UCVA of 20/32 or better (P < .05). Group 3 had 0.69 D (P > .05), 0.98 D (P < .05), and 79.3% (P > .05), respectively.

CONCLUSIONS

In this study, the superior corneal incision produced significant SIA, leading to high postoperative astigmatism and poor UCVA. The scleral and temporal incisions produced minimal SIA and good UCVA.

Variation in astigmatism following the single-step, self-sealing clear corneal section for phacoemulsification

PURPOSE

A single-step, self-sealing, 3.2 mm clear corneal section is described and the incidence and variation of surgically induced astigmatism following phacoemulsification over a period of 3 months is determined.

METHODS

Twenty-two patients who underwent uncomplicated 3.2 mm clear corneal phacoemulsification with foldable Allergan silicone intraocular lens implantation were autorefracted pre-operatively and on day 1, week 1, week 6 and at 3 months. The variation in induced astigmatism was analysed using the subtraction method and vector analysis. The change in direction of the cylindrical axis was examined.

RESULTS

The induced astigmatism represented by the total vector on day 1 was 1.17 D and vector decomposition ratio, ATR:WTR (against-the-rule:with-the-rule), was 21.05:78.95. The total vector increased by 0.5 D in the first week and then stabilised. Vector decomposition showed an against-the-rule astigmatic drift so that by 3 months the ATR:WTR was 40.49:59.91. There was a tendency of the axis of the negative cylinder to swing towards the corneal section meridian on day 1 and to oscillate around that meridian at week 1 and week 6. By 3 months the direction reverted to that pre-operatively, in most cases.

CONCLUSIONS

The single-step, self-sealing clear corneal section is mechanically stable and, though there is some variability in the measured astigmatism, there is an acceptable functional result throughout the post-operative period.

Intraocular lens materials and styles: a review

Biomaterial science has lead to the development of a variety of foldable intraocular lens (IOL) biomaterials. This literature review examines these lenses from both a basic science and a clinical perspective. By most parameters, hydrogel, soft acrylic and silicone IOL are better than polymethylmethacrylate (PMMA) lenses. Plate haptic silicone IOL have the lowest incidence of cystoid macula oedema and posterior capsule opacification, but these lenses require an intact anterior capsularhexis and posterior capsule. Yttrium aluminium garnet (YAG) laser capsulotomy must be delayed at least 3 months to avoid posterior lens dislocation. Silicone has the lowest threshold for YAG laser damage of all IOL materials and also adheres irreversibly to silicone oil with subsequent optical impairment. Three piece silicone IOL with polypropylene haptics have a higher incidence of decentration, pigment adherence and capsule opacification compared with PMMA haptics. Hydrogel lenses are very biocompatible and resistant to YAG laser damage, but pigment adheres to the surface more readily than PMMA. Soft acrylic IOL unfold slowly, resulting in controlled insertion, but it is possible to crack the lens and some lenses develop glistenings due to water accumulation. There are significant socioeconomic implications to the large differences in posterior capsule opacification rates between the various biomaterials and the lens styles.

Induced astigmatism after near-clear hinge incision

PURPOSE

To evaluate astigmatism induced by the near-clear hinge incision.

SETTING

Casa di Cura Villa Toniolo, Bologna, and Day Hospital Nuova Ricerca, Rimini, Italy.

METHODS

The results in 100 eyes having phacoemulsification with a 3.2 or 4.1 mm temporal near-clear hinge incision were evaluated for a maximum of 6 months. Corneal curvature was measured using computerized videokeratography, and surgically induced astigmatism was computed by vector analysis. Surgically induced corneal topographic changes were also evaluated.

RESULTS

Mean induced cylinder in the 3.2 mm incision group was 0.4 diopter (D) +/- 0.2 (SD) 6 months after surgery; there was no significant difference in the values at 4 days and 6 months. Mean induced cylinder in the 4.1 mm incision group was similar at 1 and 6 months (0.47 and 0.45 D, respectively). However, it was significantly higher at 4 days (0.56 D). Vector decomposition analysis showed that the with-the-rule component was prevalent and remained constant over 6 months. Topographic analysis showed localized wound-related flattening with minimal central corneal changes.

CONCLUSION

The near-clear hinge incision was almost astigmatically neutral and resulted in self-sealing incisions that did not leak.

Corneal topographic changes after frown and straight sclerocorneal incisions

PURPOSE

To compare the corneal topographic changes following cataract surgery with two types of sclerocorneal tunnel incisions for implantation of 6.0 mm optic poly(methyl methacrylate) intraocular lenses.

SETTING

University Eye Hospital, Vienna, Austria.

