Sedimentation field-flow fractionation: a method for studying particulates in cataractous lens

Journal ArticleIt is shown that the technique of sedimentation field-flow fractionation (sedimentation [sed] FFF) can be used to determine the particle content and particle size distribution of normal and cataractous lenses. A 31-year-old normal human lens, for example, showed a particle content of 1.5% by weight with diameters ranging from 0.12 micron to 0.9 micron. The urea insoluble material present in the nuclear and cortical fractions from a densely cataractous lens contained particles ranging from 0.12 micron to 1.7 micron, with average sizes of 0.83 micron and 0.82 micron respectively, for the two fractions. These numbers offer a basis for comparison; their actual values may be shifted slightly either up or down depending on the assessment of particle density. These sizes, which correspond to molecular weights of around 2 X 10(9) dalton, are larger than previously reported for lens particulates. The sed FFF method is thus seen to permit fractionation and size analysis of small amounts of lens material in times less than one hour

Microphaco update

Journal ArticleMicrophacoemulsification, or cataract surgery using ultrasound through two small stab incisions. Wound burn is now not a problem with AMO's Sovereign system plus Whitestar technology

Early experiences with microphaco

Journal ArticleMicrophaco is the separation of irrigation from aspiration that allows removal of cataracts through sub-2mm incisions. While proven intraocular lenses (IOLs) are not available at this time to take advantage of the small wounds, these wounds are advantageous from a separating irrigation standpoint which makes it a useful instrument. It is also well suited to any clinical condition where there is either a minimal anteriour chamber or pressure in a swollen capsule. With approval of good IOLs that can be inserted through these small incisions, this technique could become the dominant surgical procedure in the future

Cohort study of 27 cases of endophthalmitis at a single institution

Journal ArticlePURPOSE: To identify potential risk factors associated with post-cataract surgery bacterial endophthalmitis. SETTING: The John A. Moran Eye Center, Salt Lake City, Utah, USA. METHODS: This retrospective cohort study consisted of patients who had surgery for cataract(s) at this eye hospital. A 10% sampling of all patients operated on for cataract surgery from January 1, 1996, to December 31, 2002, were compared with all cases of postcataract surgery bacterial endophthalmitis during this same time period at this institution. The main outcome measure(s) included surgical complication, first postoperative day wound leak, incision placement and location, intraocular lens material, whether a suture was placed, antibiotic used, collagen shield use, and whether the eye was patched. RESULTS: A total of 1525 patients were in the control cohort, and there were 27 cases of endophthalmitis. In a multivariate regression analysis, the factors found to be statistically associated with endophthalmitis were (1) wound leak on the first postoperative day (odds ratio [OR] 44 +/- 42; confidence interval [CI] 6.85 to 287; P<.001); (2) capsular or zonular surgical complication (OR 17.2 +/- 14.2; CI 3.44 to 86.4; P=.001); (3) topical antibiotic started the day after surgery rather than the day of surgery (OR 13.7 +/- 12.9; CI 2.17 to 90.9; P=.005); (4) use of ciprofloxacin rather than ofloxacin topically after surgery (OR 5.3 +/- 3.6; CI 1.41 to 20.0; P=.014); (5) not patching after surgery (OR 7.1 +/- 5.6; CI 1.47 to 36.4; P=.015); and (6) not placing a collagen shield soaked in antibiotic (OR 2.7 +/- 1.3; CI 1.06 to 7.14 P=.037). CONCLUSION: In sutureless cataract surgery, surgical complications and wound leak on the first postoperative day were most strongly associated with endophthalmitis

Clinical comparison of single-piece and three-piece truncated hydrophobic acrylic intraocular lenses

