Marsha G. Raanan

Unpreserved lidocaine to control discomfort during cataract surgery using topical anesthesia

Purpose: To determine whether intraoperative unpreserved lidocaine further decreases discomfort or pain during sutureless small incision cataract surgery and intraocular lens (IOL) implantation under topical anesthesia. Setting: Outpatient ambulatory surgical center. Methods: In this prospective controlled study, comparable eligible patients were randomized to receive 0.1 cc unpreserved lidocaine 1 % or 0.1 cc balanced salt solution (BSS®) (control group) in double‐masked fashion. Study drugs were injected intracamerally 1 minute before phacoemulsification. A predefined uniform pain/discomfort scale was used for assessment during phacoemulsification and IOL insertion. A secondary study using a 0.5 cc dose was also performed. Results: Twenty‐six percent in the control group and 9% in the lidocaine group had discomfort pain scores of 2 or more; 10% in the BSS group felt increased pressure or pain during phacoemulsification. In the lidocaine group, discomfort was felt mainly during IOL insertion, possibly as a result of wound manipulation. During phacoemulsification, no patient in the lidocaine group reported pain; 2% felt increased pressure during phacoemulsification. A dose increase to 0.5 cc reduced any intraocular sensation to 3% in the lidocaine group. No patient in either group had significant cell loss or adverse events. Conclusion: Intraoperative lidocaine is safe and effective in controlling intraoperative discomfort.

Comparison of the SRK/T formula and other theoretical and regression formulas

ABSTRACT We compared the predictive accuracy of the SRK/T formula to the SRK II, Binkhorst H, Hoffer, and Holladay formulas in seven series of cases totaling 1,050 eyes. In the combined group, the SRK/T and Holladay formulas performed only slightly better than the other formulas. In short eyes (< 22 mm), all formulas performed well, with the SRK/T, SRK II, and Holladay formulas performing marginally better. In moderately long eyes (> 24.5 mm, ≤ 27 mm), the Hoffer and Binkhorst II formulas had a greater proportion of cases with > 2 diopters (D) of error and the SRK/T and Holladay were again marginally better. In the very long eyes (> 27 mm and < 28.4 mm), there were only 11 cases and all formulas performed well since none had > 2 D of prediction error. In an extremely long eye data set (> 28.4 mm), the SRK II formula clearly gave the poorest result. Eyes of this length occurred in only 0.1% of cases in our unselected series. Results support the contention that the present second and third generation IOL power formulas give fairly equivalent accuracy Other factors, such as availability, ease of use, and ability to tailor or individualize, become major considerations.

Visual and Refractive Results of Multifocal Intraocular Lenses

One hundred forty-nine selected patients with bilateral multifocal intraocular lenses (IOLs) were evaluated and compared retrospectively with 131 patients with bilateral monofocal IOLs. Seventy-eight percent of multifocal cases and 74.8% of monofocal cases had uncorrected visual acuity of 20/40 or better. Fifty-four percent of multifocal cases had near uncorrected visions of J1 to J3. Eighteen percent had best-corrected near vision of J4 or worse. Sixty-three percent of multifocal cases versus 4% of monofocal cases needed no spectacle correction. Multifocal cases reported significantly more visual side effects (flare, glare, and halos). The 10% of cases with poor satisfaction (rating vision as fair-to-poor) had significantly (P = 0.03) more postoperative astigmatism (1.1 prism diopters [D] versus 0.74 D) compared with satisfied (good-to-excellent) cases. Patients who were dissatisfied reported more need for corrective lenses but not more side effects. A greater decrease in contrast sensitivity at low contrast levels was detected among multifocal cases. Both groups had similar contrast sensitivity at 96% and 50% contrast, but at 11% contrast, multifocal cases averaged a loss of 3.45 Snellen lines (to 20/48.2) compared with 2.65 lines (to 20/36) for monofocal cases.

