[Reduction of astigmatism by 4mm long sutureless corneal cataract incision (stretch incision) with phacoemulsification and 5mm PMMA lens implantation]

AIM

Refractive cataract surgery using corneal incisions is aiming at neutralization of preoperative astigmatism.

PATIENTS AND METHODS

61 patients with preoperative astigmatism of 2.25 +/- 0.98 were included in the treatment. A self-sealing corneal tunnel incision measuring 4.0 to 4.1 mm in external diameter and 6.5 to 7.0 mm in internal diameter (stretch incision) was performed on the steeper axis. After capsulorhexis and phacoemulsification a 5 mm PMMA lens was implanted without suturing. Keratometry and corneal topography were performed preoperatively, 3 days and 1 year respectively following surgery. The statistical analysis was based on the Wilcoxon signed ranks test.

RESULTS

Surgical induced astigmatism (IA) following superior incisions in cases of astigmatism with the rule (n = 29) amounted to 1.93 +/- 0.97, while lateral incisions in cases of astigmatism against the rule (n = 29) led to an IA of 1.35 +/- 0.73. Axial shifts by more than 30 degrees were 23% following superior incisions and 17%, after lateral incisions. We observed. astigmatic reduction of 1.3 D after superior incisions and 0.7 D following lateral incisions.

CONCLUSION

By 4 mm corneal cataract incisions on the steeper axis a high preoperative astigmatism can be reduced significantly without additional keratotomies.

The effect of mitomycin-C on postoperative corneal astigmatism in trabeculectomy and a triple procedure

BACKGROUND AND OBJECTIVE

The authors attempted to determine the effect of mitomycin-C (MMC) on postoperative corneal astigmatism in patients who underwent trabeculectomy or a triple procedure (trabeculectomy, extracapsular cataract extraction, and intraocular lens implantation).

PATIENTS AND METHODS

Using the vector analysis method, the authors measured the postoperative induced astigmatism of 76 eyes in 59 patients who underwent trabeculectomy or a triple procedure with or without the application of MMC. Postoperative induced astigmatism corresponding to the 180 degrees axis was compared between the two groups.

RESULTS

The patients who underwent trabeculectomy with or without MMC showed a mean induced astigmatism of -1.01 D and -2.63 D, respectively, after 1 month (P < .05), and 0.34 D and -1.42 D after 12 months (P < .05). Those who underwent a triple procedure with or without MMC showed a mean induced astigmatism of -1.81 D and -4.50 D, respectively, after 7 days (P < .05), and 1.73 D and -0.13 D, respectively, after 12 months (P < .05). The entire amount of postoperative against-the-rule astigmatic shift was similar between the with-MMC group and the without-MMC group. The against-the-rule astigmatic shift of the group without MMC reached a plateau after 3 months. However, the group with MMC showed continuous against-the-rule astigmatic shift until 12 months.

CONCLUSION

This study suggests that MMC induces less with-the-rule astigmatism in early postoperative periods and continuous against-the-rule shift after 3 months following a trabeculectomy or a triple procedure.

Prospective randomized comparison of phacoemulsification cataract surgery with a 3.2-mm vs a 5.5-mm sutureless incision

PURPOSE

To report sutureless cataract surgery by phacoemulsification with a 3.2-mm surgical incision compared with a 5.5-mm surgical incision.

METHOD

In a prospective, randomized, masked clinical trial of phacoemulsification cataract surgery, 55 eyes (55 patients) had a 3.2-mm incision and 56 eyes (56 patients) had a 5.5-mm incision. All incisions were in the superior vertical meridian, commenced 1.5 mm posterior to the limbus, and extended into the cornea for a total length of 2.5 to 3.0 mm. In a masked fashion, astigmatism was monitored by keratometry, and logMAR visual acuity was determined both with and without best correction throughout a mean follow-up of 33.9 months.

RESULTS

Statistically significant differences were seen in favor of the 3.2-mm incision group at the final examination for astigmatism (Cravy analysis) and uncorrected visual acuity (-0.18 vs -0.88 diopter, P < .001; logMAR, 0.14 vs 0.26, P = .04).