Journal ArticlePURPOSE: To determine the clinical differences between three-piece (3P) and single-piece (SP) truncated hydrophobic acrylic intraocular lenses (IOL). DESIGN: Retrospective cohort clinical study. METHODS: The setting was an academic clinical practice. The patient population consisted of subjects without confounding comorbidity that could effect central vision with at least 1-year follow-up after uncomplicated surgical placement of 3P or SP IOLs in the capsular bag and at least 20/25 best-corrected postoperative vision documented. Observation procedures were as follows: logarithm of the minimal angle of resolution (LogMAR) visual acuity (uncorrected and best corrected), digital retroillumination photographs to ascertain posterior capsular opacification (PCO), anterior capsular opacification (ACO), IOL centration, and refractive stability by comparing this refraction with the early postoperative refraction. Patients completed a dysphotopsia questionnaire. Main outcome measures were as follows: LogMAR visual acuity (uncorrected and best corrected), PCO, ACO, IOL centration, refractive stability, and dysphotopsia outcomes comparing 3P and SP. RESULTS: Seventy-five patients were enrolled (36 3P and 39 SP). Corrected and uncorrected visual acuity, refractive stability, and IOL centration were similar. Single piece truncated hydrophobic acrylic intraocular lenses had more PCO (P =.013), less ACO (P =.001), less central flash looking at a peripheral light (P =.044), and less unwanted images to the side of a light source (P =.025) . CONCLUSIONS: Although similar in centration and refractive stability, SP has more PCO, less ACO, and less dysphotopsia than 3P

Update on a long-term, prospective study of capsulotomy and retinal detachment rates after cataract surgery

Journal ArticlePURPOSE: To evaluate the retinal detachment risks and neodymium:YAG (Nd:YAG) capsulotomy rates associated with different cataract approaches and intraocular lens (IOL) styles in a long-term,prospective clinical study. SETTING: Clinical practice of 1 ophthalmologist, Fort Collins, Colorado, USA. METHODS: Prospectively studied were surgical approach, date, and complications; IOL type; axial length; patient age and sex; Nd:YAG capsulotomy and date; and retinal detachment and date. RESULTS: Phacoemulsification had a lower risk of retinal detachment than intracapsular cataract extraction (ICCE) (0.4% versus 5.4%; P <.001) and extracapsular cataract extraction (ECCE) (0.4% versus 1.6%; P =. 002). Although retinal detachment was significantly associated with Nd:YAG for ECCE (3.1% versus 1.0%; P =.01), no patient in the phacoemulsification group had a retinal detachment after an Nd:YAG treatment. Retinal detachment was strongly associated with axial length of 24.0 mm and greater (P <.001), age of 60 years or less if axial length was 24.0 mm or greater (for ECCE, P =.001; for phacoemulsification, P =.01) and sex; that is, male (for ECCE, P =. 04; for phacoemulsification, P =.02). Regarding IOL styles the Surgidev B20/20 (P <.001) and AcrySof MA60 (P <.001) had significantly lower Nd:YAG rates, while the Cilco UPB 320 GS had a significantly higher Nd:YAG rate (P <.001). CONCLUSIONS: Cataract surgical approach and IOL style significantly affect Nd:YAG and retinal detachment rates. Being a man, being 60 years or younger, and especially having an axial length of 24.0 mm or greater were associated with detachment. Some Nd:YAG approaches may not put the patient at increased risk for retinal detachment

Glistenings with long-term follow-up of the Surgidev B20/20 polymethylmethacrylate intraocular lens

Journal ArticlePURPOSE: To compare patient satisfaction with vision 12 months after implantation of a silicone or acrylic foldable intraocular lens (IOL). SETTING: John A. Moran Eye Center, University of Utah Medical Center, Salt Lake City, Utah, USA. METHODS: Selection criteria included patients who had uneventful cataract extraction by phacoemulsification with a temporal clear corneal incision or superior scleral tunnel incision, a curvilinear capsulorhexis, and in-the-bag IOL placement. One hundred sixty-two patients surveyed had a mean follow-up of approximately 15 months (range 12 to 18 months). Patients were divided into 3 groups of 54 each based on IOL type: AMO SI-30/40, Alcon MA30BA, and Alcon MA60BA. All patients were surveyed over the telephone using a standardized questionnaire protocol. They were questioned about their perception of vision with best optical correction in relation to visual blurring symptoms, glare symptoms, night vision, near vision, and overall vision. RESULTS: There were no significant differences in patient satisfaction among the 3 IOL groups in visual blurring or night vision. Patients in the SI-30/40 and MA60BA groups reported significantly higher satisfaction with glare symptoms, near vision, and overall satisfaction than patients in the MA30BA group. CONCLUSION: The SI-30/SI-40 and the MA60BA IOLs received significantly higher patient satisfaction scores than the MA30BA IOL in glare symptoms, near vision, and overall satisfaction

