Viscoelastic-Induced Interlamellar Stromal Keratopathy (VISK) during Cataract Surgery in a Patient with a History of Laser in situ Keratomileusis.

A 47-year-old patient status post uncomplicated bilateral LASIK treatment presented with interlamellar stromal keratopathy induced by viscoelastic material during cataract surgery, decreasing her vision to CF (count fingers) postoperatively. After recognition, the viscoelastic material was removed by interface irrigation. The keratopathy improved by postoperative day 1 and resolved by 6 weeks with best-corrected visual acuity being 20/30. We conclude that viscoelastic-induced stromal keratopathy requires correct recognition in order to undertake appropriate management.

Simplified, Readily Available Method for the Treatment of Band Keratopathy With Ethylenediaminetetraacetic Acid.

PURPOSE: To compare 3 methods for creating ethylenediaminetetraacetic acid (EDTA) solution using readily available Vacutainer tubes for the treatment of band keratopathy. METHODS: All 3 protocols used commercially available Vacutainer blood collection tubes coated with K2EDTA. An osmometer was used to measure and compare the concentration of EDTA created using 3 different protocols. The time required for preparation of the solution was measured and compared to evaluate its efficiency for everyday clinical use. In addition, volume of EDTA solution obtained was measured for method 1. The most promising protocol for clinical use was then used for treatment of a series of patients. RESULTS: Average osmolarity was 532, 285, and 422 for methods 1, 2, and 3, respectively (ANOVA P < 0.01, all Tukey honestly significant difference P < 0.01). For the respective mixtures, average concentration was 65, 35, and 52 mg/mL, and average time to create solution was 189, 38, and 83 seconds (ANOVA P < 0.01, all Tukey honestly significant difference P < 0.01). The most promising, method 3, was found to be safe and effective in removing calcium from the corneal stroma in a series of 5 patients with 6 eyes treated. It also yielded 25% more solution for clinical use than method 1. CONCLUSIONS: Method 3 using a single 10-mL Vacutainer tube with 18 mg of K2-EDTA had the best balance of effective concentration of EDTA, time to preparation, and simplicity of methodology, when compared with previously published methods 1 and 2. It also yielded a greater final volume of solution.

Iris fixation of unstable anterior chamber intraocular lenses.

UNLABELLED: Cataract surgeons are sometimes challenged with a patient who has an unstable anterior chamber intraocular lens (AC IOL). Over time, an unstable AC IOL can lead to significant complications. This problem is most often addressed with an IOL exchange using an appropriately sized AC IOL or a posterior chamber IOL with iris or scleral fixation. We present a technique of 2-point iris fixation of unstable AC IOLs as a simpler and less traumatic alternative. FINANCIAL DISCLOSURE: Neither author has a financial or proprietary interest in any material or method mentioned.

Reversed needle pass clear-corneal or limbal incision suturing technique using the 3-throw (1-1-1) adjustable square knot.

A single radial suture is required for a corneal or limbal incision that does not seal despite stromal hydration. In the traditional technique for placing this suture, the needle enters from the corneal side of the limbal incision and exits toward the scleral side and the suture is usually tied with a 3-1-1 surgical knot. We present an improved suturing technique in which the needle path is reversed. The needle enters on the scleral side of the limbal incision, exits on the corneal side toward the apex, and is tied with an adjustable 1-1-1 knot.

Intraoperative cyclorotation and pupil centroid shift during LASIK and PRK.

PURPOSE: To determine the degree of cyclorotation and centroid shift in the x and y axis that occurs intraoperatively during LASIK and photorefractive keratectomy (PRK). METHODS: Intraoperative cyclorotation and centroid shift were measured in 63 eyes from 34 patients with a mean age of 34 years (range: 20 to 56 years) undergoing either LASIK or PRK. Preoperatively, an iris image of each eye was obtained with the VISX WaveScan Wavefront System (Abbott Medical Optics Inc) with iris registration. A VISX Star S4 (Abbott Medical Optics Inc) laser was later used to measure cyclotorsion and pupil centroid shift at the beginning of the refractive procedure and after flap creation or epithelial removal. RESULTS: The mean change in intraoperative cyclorotation was 1.48±1.11° in LASIK eyes and 2.02±2.63° in PRK eyes. Cyclorotation direction changed by >2° in 21% of eyes after flap creation in LASIK and in 32% of eyes after epithelial removal in PRK. The respective mean intraoperative shift in the x axis and y axis was 0.13±0.15 mm and 0.17±0.14 mm, respectively, in LASIK eyes, and 0.09±0.07 mm and 0.10±0.13 mm, respectively, in PRK eyes. Intraoperative centroid shifts >100 µm in either the x axis or y axis occurred in 71% of LASIK eyes and 55% of PRK eyes. CONCLUSIONS: Significant changes in cyclotorsion and centroid shifts were noted prior to surgery as well as intraoperatively with both LASIK and PRK. It may be advantageous to engage iris registration immediately prior to ablation to provide a reference point representative of eye position at the initiation of laser delivery.