CONCLUSIONS

Over the long term, phacoemulsification with a 3.2-mm incision is associated with significantly less astigmatic shift and better uncorrected visual acuity than is phacoemulsification with a 5.5-mm incision. A small incision with a foldable intraocular lens has long-term benefits.

Effect of superior and temporal clear corneal incisions on astigmatism after sutureless phacoemulsification

PURPOSE

To evaluate the effect of superior and temporal clear corneal incisions on astigmatism after sutureless, small incision phacoemulsification.

SETTING

World Eye Hospital, Istanbul, Turkey.

METHODS

This prospective study evaluated 40 eyes of 20 patients with cataract having bilateral, sutureless, small incision phacoemulsification by the same surgeon. A superior clear corneal incision was used in all right eyes and a temporal clear corneal incision in all left eyes. Mean preoperative astigmatism was 0.63 diopter (D) +/- 0.21 (SD) and 0.65 +/- 0.20 D, respectively. Mean patient age was 66.45 years. Patients were examined preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively.

RESULTS

Three months postoperatively, mean astigmatism was 1.60 +/- 0.37 D in the superior incision group and 0.83 +/- 0.19 D in the temporal incision group. Induced astigmatism calculated by vector analysis was 1.44 +/- 0.31 D and 0.62 +/- 0.28 D, respectively. The temporal incision group had significantly lower astigmatism at all follow-ups (P = .000).

CONCLUSION

Upper lid pressure on the superior corneal incisions led to fluctuating, against-the-rule astigmatism that was significantly higher than that induced by temporal incisions.

Graft decentration in penetrating keratoplasty: nonmechanical trephination with the excimer laser (193 nm) versus the motor trephine

BACKGROUND AND OBJECTIVE

Graft decentration is an obvious cause of postkeratoplasty astigmatism. The purpose of this study was to compare graft decentration after nonmechanical trephination with the excimer laser (193 nm) with that after mechanical motor-trephination in 50 consecutive patients with Fuchs' dystrophy and 50 patients with keratoconus.

PATIENTS AND METHODS

To determine decentration in absolute values and clock hours, a postoperative slide was projected with a fixed magnification onto a pattern with circles corresponding to the trephination margin. Using a second transparent and movable pattern with concentric circles and ellipses, the authors measured the amount and direction of decentration relative to the limbus and to the pupil. In addition, the keratometric astigmatism and the refractive cylinder were assessed. In this prospective study, the patients were assigned randomly to either method of trephination.

RESULTS

The decentration was significantly lower (P < .002) with excimer laser trephination (0.23 +/- 0.26 mm, relative to the limbus; 0.33 +/- 0.26 mm, relative to the pupil) than with mechanical trephination (0.58 +/- 0.23 mm, relative to the limbus [P < .01]; 0.64 +/- 0.24 mm, relative to the pupil [P < .005]). There was no significant difference between the results obtained in patients with Fuchs' dystrophy and those of patients with keratoconus. The preferred direction of decentration relative to the pupil was the lower quadrants. There was a mild correlation between net astigmatism and the absolute value of decentration. However, with sutures in place, there were no significant differences in the keratometric net astigmatism between mechanical and nonmechanical trephination (P = .16) or between Fuchs' dystrophy and keratoconus (P = .18).

CONCLUSIONS

The results indicate that the amount of decentration can be reduced by specific techniques associated with nonmechanical trephination. This might have a favorable impact on the residual astigmatism after suture removal.

Nucleus fragmentation in a scleral pocket for small incision extracapsular cataract extraction

We present a technique for planned manual extracapsular cataract extraction (ECCE) incorporating a modification of mini-nuc ECCE in which the scleral tunnel is made wide enough to allow a nucleus of any size to settle in the tunnel. A 5.0 mm, inverted-V chevron incision is used in which the exposed part of the nucleus lodged in the scleral pocket can be manually picked and fragmented until it is small enough to be removed through the incision. The chevron incision is flexible enough to allow a medium-sized nucleus to be extracted without fragmentation and implantation of a rigid 6.0 mm poly(methyl methacrylate) lens. Vector analysis of preoperative and 3 month postoperative keratometric results in 30 patients showed that the surgically induced vector was 0.54 diopter (D) +/- 0.58 (SD). Mean reduction in astigmatism was 0.08 +/- 0.39 D. The sutureless technique is fast and safe, allows a nucleus of any size to be extracted through a constant size 5.0 mm incision, and results in minimal postoperative astigmatism.