Implantation in Children

With the development of posterior chamber lenses and continuous curvilinear capsulorhexis, and with the availability of viscoelastic agents, the use of intraocular lenses (IOLs) in children is becoming more popular. Since 1982, we have implanted posterior chamber IOLs (PC-IOLs) in the capsular bags of 61 cataractous eyes of 46 children and adolescents. The goal was in-the-bag placement facilitated by the use of a small capsulectomy, and, since 1984, by the use of the continuous curvilinear capsulorhexis. Forty-four cataracts were congenital, 13 were traumatic, and 4 were developmental. Cataract extraction with IOL implantation was performed in 16 (26%) preschool cases (ages 2 through 5), in 31 (51%) child cases (ages 6 through 12), and 14 (23%) adolescent cases (ages 13 through 18). Surgical and postoperative complications were minimal. Visual results were good. Fifty-six percent of preschoolers, 87% of children, and 86% of adolescents achieved 20/40 or better best corrected vision, with 79% of the total cohort achieving 20/40 or better. Overall, 35% achieved an uncorrected visual acuity of 20/40 or better. All but two cases had improvement in best corrected vision; if 20/20 was not attained, the cause was mainly due to deprivation amblyopia. Forty-eight percent of patients were within a diopter of emmetropia.

Small incisions to control astigmatism during cataract surgery

ABSTRACT Astigmatic changes in three series of cataract surgical procedures were compared. Two series comprised eyes having phacoennilsification and implantation of a foldable silicone lens through a 3.0 mm to 4.0 mm incision or a 5.8 mm diameter polyinethylmethacrylate (PMMA) lens through a 6.0 min incision. The third series comprised eyes having a planned extracapsular cataract extraction (ECCE) procedure through a 10.0 min incision and implantation of a PIMA posterior chamber lens. Surgically induced cylinder changes were compared by examining preoperative and postoperative dioptric cylinder power changes without regard to axis changes and by using vector analysis to compute induced cylinder for cases with axis changes. Both phacoemulsification series had similar mean induced cylinder levels, which were significantly less than mean induced cylinder in the ECCE group at both three and six months after surgery. Over 70% of the eyes in the two small incision phacoemulsification groups achieved an uncorrected visual acuity of 20/40 or better at three months, whereas only 28% of the ECCE group achieved that acuity. We concluded that the phacoemulsification procedure induced significantly less astigmatism and provided faster visual rehabilitation than the ECCE procedure. Furthermore, the use of small diameter PMMA IOLs inserted through small incisions minimized surgically induced cylinder in a way comparable to the use of foldable silicone implants, while maintaining good visual results with fewer postoperative complications.

Piggybacking intraocular implants to correct pseudophakic refractive error

OBJECTIVE To determine the safety and efficacy of implanting a second intraocular lens (IOL) to correct pseudophakic refractive error. DESIGN Noncomparative, prospective, consecutive case series. PARTICIPANTS Eight eyes of eight normal pseudophakes and seven eyes of seven postpenetrating keratoplasty (PK) pseudophakes were included in the study. INTERVENTION A second intraocular lens (IOL) was implanted anterior to the first in each eye in the study. MAIN OUTCOME MEASURES Efficacy was determined based on the achieved refractive correction and Snellen uncorrected visual acuity measurements. Safety was determined based on loss of best-corrected visual acuity and operative and postoperative complications. RESULTS Before surgery, spherical equivalents ranged from -5.12 diopters (D) to 7.5 D, with a mean absolute deviation from emmetropia of 3.38 D (1.62). After surgery, spherical equivalents ranged from -2.75 D to 0.5 D, with a mean absolute deviation from emmetropia of 1.21 D (0.90). Before surgery, only 7% of patients had 20/40 or better uncorrected vision, whereas after surgery, 50% had that level of vision. CONCLUSIONS Implanting a second IOL is a viable option for correcting pseudophakic refractive error.

Safety and efficacy of intracameral injections of unpreserved lidocaine to reduce intraocular sensation

Purpose: To determine the safety and efficacy of intracameral injections of unpreserved lidocaine to reduce intraocular sensation. Setting: Carolina Eye Associates, Southern Pines, North Carolina, USA. Methods: In this prospective study, 100 patients having phaccemulsification under topical anesthesia were randomly assigned to receive an intracameral injection of unpreserved lidocaine (0.5 cc of a 1% unpreserved solution) or balanced salt solution. Results: Ninety‐three patients completed the study. There were no significant between‐group differences in cell density parameters or Kowa laser flare‐cell meter measurements. Seventy‐eight percent of lidocaine patients and 56% of controls reported no sensation (P = .048, Fisher’s exact test). Conclusion: Intracameral injections of unpreserved lidocaine safely and effectively reduced intraocular sensation during phacoemulsification.