Pupil dilation using a standard cataract surgery regimen alone or with atropine 1.0% pretreatment: prospective comparative evaluation.

PURPOSE: To compare the amount of pupil dilation produced by a set of commonly used preoperative mydriatic agents for cataract surgery, with the same regimen preceded by topical administration of atropine 1.0%. SETTING: Department of Ophthalmology, Loma Linda University, Loma Linda, California, USA. METHODS: In this prospective unmasked study, the baseline pupil size in eyes of volunteers was measured. Pupil size was then measured 30 minutes after instillation of the institution's standard dilation regimen for cataract surgery, which included phenylephrine 2.5%, tropicamide 1.0%, and cyclopentolate 1.0%. Several days later, the subjects returned for repeat measurements after pretreating the study eye(s) with atropine 1.0% 3 times a day the day previously and once on the morning of repeat dilation and measurements. Pupil size was again measured after administration of the standard regimen. RESULTS: The study included 72 eyes of 54 patients. A paired t test showed a statistically significant difference in mean pupil dilation between the standard regimen alone and the standard regimen with atropine 1.0% pretreatment. The mean pupil dilation was 7.3 mm +/- 1.2 (SD) with the standard regimen alone and 6.9 +/- 1.2 mm with the standard regimen with atropine pretreatment; the difference was statistically significant (P<.001). CONCLUSION: The addition of atropine 1.0% 1 day before administration of a standard preoperative dilating regimen for cataract surgery resulted in a smaller dilated pupil diameter than administration of the standard set of preoperative mydriatic agents alone. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Prospective randomized evaluation of short-term complications when using buffered or unbuffered lidocaine 1% with epinephrine for blepharoplasty surgery.

PURPOSE: To determine whether there is a difference in the incidence of short-term complications using plain lidocaine with epinephrine versus the buffered equivalent in eyelid surgery. METHODS: The authors performed a prospective, double-masked, randomized study in patients scheduled for combined upper eyelid blepharoplasty and levator advancement ptosis repair surgery with local anesthesia. Exclusion criteria included: documented allergies to lidocaine and/or epinephrine; known pregnancy; profound cognitive impairment; inability to understand the visual analog scale or the informed consent; and previous eyelid surgery. Each subject was his/her own control by using the unbuffered local anesthetic in one eye, while the buffered solution was used in the other eye. The surgeon completed a specific standardized data collection form for quantifying both intraoperative and postoperative complications, such as bleeding, bruising, and edema. Data regarding pain on injection and postoperative pain were collected from patients using a visual analog pain scale. RESULTS: Thirty-nine patients were included in this study, of which 18 experienced less pain during the injection on the side where buffered lidocaine was used, 11 reported no difference, and 10 reported less pain in the eye injected with unbuffered lidocaine. Injection pain revealed a mean operative pain rating of 4.01 +/- 2.45 in the eye with buffered lidocaine versus 4.49 +/- 2.58 in the control (p = 0.06). There were no significant differences between the buffered and unbuffered lidocaine eyes as regards postoperative bleeding, swelling, or pain, and there was a trend toward less pain on injection with the buffered solution. CONCLUSIONS: There were no significant differences in postoperative pain, swelling, or bleeding with the use of plain versus buffered lidocaine in eyelid surgery. There was a trend for the buffered anesthetic to cause less pain on injection.

Simplified technique for combined silicone oil removal during phacoemulsification with standard or toric intraocular lens implantation.

We describe a simple automated technique for silicone oil removal at the time of phacoemulsification combined with standard or toric intraocular lens implantation using the phacoemulsification handpiece in irrigation/aspiration mode. No additional corneal or scleral incisions are needed, and no specialized vitreoretinal instrumentation is required.

Comparison of the VISX wavescan and NIDEK OPD-scan aberrometers.