Refractive aspects of cataract surgery

The refractive aspects of cataract or lens surgery has formed a new field of operations. To reduce astigmatism and high myopia, surgeons are looking into alternatives and using various incision techniques as well as phakic intraocular lenses or clear lens extraction to achieve emmetropia. High hyperopia with short axial length and high required intraocular lens power are corrected by piggyback intraocular lens implantation. The use of multifocal intraocular lenses compensates for the loss of accommodation after lens extraction.

[Effects of surgical wounds hermetic closure methods in cataract extraction on postoperative corneal astigmatism]

Main factors of hermetic closure of the operation wound after cataract extraction are discussed. A new method of closing the wound in this operation is described. The opposition intracorneal mattress sutures are made across the section plane. Their principal difference is that the thread is not thrown over the external edge of the section of the cornea, as in traditional suturing, and when pulled tight, the thread does not deform the external surface of the cornea in the central zone, and thus does not induce postoperative astigmatism. Eighteen patients were operated on using this technique. Opposition sutures made after the above technique involve no high postoperative astigmatism or none at all.

Analysis of videokeratography after penetrating keratoplasty: topographic characteristics and effects of removing running sutures

OBJECTIVE

Previous studies have shown that removal of running sutures after penetrating keratoplasty causes unpredictable changes in astigmatism. The current study was conducted to investigate whether computer-assisted videokeratography is beneficial for predicting visual outcomes after running sutures are removed.

DESIGN

The design was that of a prospective clinical study.

PARTICIPANTS

The authors prospectively studied 29 consecutive eyes undergoing a 10-0 nylon running suture removal after penetrating keratoplasty.

INTERVENTIONS

Videokeratography was performed before, 1 week, 1 month, and 3 months after removal of sutures.

MAIN OUTCOME MEASURES

Changes in refractive and topographic astigmatism after suture removal were measured. Topographic patterns and their quantitative descriptors also were analyzed.

RESULTS

An asymmetric bowtie was the most common videokeratography pattern both before and after suture removal. After suture removal, the incidence of peripheral corneal steepening increased significantly (2 vs. 21 eyes, P < 0.0001), and that of focal flattening of the midperipheral cornea decreased (13 vs. 5 eyes, P = 0.046). The mean topographic astigmatism, surface regularity index, and corrected visual acuity were improved significantly by suture removal in eyes that had localized flattening but not in eyes without this finding. Eyes having either skewed axis in astigmatism or topographic astigmatism of more than 9 diopters also showed significant decreases in astigmatism.

CONCLUSIONS

Suture removal after keratoplasty is advantageous for both reducing astigmatism and normalizing topography, especially in eyes that have localized flattening of the midperipheral cornea. Predictability of visual outcomes of a running suture removal in postkeratoplasty eyes may be improved by the use of videokeratography.

New caliper for small incision cataract surgery

In cataract surgery, incision size determines various factors such as wound stability, corneal curvature changes, postoperative induced astigmatism, and visual rehabilitation. A mechanical caliper has been developed for experimental and clinical studies of incision sizes ranging between 1.0 and 6.0 mm. The caliper has a screw that allows measurements in 0.1 mm steps. The device is produced for two ranges: 2.0 to 4.0 mm and 1.0 to 6.0 mm. The precision of 0.1 mm was confirmed with a vernier caliper in a cadaver eye study. Unlike gauges that determine incision size by trial and error and a combined system of internal and vernier calipers, only one measurement is necessary with this caliper.

Computerized topography of selective versus all-suture release to manage high astigmatism after cataract surgery

PURPOSE

To compare the efficacy of selective suture release (SSR) with all-suture release (ASR) in controlling corneal astigmatism after cataract surgery.

SETTING

Sight Saver's Cornea Training Centre, L.V. Prasad Eye Institute, Hyderabad, India.

METHODS

This prospective, randomized study evaluated the effect on astigmatism of two techniques of suture release in 30 patients with more than 3.00 diopters (D) of corneal astigmatism after cataract surgery. All patients had interrupted sutures with well-healed wounds. Fifteen patients had ASR irrespective of the location of the steep meridian. In the other 15, only the suture located in the steep meridian was selectively released. The pattern of decay of astigmatism after suture release was studied using computerized videokeratography.