METHODS

This prospective, unmasked, and unrandomized study comprised 48 otherwise healthy eyes scheduled for cataract surgery. A 4.5 mm sutureless frown incision was made in 22 eyes and a 6.0 mm straight sclerocorneal incision with a horizontal 10-0 nylon infinity suture in 26 eyes. Preoperatively and 1 week and 1 and 3 months postoperatively, corneal topography was recorded by the TMS-1 computer-assisted videokeratoscope (Computed Anatomy, Inc.). The data were evaluated by batch-by-batch analyses of the paired differences between the records. The significance of topographic changes was calculated by paired Wilcoxon tests; group comparisons were made using Wilcoxon tests.

RESULTS

In both groups, horizontal steepening and lower corneal flattening were consistently 0.4 diopter (D). Upper peripheral corneal flattening at 1 week and 1 and 3 months postoperatively was 0.7, 0.7, and 0.7 D, respectively, in the straight-incision group and 0.7, 0.4, and 0.3 D, respectively, in the frown-incision group. Vertical flattening and horizontal steepening were significant in both groups (P < .01). Group comparisons revealed significant differences in only 15 of 225 areas (P < .05).

CONCLUSION

There were no major differences between the two incision groups in surgically induced topographic changes.

Comparative study of intraocular lens implantation through 3.0 mm temporal clear corneal and superior scleral tunnel self-sealing incisions

PURPOSE

To compare the clinical outcome of phacoemulsification and foldable silicone intraocular lens (IOL) implantation through a 3.0 mm temporal clear corneal incision and 3.0 mm superior scleral tunnel incision.

SETTING

Department of Ophthalmology, Yodogawa Christian Hospital, Osaka, Japan.

METHODS

Eighty cataractous eyes of 78 patients with pre-existing against-the-rule (ATR) astigmatism were recruited for this prospective, randomized study. The patients were assigned to one of the two groups. Data on uncorrected and corrected visual acuities, keratometry, flare intensity measurement, and central cornea endothelial cell count were evaluated preoperatively and at 2 days, 1 week, and 1 and 3 months postoperatively.

RESULTS

Although the pre-existing keratometric cylinder decreased in the temporal clear corneal incision group and increased in the superior scleral tunnel incision group, the amount of cylinder shift was not significantly different. Mean scalar shift of keratometric cylinder in the corneal incision group was 1.19 diopters (D) at 2 days postoperatively, 0.86 D at 1 week, and 0.56 D at 3 months and in the scleral incision group, 1.09 D at 2 days, 0.76 D at 1 week, and 0.65 D at 3 months. Eighty percent of the eyes in each group achieved an uncorrected visual acuity of 20/40 or better from the second day postoperatively. No statistically significant difference in visual rehabilitation or other parameters was noted between the groups throughout the study. Complications including corneal endothelial cell loss and wound incompetence requiring suturing were observed in the temporal clear corneal incision group.

CONCLUSIONS

Both incisions offered satisfactory clinical results, but the superior scleral tunnel incision resulted in fewer complications. Minimal corneal keratometric change induced by a 3.0 mm incision was not related to uncorrected visual rehabilitation.

Corneal versus scleral tunnel incision in cataract surgery: a randomized study

PURPOSE

To compare the induced regular and irregular astigmatism after scleral and corneal tunnel incision.

SETTING

University hospital outpatient cataract clinic.

METHODS

One hundred phacoemulsification patients with less than 1.0 diopter (D) of preoperative astigmatism were randomly assigned to have a clear corneal incision (50 patients) or a scleral tunnel incision (50 patients). All incisions were 3.5 to 4.0 mm wide and were made in the steepest axis of the corneal astigmatism. The surgically induced astigmatism was analyzed by vector analysis from keratometric data, as well as by Fourier harmonic series analysis of the topographic data.

RESULTS

One day after surgery, the surgically induced astigmatism (vector analysis, keratometry) was 1.41 D +/- 0.66 (SD) and 0.55 +/- 0.31 D in the corneal incision group and the scleral incision group, respectively (P < .01). Six months after surgery, the induced astigmatism was 0.72 +/- 0.35 D and 0.36 +/- 0.21 D in the two groups, respectively (P < .01) The corneal topography data confirmed the regular astigmatism changes found by conventional keratometry. However, in addition, Fourier harmonic series analysis of the topography data showed significantly more irregular induced astigmatism with the corneal approach than with the scleral approach.

CONCLUSION

The clear corneal incision induces significantly more regular as well as irregular astigmatism than the scleral tunnel incision.

Clear corneal cataract surgery and the correction of myopia, hyperopia, and astigmatism

PURPOSE

Advances in cataract removal using topical anesthesia through a clear corneal microincision have created a new opportunity to fully correct refractive errors at the time of cataract surgery. This study was undertaken to assess the effectiveness of keratolenticuloplasty (KLP), the simultaneous modification of the cornea at cataract removal to create emmetropia with lens implantation.

