Temporal Clear Corneal Incision Research Articles

SURGICAL MANAGEMENT OF COEXISTING GLAUCOMA AND CATARACT

As longevity increases among the elderly, the challenge of managing coexisting glaucoma and cataract is becoming ever more frequent. Modern surgical techniques for cataract removal (e.g., small incision phacoemulsification and temporal clear corneal incision) spare conjunctiva and minimize disruption of the anterior chamber angle. Postoperative bleb titration with releasable scleral flap sutures and antifibrotic medications increases the chance for successful aqueous filtration. These advances have made us reconsider the choice for performing cataract extraction and trabeculectomy together or in sequential steps (staged surgery) for eyes with coexisting cataract and glaucoma. There are many issues (Table 1) to consider in the surgical treatment of coexisting glaucoma and cataract including medication compliance, side effects, and cost. The severity of glaucomatous visual field loss and optic nerve damage and the level of intraocular pressure (IOP) influence the surgical decision. The possibility of further optic nerve damage from a postoperative IOP spike must be addressed. The type of glaucoma and the preoperative state of the conjunctiva and anterior segment also influence the decision-making process. Cataract extraction presents extra hazards in the glaucomatous eye relating to poor pupillary dilation caused by miotic use and diminished zonular integrity in eyes with exfoliation syndrome. The surgical approach for cataract extraction is also important. Large incision extracapsular cataract extraction (ECCE) or scleral tunnel phacoemulsification cause limbal and conjunctival scarring that may have an impact on the success of future glaucoma surgery. This can be avoided by using a clear corneal incision for removal of the cataract. In previous years, combined cataract and filtration surgery has gained favor over procedures. Combined surgery is convenient for the patient because two procedures are done during a single operation. It also diminishes the likelihood of a postoperative IOP spike, which is common when cataract surgery is performed alone. 18 This trend has resulted in more eyes with glaucoma who are destined for cataract extraction having a trabeculectomy added secondarily. Nevertheless, combined surgery risks more intraoperative and postoperative complications than either operation separately, slower visual recovery than cataract surgery alone, and lower chance of developing a filtration bleb. In this article we review the available information on the surgical management of eyes with coexisting cataract and glaucoma and present a rationale for a return to sequential or staged surgery. We approach each patient with glaucoma and cataract by considering the status of the patient's glaucoma and the patient's need for improved vision. Whatever procedures are selected, the ultimate goals should be an adequate IOP and improved quality of life by improving vision and decreasing the need for antiglaucoma medications.

Corneal Refractive Changes after Acrysof Lens versus PMMA Lens Implantation

Purpose: Do foldable acrylic lenses yield not only reduced posterior capsular opacification but also significant refractive advantages? Patients and Methods: 147 cataract patients including 47 with spherical corneas and 100 with preoperative astigmatism of 0.8 ± 0.7 dpt were treated in one of two ways: 70 patients received 5.5-mm Acrysof lens implants through 3.2-mm outer and 4-mm inner temporal clear corneal openings (stretch incision); 77 patients received 5-mm PMMA lenses through temporal clear corneal incisions of 4.1-mm outer and 6.5-mm inner diameter incisions. Corneal topography was examined in all patients before the operations as well as 3 days and 6 months after the operations. Results: 6 months after the operations, we observed a surgically induced astigmatism of 0.4 ± 0.2 dpt for the 3.2-mm incisions compared to 0.8 ± 0.7 dpt for the 4.1-mm incisions; evaluation according to Holladay of the preoperative spherical corneas yielded a with-the-wound change of 0.0 ± 0.3 dpt after 3.2-mm incisions versus 0.6 ± 0.7 dpt after 4.1-mm incisions. The difference in astigmatism for the two types of incisions was statistically significant (p = 0.001). Conclusion: Acrysof lens implantation is especially useful for patients with spherical corneas because of avoidance of postoperative astigmatism. The 4.1-mm corneal incision using PMMA lens implants can be used on the steep meridian to reduce preoperative astigmatism.