PURPOSE: To compare measurements obtained with the VISX WaveScan and NIDEK OPD-Scan (ARK 10000). METHODS: The VISX WaveScan is a wavefront aberrometer that uses Hartmann-Shack technology. The NIDEK OPD-Scan uses time-based retinoscopy (dynamic skiascopy). Measurements taken of 92 eyes from 51 patients using both aberrometers were retrieved and compared. Measurements included sphere, cylinder, axis, and Zernike coefficients of second to sixth radial order aberrations. The Zernike coefficients were normalized to a 6.0-mm pupil and used to calculate the root-mean-square (RMS) values of the radial orders, angular orders, total higher order aberrations, third order trefoil, third order coma, total spherical aberration, and total coma. Paired t tests were used to compare differences between measurements. RESULTS: Although no significant difference was found between the NIDEK OPD-Scan and subjective manifest refraction in sphere and axis, the NIDEK OPD-Scan measured significantly higher cylinder. No significant difference was found between the VISX WaveScan and subjective manifest refraction. The NIDEK OPD-Scan had significantly lower total higher order, second radial order, third order coma, total spherical aberration, total coma, and second angular order RMS values. The VISX WaveScan had significantly lower cylinder, trefoil, third-angular order, and fifth-angular order RMS values. CONCLUSIONS: Specific and significant differences were noted between the measurements taken by the VISX WaveScan and NIDEK OPD-Scan wavefront aberrometers.

Comparison of central corneal thickness measurements by ultrasound pachymetry, konan noncontact optical pachymetry, and orbscan pachymetry.

PURPOSE: To assess the repeatability of two optical techniques for measurement of central corneal thickness and to compare the validity of these techniques with standard ultrasound pachymetry. METHODS: Corneal thickness was measured twice with Konan optical pachymetry, Orbscan optical pachymetry, and 3 times by conventional ultrasound pachymetry in 100 eyes of 50 healthy volunteers between the ages of 22 and 74 years. The repeatability of measurements of each instrument was determined and compared. Validity was determined by comparing the means of the first Konan and Orbscan measurements to the mean of standard ultrasound pachymetry. Intraclass correlation coefficients (ICCs) were calculated, and their confidence intervals (CIs) were determined. RESULTS: Repeatability of ultrasound pachymetry had an ICC of 0.905 (95% CI: 0.870-0.932). The Konan pachymeter had an ICC of 0.947 (95% CI: 0.922-0.964), and the Orbscan pachymetry yielded an ICC of 0.972 (95% CI: 0.959-0.981). Validity of Konan pachymetry had an ICC of 0.730 (95% CI: 0.623-0.810). Orbscan pachymetry had an ICC of 0.865 (95% CI: 0.805-0.907). CONCLUSIONS: Both of the newer optical methods for determining corneal thickness produced measurements of greater repeatability than the standard ultrasound technique. Orbscan pachymetry provides greater repeatability (P = 0.02) and validity (P = 0.007) than the Konan optical pachymeter.

Comparing immersion ultrasound with partial coherence interferometry for intraocular lens power calculation.

BACKGROUND AND OBJECTIVE: To compare the utility and accuracy of high-precision immersion ultrasound, partial coherence interferometry, and the IOL Master system (Carl Zeiss Meditec, Dublin, CA) in a tertiary care referral center. PATIENTS AND METHODS: Comparative clinical study in a tertiary care, multispecialty, university practice. Participants were consecutive patients scheduled for cataract surgery at Emory Eye Center. Patients underwent biometry using immersion ultrasound, partial coherence interferometry, and the IOL Master system. RESULTS: Twenty-two percent of eyes undergoing surgery could not be measured using interferometry. In those eyes measurable by both methods, there was no difference in measurements nor postoperative refractive outcome. Each method had a high repeatability (intraclass correlation coefficient > 0.99) with a high intraclass correlation between methods (intraclass correlation coefficient = 0.99). CONCLUSIONS: When it can be used, interferometry is equivalent to immersion ultrasonography regarding biometric accuracy and precision. However, it cannot replace ultrasonography, especially for eyes with dense media opacity.

Laser in situ keratomileusis for spherical hyperopia and hyperopic astigmatism using the NIDEK EC-5000 excimer laser.