METHODS

Data were analyzed for 690 consecutive cataract procedures performed between March 1993 and March 1995, with follow-up of 12 to 24 months. Each patient underwent cataract removal with topical anesthesia, clear corneal incision fashioned as an arcuate keratotomy to correct pre-existing astigmatism, intercapsular phacoemulsification, and microinjection of a single-piece elastic intraocular lens (IOL) into the capsular bag to correct spherical error.

RESULTS

Preoperative best-corrected visual acuity was worse than 20/50 in all patients; 58% were myopic, 32% were hyperopic, and 57% had astigmatism of greater than 1 diopter (D). Postoperatively, spectacle independence was achieved with uncorrected visual acuity of 20/40 or better in 87% of eyes. The sphere was fully corrected in 78%, within 1 D in 17%, and within 2 D in 5%. No patients were overcorrected. The cylinder was fully corrected in 72%, within 1 D in 26%, and within 2 D in 2%. Of those with residual astigmatism, there was no significant postoperative shift in cylinder axis. There were no sight-threatening complications. All patients were able to resume normal unrestricted activities within 24 hours of undergoing the procedure.

CONCLUSIONS

The KLP technique can correct spherical and astigmatic refractive errors, helping individuals become free of eyeglasses after clear corneal cataract surgery.

Correcting postoperative astigmatism using curved lamellating keratotomy

PURPOSE

To ascertain whether the change in refraction caused by paired lamellating corneal incisions in cadaver eyes could be achieved in living eyes and whether wound healing influences this effect.

SETTING

Virchow Hospital Eye Clinic, Humboldt University, Berlin, Germany.

METHODS

This prospective study included 45 patients who had a follow-up of 15 months. All had astigmatism of at least 2.00 diopters (D) induced by previous cataract surgery. Optical zones of 7.0 and 8.0 mm and chordal lengths of 3.0 and 5.0 mm were used. All incisions were paired.

RESULTS

Mean preoperative astigmatism measured with a keratometer was 3.64 D +/- 0.89 (SD). After 15 months, it was 1.00 +/- 0.76 D, and mean induced astigmatism was 3.18 +/- 1.30 D. The 7.0 mm group had a mean induced astigmatism of 3.93 +/- 1.52 D, which was significantly higher than that in the 8.0 mm group (mean 2.60 +/- 0.74 D) at a uniform chordal length of 3.0 mm. Mean uncorrected visual acuity was 0.26 +/- 0.14 preoperatively and 0.50 +/- 0.28 after 15 months; mean corrected visual acuity improved from 0.58 +/- 0.21 to 0.76 +/- 0.21. Mean endothelial cell count was 1799 +/- 595 cells/mm2 preoperatively and 1784 +/- 589 cells/mm2 after 6 months; the difference was not significant.

CONCLUSION

Curved lamellating keratotomy gives stable postoperative refractive results without significantly affecting endothelial cell count or visual acuity.

Astigmatism after phacoemulsification with adjusted and unadjusted sutured versus sutureless 5.2 mm superior scleral incisions

PURPOSE

To evaluate changes in astigmatism in the first 6 months after 5.2 mm superior scleral incision phacoemulsification using three different closures.

SETTING

Department of Ophthalmology, Vejle Hospital, Denmark.

METHODS

This study comprised 75 consecutive patients who had 5.2 mm superior scleral incision phacoemulsification. Patients were randomly assigned to one of three groups based on type of incision closure: Group 1, one intraoperatively adjusted cross suture; Group 2, one unadjusted cross suture; Group 3, no suture. Inclusion criteria were preoperative astigmatism of 2.00 diopters (D) or less (range of median 0.74 to 0.81 D) and no eye disease except cataract. Postoperative astigmatism was evaluated by keratometric cylinder, induced astigmatism (Naeser), and induced cylinder (Jaffe) on the first day and after 1 week and 1, 3, and 6 months. Time before stability was estimated.

RESULTS

All groups had the same level of postoperative keratometric cylinder with no significant change between 1 week and 6 months (range of median 0.81 to 1.06 D). The groups reached the same level of induced astigmatism (Naeser) 3 to 6 months after surgery (range of median -0.44 to -0.64 D). Group 3 (sutureless) reached that value after 1 week, and induced astigmatism was stable thereafter. Both sutured groups (Groups 1 and 2) had a highly significant change between the first week and third month (P < .01). There were no significant intergroup differences in induced cylinder (Jaffe), which stabilized after 1 week in Groups 1 and 2 and after 1 month in Group 3 (range of median 0.61 to 0.87 D). During the early postoperative period, variation was highest in Group 2.

CONCLUSIONS

Keratometric cylinder, induced astigmatism, and induced cylinder 3 to 6 months postoperatively were similar among the three groups, but early stability was only seen in the sutureless group. If a suture is used, intraoperative adjustment seems to result in lower variations in the early postoperative period.