RESULTS

Mean pretreatment corneal cylinder was 6.30 D +/- 2.72 (SD) in the ASR group and 6.95 +/- 1.67 D in the SSR group. In the ASR group, corneal cylinder dropped to 3.70 +/- 1.15 D immediately after suture release and further decreased to 1.82 +/- 0.66 D at 1 week (P < .001). In the SSR group, astigmatism swung erratically to the adjoining sutures and decreased unpredictably at an average of 1.32 +/- 2.00 D with each suture release.

CONCLUSION

The ASR technique was more predictable and less cumbersome than the SSR method.

[Asymmetric corneal tunnel incision for routine phacoemulsification and lens implantation]

This study was designed to investigate whether it is possible to improve wound stability and reduce induced astigmatism of a linear corneal tunnel incision for the implantation of foldable intraocular lenses by radializing wound components.

MATERIALS AND METHODS

A 4.1-mm linear and a 2.5 x 2.5-mm L-shaped corneal tunnel incision were compared in 60 and 59 patients, respectively.

RESULTS

Complications and induced astigmatism (vector analysis) were significantly less in the L-shaped incision group than in the linear incision group (0.62 +/- 0.53 D vs. 0.84 +/- 0.75 D after 3 months).

CONCLUSION

An L-shaped incision seems to be superior to the conventional linear type.

Effect of incision location on preoperative oblique astigmatism after scleral tunnel incision

PURPOSE

To evaluate the effect of incision location or clinically relevant preoperative oblique astigmatism.

SETTING

Department of Ophthalmology, Virchow Medical Center, Humboldt-University, Berlin, Germany.

METHODS

This prospective study included 68 patients who had phacoemulsification and posterior chamber lens implantation using a standardized 7.0 mm self-sealing trapezoidal scleral tunnel incision. Each patient was randomly assigned to one of three incision locations: Group A, conventional superior incision; Group B, temporal incision; Group C, oblique incision centered on the steeper meridian (modified BENT incision). Astigmatism analysis was performed by manual keratometry and corneal topography.

RESULTS

A significant mean reduction in astigmatism of 0.58 diopter (D) (P < .01) was achieved in only the modified BENT incision group. Postoperatively, significant flattening of 0.27 D (P < .01) in the steeper meridian as well as steepening of 0.29 D (P < .01) in the flatter meridian occurred. No decrease in astigmatism was noted in the superior or temporal incision groups. Five months postoperatively, vector analysis showed that surgically induced astigmatism was significantly higher in the superior incision group (1.16 D +/- 0.44 [SD]) than in the temporal incision group (0.66 +/- 0.32 D) or modified BENT incision group (0.82 +/- 0.50 D). Corneal topographic analysis confirmed these results within +/- 0.3 D.

CONCLUSIONS

Only the oblique incision centered on the steeper meridian (modified BENT incision) effectively and predictably reduced preoperative oblique astigmatism. In eyes with clinically relevant oblique astigmatism, we recommend using a modified BENT incision.

Corneal topography after selective suture removal for astigmatism following keratoplasty

BACKGROUND AND OBJECTIVE

The authors sought to determine whether the immediate corneal topographic changes induced by selective suture removal for astigmatism after keratoplasty were stable over time.

PATIENTS AND METHODS

Computerized videokeratoscopic images were obtained prior to and immediately following suture removal in 14 patients, and then again at the next postoperative visit 4 to 6 weeks later. These images were analyzed and statistically compared for central corneal power and vector of the central 3-mm corneal astigmatism.

RESULTS

Most of the topographic changes induced by suture removal occurred immediately. However, continued shifting in corneal curvature did take place over the subsequent 4 to 6 weeks. Unpredictable shifts were more pronounced in patients whose surgery had been performed more than 20 months prior to suture removal.

CONCLUSION

Computerized videokeratoscopy graphically elucidates continued shifts in corneal topography following the removal of sutures for the control of astigmatism after keratoplasty.