Legacy AdvanTec and Sovereign WhiteStar: a wound temperature study

Journal ArticlePURPOSE: To assess the wound temperature of the Sovereign WhiteStar (S-WS) (AMO) and Legacy AdvanTec (L-ADV) (Alcon) phacoemulsification systems. SETTING: John A. Moran Eye Center, Health Sciences Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Phacoemulsification using 20-gauge, 30-degree straight tips with the L-ADV and S-WS systems was performed in fresh cadaver eyes. The power was set at 50%, and aspiration was 12 mL/min; the L-ADV was run at 15 pulses per second (pps) and the S-WS at WS CF (6 milliseconds on, 12 milliseconds off). Temperature was measured at 5-second intervals for 60 seconds using a microthermistor placed in the wound. The phaco tip was angled 30 degrees to increase wound-tissue contact. At 10 seconds, the flow was clamped to simulate occlusion. Five runs, sleeved and unsleeved, were averaged for the phaco tip. RESULTS: The mean temperature was significantly higher with L-ADV than with S-WS (from 10 seconds on in the sleeved condition and from 5 seconds on in the unsleeved condition after the aspiration line was clamped). In 2 of 5 sleeved runs and 4 of 5 unsleeved runs, the L-ADV handpiece decreased power as the temperature increased. One run with the L-ADV with sleeve showed signs of wound burn. There were no signs of wound burn with the S-WS. The highest temperature recorded was 57.5 degrees C with the L-ADV and 38.6 degrees C with the S-WS. Power tests showed L-ADV protected the stroke length and S-WS had constant power except in air where it increased power. CONCLUSIONS: There was less increase in wound temperature over time with the S-WS than with the L-ADV system in sleeved and unsleeved simulated surgery in human eye-bank eyes. Because the ultrasound handpieces respond differently under different load scenarios, meaningful comparisons of pulsing features are difficult to creat

Penetrating keratoplasty for keratoconus: a long-term review of results and complications

Journal ArticlePURPOSE: To study the long-term complications of penetrating keratoplasty (PKP) to evaluate current recommendations to patients with keratoconus. SETTING: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Retrospective study of all PKP procedures for keratoconus performed by 4 surgeons during a 312 year period. Follow-up was 1 day and 1, 3, 6, 12, and 24 months post-PKP. Data from 93 eyes were reviewed for allograft reaction, astigmatism, visual acuity, reasons for decreased visual acuity, and other complications. RESULTS: Allograft reaction was seen in 31% of cases but no graft failure due to allograft reaction. Mean astigmatism was 2.76 diopters (D) +/- 1.99 (SD) at 24 months, with only 15% > 5.00 D. Last best corrected visual acuity was 20/25 or better in 77% of cases (87% had 20/25 or better at some time during follow-up). Complications that did not cause decreased visual acuity were noted. Punctate keratitis was noted in 20% of patients 180 days or more after surgery. CONCLUSIONS: Penetrating keratoplasty is a good treatment option for patients with keratoconus but should be reserved for those who do not tolerate contact lenses or do not get needed visual acuity with contact lenses because of complications. This procedure has become a second-line treatment for keratoconus patients and has generally good results

Efficacy and wound-temperature gradient of WhiteStar technology phacoemulsification through a 1.2 mm incision

Journal ArticlePURPOSE: To evaluate the efficacy and wound-temperature gradients of WhiteStar micropulse technology using bimanual phacoemulsification without an irrigation sleeve through a 1.2 mm incision. SETTING: Island Eye Surgicenter, Carle Place, New York, USA. METHODS: Ten patients had bimanual phacoemulsification using micropulse technology without an irrigation sleeve through a 1.2 mm clear corneal incision. A thermocouple consisting of a 30-gauge copper wire was inserted into clear cornea directly adjacent to the wound to digitally record temperature gradients at the wound. Endothelial cell counts were evaluated preoperatively and postoperatively in all patients. RESULTS: All 10 patients maintained corneal clarity with no sign of thermal damage to the wound. The maximum corneal wound temperatures during phacoemulsification ranged from 24 degrees C to 34 degrees C, well below the temperature of collagen shrinkage. The endothelial cell loss at 3 months was 7%. CONCLUSIONS: Because of the decreased thermal effect with WhiteStar technology, an irrigation sleeve over the phacoemulsification needle is superfluous. As a result, bimanual phacoemulsification can be safely performed through a 1.2 mm incision