Phacoemulsification versus endocapsular cataract extraction in a unique cohort of patients

The visual recovery and refractive results of 33 consecutive patients (66 eyes) undergoing standard endocapsular cataract extraction in one eye and simultaneous phacoemulsification in the fellow eye are reported. One surgeon performed all the operations. Surgically induced astigmatism was evaluated for the two techniques in terms of: (1) the proportion of eyes with a refractive cylinder of 1.5 dioptres (D) or less; (2) the interocular difference in post-operative astigmatism. Eyes undergoing phacoemulsification had a significantly lower mean induced cylinder (paired Student's t-test: t = 3.729; p < 0.001) and were more likely to exhibit a cylinder of 1.5 D or less (chi-squared test with Yates' correction: chi 2 = 7.88; p < 0.01) than the nuclear expression group. For paired eyes less post-operative astigmatism (Wilcoxon's signed rank test: T = 92; p < 0.01) was seen in the phacoemulsification eye. At the time of the last post-operative assessment a significantly higher proportion of phacoemulsified eyes achieved a corrected Snellen visual acuity of 6/6 or better than their fellow eyes (McNemar's test: p < 0.01). The results of this unique cohort of patients confirm the beneficial effects of phacoemulsification on astigmatism and visual outcome in the early post-operative period.

Evaluation of the first 50 ACR360 acrylic intraocular lens implantations

PURPOSE

To evaluate the clinical results of implantation of the ACR360 soft acrylic intraocular lens (IOL).

SETTING

Civico Hospital, Lugano, Switzerland.

METHODS

This prospective, medium-term study comprised the first 50 consecutive patients who had small incision scleral tunnel phacoemulsification and implantation of an ACR360 acrylic IOL (loptex/Allergan). Intraoperative and postoperative complications, best corrected visual acuity (BCVA), intraocular pressure (IOP), preoperative and postoperative astigmatism, and IOL centration were recorded. Mean follow-up was 12 months +/- 3 (SD).

RESULTS

One day postoperatively, 94% of best cases (n = 46) achieved a BCVA of 20/40 or better and 54%, 20/25 or better. At 2 weeks, 98% had 20/40 or better and 78%, 20/25 or better. After 6 months, all patients achieved a BCVA of 20/40 or better and 83%, 20/25 or better. No statistically significant changes in keratometric astigmatism or IOP occurred.

CONCLUSIONS

The ACR360 IOL gave clinical results comparable to those of other foldable lenses; however, it can also be implanted in cases of intraoperative capsular complications and in eyes with intravitreal silicone oil. Development of an injecting system for implantation and substituting the polypropylene loops with poly(methyl methacrylate) haptics could improve lens quality.

Corneal astigmatism after phacoemulsification and lens implantation through unsutured scleral and corneal tunnel incisions

PURPOSE

We compared the changes in corneal astigmatism after phacoemulsification and intraocular lens implantation in 93 consecutive eyes with unsutured 4-mm superior scleral tunnel incisions to those through 105 consecutive eyes with unsutured 3.2- to 3.5-mm temporal corneal tunnel incisions.

METHODS

Keratometry measurements were obtained preoperatively and at postoperative day 1, week 1, and week 6. Group differences in scalar and vector astigmatism were compared by using analysis of variance methods.

RESULTS

Mean scalar astigmatism in the scleral incision group changed from preoperative astigmatism by 0.65 diopter at postoperative day 1, 0.37 diopter at postoperative week 1, and 0.13 diopter at postoperative week 6. Mean scalar astigmatism in the corneal incision group changed from preoperative astigmatism by 0.39 diopter at postoperative astigmatism by 0.39 diopter at postoperative day 1, 0.21 diopter at postoperative week 1, and 0.13 diopter at postoperative week 6. Mean vector astigmatism in the scleral incision group changed 1.26 diopters at 80 degrees at postoperative day 1, 1.05 diopters at 83 degrees at postoperative week 1, and 0.42 diopter at 103 degrees at postoperative week 6. Mean vector astigmatism in the corneal incision group changed 0.77 diopter at 90 degrees at postoperative week 1, and 0.61 diopter at 89 degrees at postoperative week 6. The differences were statistically significant (P = .003) only by vector analysis at the postoperative day 1 examination.

CONCLUSIONS

We found significantly greater with-the-rule change in astigmatism in the scleral incision group than in the corneal incision group on the first postoperative day. The effect disappeared by the sixth postoperative week.

Bisecting a foldable acrylic intraocular lens for explantation

We describe a method of explanting an implanted foldable acrylic intraocular lens (IOL) through a small incision at the time of primary implantation without enlarging the original small incision. This method of bisecting foldable IOLs in the anterior chamber is safe and preserves the advantages of the original small incision.