Effect of posterior chamber intraocular lens design and surgical placement on postoperative outcome.

ABSTRACT Intraocular lens (IOL) design, optical configuration, and placement have potential effects on postoperative outcome. Laboratory studies have suggested that one‐piece, biconvex designs may reduce or delay posterior capsular opacification and that in‐the‐bag fixation of the posterior chamber IOL may reduce inflammation. To document the clinical significance of IOL design and placement, we conducted a randomized, prospective, clinical trial. Six hundred uncomplicated capsulorhexis and phacocmulsification patients were randomized in a three‐factor design to receive an IOL that was one‐piece or threepiece, had a biconvex, piano‐convex, or laser ridge optic, and was bagor sulcus‐fixated. Treatment differences were related to lens placement. Patients with bag‐fixated IOLs had less posterior capsular opacification, fewer YAG laser capsulotomies, a higher percentage of centered lenses, less inflammation, and fewer late posterior capsular striae than those with sulcus‐fixated IOLs. In the latter group, patients with three‐piece IOLs had fewer posterior capsular striae at three months postoperatively. All six occurrences of haptic loop distortion were in patients with three‐piece IOLs. Patients with the one‐piece design had less late inflammation than those with the three‐piece design. Fewer YAG capsulotomies were necessary at one year in patients with the biconvex design than in those with the piano‐convex or laser ridge configurations. Operative complications, endothelial cell loss, and postoperative complications were not IOL‐related.

Progressive Hyperopia in Radial Keratotomy: Long-Term Follow-Up of Diamond-Knife and Metal-Blade Series

In an earlier report, the authors demonstrated a trend toward progressive hyperopia in radial keratotomy (RK) patients examined between one and three to four years postoperatively. In those 109 cases, the surgeries were performed using a metal-blade instrument. In the following study, the metal-blade series was updated to a total of 225 procedures, and a more recent series of 300 procedures performed on 228 patients was examined in which a diamond-knife cutting instrument was used. Patients had uncorrected visual acuity determination, cycloplegic refractions with best corrected visual acuity measurements and keratometry measurements. The authors demonstrated a hyperopic shift in the distribution of postoperative spherical equivalent (SE) values across time such that higher proportions of cases in both metal-blade and diamond-knife series were at least 1.0 diopter (D) away from emmetropia at 24 and 48 months than was the case at 12 months after surgery. Regression analysis determined that none of the preoperative or surgical variables known to affect refractive outcome of RK (alone or in combination) could account for the changes in refraction seen during the course of postoperative time. In general, changes in keratometry paralleled refractive changes, but were somewhat smaller in magnitude.

Hyperopic thermokeratoplasty: Clinical evaluation

ABSTRACT A new procedure, hyperopic thermokeratoplasty (HTK), developed in the Soviet Union for the correction of hyperopia, uses controlled thermal burns of the corneal stroma with a retractable probe tip preset to penetrate the cornea at 95% depth. The coagulations are applied in a radial pattern for spherical hyperopia. Only the peripheral cornea is treated and the effect is titrated by varying the optical zone and number of rays. The thermal effect flattens the peripheral cornea and steepens the central cornea. In this report, we prospectively evaluated the refractive results of a group of 61 HTK patients. Mean preoperative spherical equivalent was 3.9 diopters (D). Mean follow‐up to date is 5.2 months, with 44% of cases evaluated at six months and 31% at one year. The initial effect of surgery (at one day) was a mean decrease in hyperopia of 6.0 D (standard error of the mean [S.E.] = 0.3 D), resulting in a mean spherical equivalent of −2.1 D (S.E. = 0.2 D). There was a steep regression of effect between one clay and two months at which point average refraction was close to emmetropia. After two months, there was a gradual but continuing regression of effect, leveling off after six months. At five to six months, 63% of cases were undercorrected by at least a diopter; at 9 to 12 months, 83% of cases were undercorrected. The overall change in spherical equivalent at each time increased as optical zone size decreased. Adjustments to the surgical prediction software (developed in the Soviet Union) to render it more suitable for U.S. eyes are underway; smaller optical zones and/or more rays will be used to obtain final stable refractive results closer to emmetropia.