One year follow-up of astigmatism after 4.0 mm temporal clear corneal and superior scleral incisions

PurposeTo compare the effect of 2 contemporary sutureless cataract surgery incisions on corneal astigmatism 1 year after surgery. SettingOutpatient Clinic, Department of Ophthalmology, Vejle Hospital, Denmark. MethodsSixty-nine patients who had cataract surgery in 1997 with a 4.0 mm temporal clear corneal (n = 32) or superior scleral (n = 37) incision were examined 1 year postoperatively. Surgically induced astigmatism was analyzed by vector analysis, vector decomposition, and polar values using preoperative and postoperative keratometric readings. ResultsVector analysis revealed a slightly lower median induced cylinder in the clear corneal patients; 0.41 diopter (D) (95% confidence limits [CL] 0.24 to 0.67 D) versus 0.61 D (95% CL 0.49 to 0.73 D) (P < .05). Decomposition of the induced cylinder (against the rule/total) showed statistically significant differences in the direction of the cylinder; 0.21 (95% CL 0.03 to 0.41) versus 0.90 (95% CL 0.82 to 0.95) (P < .00001). The directional difference was confirmed by polar values. ConclusionBoth incisions induced low and comparable amounts of astigmatism. The directional differences were modest. Findings in previous studies of a poor outcome after clear corneal incisions were not confirmed in this long-term follow-up.

Inflammation after phacoemulsification in patients with type 2 diabetes mellitus without retinopathy: Prospective study

Purpose: To evaluate inflammation after clear corneal incision (CCI) cataract surgeryin patients with noninsulin-dependent diabetes mellitus and no retinopathy. Methods: Forty patients with diabetes and 40 age-matched controls had standardized temporal CCI cataract surgery with implantation of a foldable intraccular lens. Anterior chamber flare was evaluated in an undilated eye with a laser flare-cell meter preoperatively and 1, 3, 7, 14; and 28 days postoperatively. Results: In both groups, flare and cell values increased on the first postoperative dayand successively decreased on the following days. Flare had not recovered to preoperative values by day 28. At no time was there a significant mean difference in cell and flare between the 2 groups. Conclusion: It does not appear necessary to alter the postoperative therapeuticregimen in patients with type 2 diabetes mellitus and no retinopathy.

One-site versus 2-site phacotrabeculectomy:A randomized study

Purpose: To compare 1-site and 2-site combined phacoemulsitication with foldable intraocular lens (IOL) implantation and trabeculectomy Setting: El-Maghraby Eye Hospital, Jeddah, Saudi Arabia. Methods: Seventy-six eyes with coexisting cataract and glaucoma were randomwith phacoemulsification and foldable IOL implantation through the same (1-site group) or a separate; temporal clear corneal incision (2-site group) Postoperative evaluation included visual acuity, intraocular pressure, (IOL bleb) assessment, and number of antiglaucoma medications. Follow-up 12 to 18 months. Results: Mean preoperative IOP was 28.1 mm Hg ± 7.1 (SD) in the 2-site group and 26.2 ± 6.5 mm Hg in the 1-site group. At 6 months postoperatively mean IOP was 16.9 ± 4.3 and 16.8 ± 3.8 mm Hg, respectively ( P = () and at 12 months, 3.3 and 19.1 ± 3.1 mm Hg, respectively ( P = 044). Twenty-three of 39 eyes in the 2-site group and 14 of 37 (38%) in the T-site group had clinically apparent filtering blebs at 12 months ( P = .065). Postoperative astigmatic change and complications were comparable. Conclusion: Mitomycin-C trabeculectomy superiorly combined with separate temporalclear corneal phacoemulsification provided 1 year IOP control comparable to that with single-incision (1-site) combined cataract and glaucoma surgery.

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.

Comparison of surgically induced astigmatism after sutureless temporal clear corneal and scleral frown incisions

Purpose: To compare the corneal astigmatic changes induced by clear corneal incisions with those induced by scleral tunnel frown incisions, both from a temporal approach, in sutureless cataract surgery.Setting: Department of Ophthalmology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China.Methods: This prospective study comprised 120 eyes divided into two groups of 60 each based on incision type. All patients had examinations with an autokeratometer preoperatively and 1 week and 1, 3, and 6 months postoperatively.Results: Simple subtraction of the scalar analysis in each group showed minimal astigmatic changes; however, the standard deviation of astigmatic change was greater in the clear corneal incision group. The mean vector analysis of surgically induced astigmatism in the scleral frown incision group was 0.69, 0.75, 0.72, and 0.61 diopter (D) at 1 week and 1, 3, and 6 months, respectively. In the clear corneal incision group, it was 1.55, 1.12, 0.93, and 0.92 D at the same intervals. In the scleral frown incision group, Naeser's polar value also showed minimal changes in polar astigmatism throughout the study; in the clear corneal incision group, it showed a mean with-the-rule (WTR) astigmatic shift of +0.73, +0.22, +0.13, and +0.08 D at 1 week and 1, 3, and 6 months, respectively.Conclusion: Corneal stability was achieved with minimal astigmatic change 1 week after scleral frown incisions, while clear corneal incisions induced greater WTR astigmatism with delayed stabilization 1 to 3 months postoperatively.