[7 mm tunnel incision with lateral approach as routine intervention in cataract surgery]

As the lateral incision in comparison to the classic incision at the 12 o'clock position induces less astigmatism and shows higher wound stability, we wanted to determine if this technique could be used as a routine procedure for most patients.

PATIENTS AND METHODS

A total of 186 patients were prospectively included in this study. They all had a lateral incision with the no-stitch technique, either as a clear corneal incision or as a corneoscleral or scleral incision. Postoperatively, patients were followed up for up to 12 months.

RESULTS

Whereas the scleral incision showed the highest wound strength, one patient with a corneoscleral incision needed a later suture. There were two cases of endophthalmitis after a clear corneal incision; 6-12 months postoperatively the mean induced astigmatism amounted 0.64 +/- 0.22 D after a scleral incision, 0.71 +/- 0.47 D after a corneoscleral incision, and 0.92 +/- 0.63 D after a clear corneal incision.

CONCLUSION

The lateral approach with a scleral is a safe procedure and induces very little astigmatism. It can be used routinely for all patients who have inverse preoperative astigmatism or none at all. The clear corneal incision shows instable wound closure and a higher infection risk. In the long term it induces an astigmatism of about 1 D and therefore is of no use for correction of higher inverse astigmatism.

[3 1/2 years experiences with ECCE with tunnel incision]

Since January 1992 planned extracapsular cataract extraction (ECCE) is performed routinely with the no-stitch technique at our clinic. To minimize surgically induced astigmatism further, modified wound constructions for planned ECCE with on 1.1-mm tunnel width were evaluated. The follow-up time was up to 3 years postoperatively. For 250 eyes wound closure was performed prospectively either sutureless (n = 70), with a single perpendicular suture (n = 100) or cross sutures (n = 40) at the 12 o'clock position or sutureless in the temporal position (n = 40). The complication rate was 4% (filtering bleb, iris prolapse or transient hypotonia). There were no wound ruptures, but once endophthalmitis was observed. Late mean astigmatism after up to 3 years follow-up for vertical incision was 2.05 +/- 1.16 D (1.01 +/- 0.96 D preoperatively) for sutureless wound closure, 1.63 +/- 1.08 D (0.86 +/- 0.95 D) for perpendicular and 1.76 +/- 0.88 D (0.73 +/- 0.55 D) for cross-sutures. A temporal incision resulted in 0.78 +/- 0.52 D (1.0 +/- 0.69 D) of astigmatism and was only performed on eyes with against the rule astigmatism preoperatively. Surgically induced astigmatism was stabilized early. For with the rule astigmatism preoperatively, a 12 o'clock incision with a perpendicular single suture is recommended and for against the rule astigmatism, a temporal incision.

[Factors modifying postoperative astigmatism after no-stitch cataract surgery]

BACKGROUND

One of the main advantages of the no-stitch technique in cataract surgery is that induced astigmatism occurs less frequently than with any other procedure and stabilizes within a very short time postoperatively. The resultant high wound strength enabled us to alter the incision parameters in an attempt to identify those which influenced postoperative astigmatism, the ultimate goal being to improve the prognosis of the expected astigmatism. Since the influence of tunnel width and incision length and shape were well known, we investigated the influence of incision depth and site and that of various parameters in a prospective randomized and controlled clinical trial.

METHODS

The study included 256 eyes with a 7-mm tunnel incision as examined in 256 patients. The following subgroups of 27 eyes each were investigated: primary incision depth of 300 microns versus 500 microns, limbal incision versus scleral incision, scleral incision in the 12 o'clock position versus temporal scleral incision, and limbal incision in the 12 o'clock position versus temporal limbal incision. In another group the influence of age, IOP, axial length of the globe, preoperative astigmatism, corneal diameter, and postoperative astigmatism as measured by the keratometer were all assessed using Spearman's correlation coefficient.

RESULTS

Temporal incisions made 2 mm posterior to the limbus resulted in induced astigmatism of 0.64 +/- 0.22 D 6 months postoperatively, which was less than after incisions in the 12 o'clock position (0.98 +/- 0.40 D). Induced astigmatism was highest after limbal incisions in the 12 o'clock position (1.31 +/- 0.60 D), yet was less if a temporal limbal incision was made (0.84 +/- 0.52 D). Incision depth did not have significant influence on induced astigmatism. Of the parameters, age (Spearman's correlation coefficient after 4 weeks 0.34; P = 0.002; after 6 months 0.28; P = 0.01), and preoperative astigmatism (Spearman's correlation coefficient after 4 weeks 0.28; P = 0.01; after 6 months 0.27; P = 0.01) had a significant influence on postoperative astigmatism.