PURPOSE: To assess the efficacy, predictability, and safety of LASIK for the surgical correction of low to moderate hyperopia and hyperopic astigmatism using the NIDEK EC-5000 excimer laser. METHODS: In a multicenter United States Food and Drug Administration (FDA) regulated study of LASIK, 7 centers enrolled 293 eyes with manifest refraction sphere that ranged from +0.50 to +6.00 diopters (D) with or without astigmatism up to 3.00 D. The intended outcome was plano in all eyes. Patients were treated bilaterally. One year postoperative outcomes are reported. RESULTS: The mean spherical equivalent refraction (MRSE) for all eyes changed from +3.51 +/- 1.45 [corrected] D (range: +0.50 to +6.63 D) preoperatively to +0.35 +/- 0.54 D (range: +1.63 [corrected] to +2.00 D) 1 year [corrected] Overall, 61% (170/279) of eyes achieved distance uncorrected visual acuity (UCVA) of 20/20 or better, 82% (228/279) of eyes saw 20/25 or better, and 99% (277/279) of eyes saw 20/40 or better. Refractive accuracy was demonstrated as 63.1% (176/279) of eyes achieved a MRSE within +/- 0.50 D and 90.3% (252/279) of eyes within +/- 1.00 D. Less than 2% (4/279) of eyes lost 2 lines of distance best spectacle-corrected visual acuity. Stability of refraction was demonstrated by 6 months, with a mean hyperopic shift of < 0.03 D from 3 to 6 months. CONCLUSIONS: The NIDEK EC-5000 corrected hyperopia and hyperopic astigmatism with UCVA, refractive accuracy, 1-year stability, and safety that surpassed all FDA criteria.

Case of corneal melting associated with the use of topical nepafenac.

PURPOSE: To report a case of corneal melting associated with the use of the topical nonsteroidal anti-inflammatory agent Nepafenac. METHODS: Case report and literature review. RESULTS: A 62-year-old woman with a complicated ocular history developed corneal melting associated with the use of Nepafenac. On discontinuation of Nepafenac, the melt rapidly resolved. CONCLUSIONS: Topical nonsteroidal anti-inflammatory agents have been associated with corneal ulceration and stromal melts. This is, to our knowledge, the first reported case involving the new agent, Nepafenac.

Accuracy of intraocular lens power prediction using the Hoffer Q, Holladay 1, Holladay 2, and SRK/T formulas.

PURPOSE: To compare the accuracy of intraocular lens (IOL) power calculations using 4 formulas: Hoffer Q, Holladay 1, Holladay 2, and SRK/T. SETTING: Tertiary care center. METHODS: This study was a retrospective comparative analysis. Immersion ultrasound biometry (axial length, anterior chamber depth, and lens thickness), manual keratometry, and postoperative manifest refraction were obtained in 643 eyes of consecutive patients who had routine uneventful cataract surgery with implantation of 1 of 2 IOLs using the same operative technique by the same surgeon. Biometric data were entered into each of the 4 IOL power calculation formulas, and the results were compared to the final manifest refraction. An optimized lens constant was used for each formula. Results were also stratified into groups of short, average, medium long, and very long axial length <22.0 mm, 22.0 to <24.5 mm, 24.5 to 26.0 mm, and >26.0 mm, respectively). RESULTS: No formula was more accurate than the others as measured by mean absolute error. The formulas were also equally accurate when eyes were stratified by axial length. CONCLUSION: The 4 IOL power formulas provided equivalent refractive results in the entire group of eyes and in the subsets of axial lengths tested.

Comparison of 2 multiple-measurement infrared pupillometers to determine scotopic pupil diameter.

PURPOSE: To compare a monocular and a binocular multiple-measurement digital infrared pupillometers for measuring scotopic pupil diameter. SETTING: Department of Ophthalmology, Loma Linda University, Loma Linda, California, USA. METHODS: Scotopic pupil size was measured after 1 minute of dark adaptation in 42 eyes of 21 volunteers. Measurements were taken twice each with 2 multiple-measurement digital infrared pupillometers, the monocular pupillometer (Neuroptics, Inc.), and the binocular pupillometer (P2000D, Procyon, Ltd.) Intraclass correlation coefficients (ICC) and limits of agreement (LOA) were used to measure repeatability and agreement of measures with each instrument and between instruments. The Wilcoxon signed rank test was used to compare variability of measurements within each instrument. RESULTS: The mean scotopic pupil size was 4.79 mm +/- 0.95 (SD) with the Procyon and 4.86 +/- 0.93 mm with the Neuroptics. Repeatability and agreement tests for the Procyon measures showed the following: ICC, 0.954; 95% confidence interval (CI), 0.916-0.975; LOA, -0.60 to 0.56; range, 1.16. The Wilcoxon signed rank test of variability gave a Z score of -2.53 (P = .01, 2 tailed). The repeated measures testing with the Neuroptics pupillometer showed the following: ICC, 0.985; 95% CI, 0.972-0.992; LOA, -0.39 to 0.26; range, 0.64; Z score, -1.15 (P = .25, 2-tailed). Repeatability and agreement tests for measures between instruments showed the following: ICC, 0.954; 95% CI, 0.916-0.975; LOA, -0.60 to 0.50; range 1.11. CONCLUSIONS: There was a high repeatability and agreement in scotopic pupil diameter for repeated measures within each device and measurements between the devices. Differences in variability in scotopic pupil diameter evaluated by the Wilcoxon signed rank test were significant only with the Procyon pupillometer.