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 a 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.

Batch-by-batch analysis of topographic changes induced by sutured and sutureless clear corneal incisions

Purpose: To evaluate the effect of a suture on surgically induced corneal topographic changes in 5.0 mm clear corneal incisions.Setting: University Eye Hospital, Vienna, Austria.Methods: Thirty-seven eyes that had cataract surgery were included in the prospective study. A 5.0 mm long and 0.3 mm deep precut was followed by preparation of a corneal tunnel. After phacoemulsification and intraocular lens implantation, the self-sealing wound was left unsutured in 19 eyes; one radial 11-0 nylon suture was applied in 18 eyes. Using a TMS-1 videokeratoscope, corneal topography was measured preoperatively and at 1 week and 1 and 3 months postoperatively. The topographic data were evaluated by statistical batch-by-batch analysis. Each topographic image was cut into 178 fields in eight concentric rings. The refractive values of these fields were stored in a database. Differences between the four readings of each patient were calculated and the mean differences of the 178 fields in each group were transformed into color-coded maps. The significance of topographical changes and group comparisons of induced changes were computed by Wilcoxon tests.Results: Both groups exhibited significant temporal flattening and vertical steepening. The unsutured eyes also displayed significant nasal flattening. Sutureless 5.0 mm clear corneal incisions induced significantly more vertical steepening and nasal flattening than sutured incisions.Conclusion: Application of one radial 11-0 nylon suture in 5.0 mm temporal clear corneal incisions significantly reduced shape changes in the nasal corneal region.

Long-term endothelial cell loss following phacoemulsification through a temporal clear corneal incision

Purpose: To evaluate central endothelial cell loss (ECL) following clear corneal cataract surgery using two different incision sizes and the effect of ultrasound time (UST) and power on postoperative ECL and various cell parameters.Methods: Fifty-eight patients had phacoemulsification through temporal, two-step clear corneal tunnel incisions. In Group A (n = 28), a one-piece, plate-haptic, foldable silicone intraocular lens (IOL) was implanted through a 3.5 mm sutureless incision. In Group B (n = 30), a poly(methyl methacrylate) IOL was implanted through a 5.0 mm incision with one radial suture. The central endothelial cell counts were recorded preoperatively and postoperatively at 2 to 5 days, after 6 months, and after 1 year. Color-coded, computer-assisted specular microscopy was used for special cell analysis after 1 year.Results: Collective data showed an ECL of 7.9 ± 4.1 % (mean ± standard deviation) at 2 to 5 days postoperatively, 6.7 ± 2.9% after 6 months, and 7.3 ± 3.3% after 1 year. A direct linear relationship was found between ECL and UST and power: ECL increased as UST and power increased. After 1 year, ECL in Group A was 4.2% with UST ≤1 1/2 minutes, 6.7% with UST ≥ 1 1/2 to 2 1/2 min, and 9.6% with UST > 2 1/2 to 3 1/2 min; in Group B, it was 6.0%, 7.5%, and 11.4%, respectively. Specular microscopy showed normal, age-related cell parameters 1 year postoperatively.Conclusions: Phacoemulsification with 3.5 mm clear corneal incisions produced slightly less ECL (6.7%) than phacoemulsification with 5.0 mm incisions (7.9%). Total ECL of 7.3% at 1 year postoperatively compared favorably with ECL rates of other cataract extraction methods.

Bacterial anterior chamber contamination with foldable silicone lens implantation using a forceps and an injector

Purpose: To compare the rate of anterior chamber (AC) contamination during implantation of a foldable three-piece silicone lens using a forceps and an injector.Setting: Department of Ophthalmology, University of Saarland, Homburg (Saar), Germany.Methods: In a prospective, randomized study, we cultured AC aspirates of patients who had phacoemulsification with silicone lens implantation through a 3.5 mm temporal clear corneal incision. In Group A, the lens was implanted with a forceps and in Group B, with an injector. Immediately after lens implantation, the AC aspirate (0.05 to 0.10 ml) was collected and sent to the microbiology department. All cultures were incubated for 3 days. As a topical antibiotic, gentamicin was given preoperatively and intraoperatively.Results: One hundred patients (50 in each group) were examined. In each group the bacterial contamination of the AC was 2%.Conclusion: Bacterial contamination of the AC was not significantly different after silicone lens implantation with a forceps and with an injector.