CONCLUSIONS

These findings indicate that induced astigmatism was highest after limbal incisions in the 12 o'clock position and lowest after scleral incisions in the temporal position. Age and preoperative astigmatism were also found to influence induced astigmatism significantly. All of these factors have to taken into account to minimize postoperative astigmatism.

A comparison of two selective interrupted suture removal techniques for control of post keratoplasty astigmatism

PURPOSE

Two selective interrupted suture removal techniques were compared to determine which technique resulted in earliest, best visual acuity and least postoperative astigmatism.

METHODS

Sixty-five consecutive optical penetrating keratoplasties were performed using 12 interrupted 10-0 nylon sutures and a 12-bite continuous 10-0 nylon suture, and were alternately assigned to 1 of 2 selective suture removal groups. All patients had refraction, keratometry, and videokeratoscopy postoperatively, starting at 6 weeks. Six weeks postoperatively, Group I underwent simultaneous removal of six alternate sutures, with the first of the 6 sutures removed at the steepest meridian, while Group II had selective sutures removed only at the steepest meridian, if associated with greater than 2 diopters of astigmatism in that meridian. Subsequently, interrupted sutures were then selectively removed until the resultant astigmatism approached 3.0 diopters or less. Measurements of resultant astigmatism are reported prior to selective suture removal, following selective suture removal, at 6 months postoperatively, at the completion of all selective suture removal, and at the final visit.

RESULTS

At 6 months, residual astigmatism after the 2 techniques of selective suture removal, as measured by refraction, keratometry, and computer-assisted videokeratoscopy, was 2.8, 3.0 and 3.4 diopters for Group I, and 2.2, 2.6 and 3.7 diopters for Group II. At 1 year, the average final visit, astigmatism was 2.5, 2.4 and 2.7 diopters for Group I, and 2.1, 2.0 and 2.3 diopters for Group II. By the final visit, a best corrected vision of 20/50 or better was achieved in 86% of eyes in Group I and in 65% of eyes in Group II, and there was a significant difference in average keratometry of 47.4 diopters in Group I compared to 46.0 diopters in Group II and, as measured by videokeratoscopy, 47.9 diopters in Group I compared to 45.8 diopters in Group II.

CONCLUSIONS

Selective suture removal by either technique reduces keratoplasty astigmatism with residual interrupted and continuous sutures in place. The combined use of refraction, keratometry, and videokeratoscopy probably provides more reliable and reproducible quantitative measurements of astigmatism. Minimizing astigmatism by selective suture removal is a major factor in the attempt to achieve excellent and visual function in the majority of patients who have undergone penetrating keratoplasty.

Combined cataract and glaucoma procedures using temporal cataract surgery

PURPOSE

To evaluate whether separating the procedures in a combined procedure by performing a temporal cataract incision and superior trabeculectomy induces the lower astigmatism of a temporal cataract incision without sacrificing intraocular pressure (IOP) control.

SETTING

EyeSight Associates, Warner Robins, Georgia.

METHODS

This study evaluated 50 consecutive eyes receiving a superior cataract incision with a superonasal trabeculectomy and 65 eyes receiving a temporal cataract incision with a superonasal trabeculectomy.

RESULTS

After 3 months, a substantially greater proportion of temporal incision cases had controlled IOP without medication. A substantially higher proportion in the superior incision group had uncontrolled IOP at each time period. Mean surgically induced cylinder was higher in the superior incision group at every time period. The superior group had early with-the-rule mean induced cylinder that decayed to against-the-rule, with a mean induced cylinder with keratometry at the final available visit (more than 3 months) of -1.01 diopter (D). The temporal group started with a negligible induced cylinder (-0.13 D) that drifted slightly with the rule to a final mean induced cylinder of +0.49 D. At the last visit, 31% in the superior incision group and 57% in the temporal incision group had an uncorrected visual acuity of 20/40 or better, and 72% and 94%, respectively, had a best corrected acuity of 20/40 or better.