Late-onset traumatic dislocation with central tissue loss of laser in situ keratomileusis flap.

PURPOSE: We report the occurrence and outcome of a severe late-onset traumatic dislocation of a laser in situ keratomileusis (LASIK) flap with loss of central flap tissue. METHODS: Case report. RESULTS: A 40-year-old woman underwent uncomplicated bilateral LASIK surgery, followed 5 years later by an enhancement procedure in both eyes. Ocular trauma with a power sander occurred 6 years after LASIK and 1 year after the enhancement procedure. The flap was found to have an almost complete tear from the nasal hinge and a central tissue defect. After irrigating, repositioning, and stabilizing the flap with 2 nylon sutures, a bandage contact lens was placed. The patient was treated with topical antibiotic and steroid drops. Stage 2 diffuse lamellar keratitis developed, which responded to topical treatment. Ten weeks after injury, the patient regained an uncorrected visual acuity of 20/20-1. CONCLUSION: Late-onset trauma to the LASIK flap can result in flap dehiscence and tissue loss. Prompt and appropriate management can lead to an excellent visual outcome even in severely traumatized dislocated LASIK flaps.

Treatment of epithelial ingrowth after LASIK enhancement with a combined technique of mechanical debridement, flap suturing, and fibrin glue application.

PURPOSE: To report a case of clinically significant post-laser in situ keratomileusis (LASIK) epithelial ingrowth successfully treated with a combined technique of mechanical debridement, flap suturing, and fibrin glue application. METHODS: A retrospective case report. RESULTS: A 42-year-old female patient underwent LASIK and an enhancement procedure in 1998 and 2002, respectively. Two years after her enhancement, she developed severe, visually significant epithelial ingrowth. Treatment was undertaken using a combination of mechanical debridement, flap suturing, and fibrin glue application. No recurrence was found during a 15-month follow-up period. No adverse effects were seen with this approach. CONCLUSION: Severe progressive epithelial ingrowth may be treated successfully with a combination of mechanical debridement, flap suturing, and fibrin glue application.

Negative dysphotopsia associated with implantation of the Z9000 intraocular lens.

Uneventful small-incision cataract surgery was performed in a 70-year-old man and a 62-year-old woman with implantation of a Tecnis Z9000 intraocular lens (IOL) (Pharmacia). No ocular pathology was present in the patients preoperatively. Unsolicited complaints of negative dysphotopsia were made postoperatively, and the symptoms have persisted for more than 1 year in both patients. Symptomatic negative dysphotopsia may be seen in association with the Z9000 IOL.

Emerging therapies for herpes viral infections (types 1 - 8).

There are eight members of the herpesviridae family: herpes simplex virus-1 (HSV-1), HSV-2, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, human herpes virus-6, human herpes virus-7 and human herpes virus-8. The diseases caused by viruses of the herpesviridae family are treated with and managed by systemic and topical antiviral therapies and immunomodulating drugs. Because these viruses establish a latent state in hosts, antiherpetic agents, such as nucleoside analogues, only control symptoms of disease or prevent outbreaks, and cannot cure the infections. There is a need for treatments that require less frequent dosing, can be taken even when lesions are more advanced than the first signs or symptoms, and can treat resistant strains of the viruses without the toxicities of existing therapies. Immunomodulating agents, such as resiquimod, can act on the viruses indirectly by inducing host production of cytokines, and can thereby reduce recurrences of herpes. The new helicase primase inhibitors, which are the first non-nucleoside antiviral compounds, are being investigated for treatment of HSV disease, including infections resistant to existing therapy.

Prospective, randomized trial of diclofenac and ketorolac after refractive surgery.

PURPOSE: To compare the effectiveness of diclofenac and ketorolac in relieving corneal pain after refractive surgery, and determine if there is a difference in stinging on instillation. METHODS: Thirty patients were randomized prospectively to postoperative diclofenac in one eye and ketorolac in the other. Patients and surgeon did not know which medications were used. Ocular postoperative pain and discomfort on instillation of medication were measured after radial keratotomy with a visual analog scale and a questionnaire. RESULTS: Both medications were highly effective in relieving pain. There was no significant difference in pain relief, or stinging on instillation (P = .29). CONCLUSION: There was no statistical difference in the effectiveness of the medications on pain relief, or in stinging on instillation.