Long-term course of induced astigmatism after clear corneal incision cataract surgery

Purpose: To determine whether a small clear corneal temporal incision produces less surgically induced astigmatism than a larger incision.Methods: One hundred three consecutive cases of postoperative astigmatism after clear corneal incision cataract surgery were studied for a minimum of 1 year. Only self-sealing incisions from the temporal side were made as follows: 3.2 mm (Group A); 4.0 mm (Group B); 5.2 mm (Group C). We considered the amount and axes of the keratometric readings at different times as well as their course over time. Induced astigmatism was calculated using three methods. Axial changes were also analyzed.Results: Immediately after the surgery, there was a small, surgically induced, withthe-rule astigmatic shift in all groups, which in most cases decreased to near preoperative levels with time. One year postoperatively, mean induced astigmatism was 0.09 diopter (D) in Group A, 0.26 D in Group B, and 0.54 D in Group C. Most cases had minimal axial changes. In Group A, 86% had an axial change of fewer than 30 degrees; in Group B, 76%; and in Group C, 73%.Conclusion: The smallest incision group had the least surgically induced astigmatism and axial change. All incision groups remained stable and had satisfactory clinical results.

Endothelial Cell Loss After 3.5 mm Temporal Clear Corneal Incision and 3.5 mm Superior Scleral Tunnel Incision

OBJECTIVE: To undertake a comparative study of endothelial cell loss after 3.5 mm temporal clear corneal incisions (tCCI) and 3.5 mm superior scleral tunnel incisions (sSTI). STUDY DESIGN: Besides the site and preparation of the incision all 59 eyes were operated with the same surgical technique and implantation of a flexible silicone intraocular lens (IOL) through a 3.5 mm incision. In group 1 a temporal clear corneal incision and in group 2 a superior scleral tunnel incision were prepared. Endothelial cell density was measured preoperatively and 6 months after surgery with a contact specular microscope (Konan®). The results were compared and statistically analysed. RESULTS: Mean endothelial cell loss was 8.1% in group 1 and 3.0% in group 2. Even though relevant differences were found between the 2 groups, in statistical analysis the significance was ‘borderline’ (P < 0.0964). CONCLUSIONS: Even though CCI is a promising surgical technique with high beneficial influence on surgery and postoperative outcome, an increased central endothelial cell loss may be expected after surgery. Because of this fact, in the opinion of the authors, this technique should be avoided in cases with very hard cataracts and/or in cases with low preoperative endothelial cell density. As shown in the literature, when performing a CCI it is advisable to create the incision at the temporal site and not at the superior site which is close to the central corneal region.

PMMA Implants via Temporal Clear Corneal Incisions: Concern Replaces Confidence

OBJECTIVE: A prospective study to compare two methods of closure of long temporal clear corneal incisions used for implantation of PMMA lenses. STUDY DESIGN: Twenty-eight patients had their incisions closed by either suturing with 10-0 vicryl or hydration of the anterior lip of the corneal entry. SETTING: Private practice Vernon, B.C. Canada. Patients: Individuals presenting in a solo practitioners office for senile cataract surgery. OUTCOME MEASURES: Incidence of hypotony, posterior capsule tears, iris fray, astigmatic shift and bacterial infections. RESULTS: No hypotony was detected, posterior capsule tear and iris fray each occurred in two cases, astigmatic shift to against the rule in 50% of cases, bacterial infection of suture penetration site in two and endophthalmitis in one. CONCLUSIONS: Patients had less pain with hydration of the anterior lip of the incision but two stitch abscesses and one bacterial endophthalmitis led to abandonment of clear corneal incisions for PMMA lens implantation with replacement by temporal scleral tunnel incisions. Infected patients made excellent recoveries but three bacterial infections in twenty-eight procedures is an unacceptable incidence of such a potentially severe complication.

Computerized Statistical Analysis of Corneal Topography for the Evaluation of Changes in Corneal Shape After Surgery

We examined 20 patients for the effect of a 3-mm sutureless temporal clear corneal incision cataract operation on corneal topography, as recorded with the computer-assisted video-keratoscope TMS-1 (Computed Anatomy, Inc., New York, New York). Each topographic image was cut into 178 fields in eight concentric rings. The refractive values of these fields were stored in a database. The mean differences between the preoperative and one-month postoperative findings were calculated and transformed into color-coded maps as output for the statistical analysis. The patients operated on showed a mean flattening of 0.4 to 1.0 diopter in the temporal region. This was statistically significant by paired Wilcoxon signed-rank tests. There was no significant vertical steepening or nasal flattening, except in two isolated fields. For control purposes, we twice examined 20 age-matched volunteers who were not operated on. The paired Wilcoxon tests of this group did not show significant changes. When compared with Cravy's vector analysis, induced topographic change analysis is better at evaluating surgically induced corneal shape changes.