CONCLUSION

Separating the cataract and glaucoma procedures frees the surgeon to use newer astigmatically neutral techniques for the cataract incision.

The J-incision for phacoemulsification

The J-incision phacoemulsification technique combines a small, short (no-stitch) frown incision tunnel with a wider, longer extension tunnel pocket for easier intraocular lens implantation. The technique was used in 26 cases. Mean induced astigmatism calculated by Jaffe vector analysis was 0.77 +/- 0.62 D on day 1 and 0.61 +/- 0.56 D at 3 months. Using Naeser's method (polar value), it was -0.10 +/- 0.84 D and -0.25 +/- 0.62 D, respectively. No wound leakage or hyphema occurred.

Comparison of suture-in and suture-out postkeratoplasty astigmatism with single running suture or combined running and interrupted sutures

PURPOSE

To evaluate postkeratoplasty astigmatism between two suture techniques 2 to 4 years postoperatively in a group of patients previously studied 9 months postoperatively.

METHODS

Thirty-two patients who underwent penetrating keratoplasty were randomly assigned to one of two groups. Group 1 (16 patients) had a 24-bite single running 10-0 nylon suture with postoperative suture tension adjustment; group 2 (16 patients) had combined 16-bite running and eight interrupted 10-0 nylon sutures with selective postoperative removal of interrupted sutures. During long-term follow-up, the running suture was removed in 19 patients (59%).

RESULTS

Postoperative astigmatism was slightly lower in patients with the single running suture technique when sutures were in place and was slightly greater after the sutures were removed compared with the combined running and interrupted suture technique (sutures in: single running suture +/- SD, 2.6 +/- 1.2 diopters [five patients, 31%]; combined running and interrupted sutures, 3.8 +/- 1.1 diopters [eight patients, 50%]; sutures out: single running suture, 3.3 +/- 1.3 diopters [11 patients, 69%]; combined running and interrupted sutures, 2.8 +/- 1.5 diopters [eight patients, 50%]). These differences were not statistically significant (sutures in, P < .13; sutures out, P < .46). Averages of follow-up were group 1,48.3 +/- 10.6 months and group 2, 46.3 +/- 13.0 months. Follow-up ranged from 23 to 60 months.

CONCLUSIONS

Postoperative astigmatism 4 years after penetrating keratoplasty is similar for these two suturing techniques, with or without residual sutures. A single running suture results in more rapid visual rehabilitation and less early astigmatism compared with the combined interrupted and running suture technique.

Astigmatism reduction: no-stitch 4.0 mm versus sutured 12.0 mm clear corneal incisions

PURPOSE

To compare the effect on astigmatism of phacoemulsification using a 4.0 mm, no-stitch, clear corneal incision with that of extracapsular cataract extraction (ECCE) using a 12.0 mm, sutured, clear corneal incision.

SETTING

Augenklinik, Städtisches Klinikum Karlsruhe, Germany.

METHODS

The study comprised 211 patients who had cataract extraction and intraocular lens implantation through a superior clear corneal incision; 108 patients had phacoemulsification with a 4.0 mm no-stitch incision, and 103 had ECCE using a 12.0 mm sutured corneal incision. The main outcome measure was amount of astigmatism preoperatively and at 1 week and 3 and 6 months postoperatively. Corresponding medians (lower and upper quartiles) were evaluated.

RESULTS

Median surgically induced cylinder was 1.00 diopter (D) (range 0.56 to 1.50 D) in the 4.0 mm no-stitch incision group and 1.75 D (range 1.00 to 2.62 D) in the 12.0 mm sutured incision group. In eyes with preoperative with-the-rule astigmatism, astigmatism decreased from a median of 0.75 D (range 0.50 to 1.00 D) to 0.50 D (range 0 to 1.50 D) in the 4.0 mm incision group. The difference between preoperative and postoperative astigmatism in the 12.0 mm incision group was not statistically significant.

CONCLUSION

Clear corneal cataract surgery leads to a predictable reduction in astigmatism when performed on the steeper axis with a small, no-stitch incision. Larger sutured incisions are not suitable for planned refractive changes but are still recommended in certain cases such as hard cataract and glaucoma.