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Biomedical subjects

Michael D Olson

Publications and source records attributed to Michael D Olson.

8 recordsLinked to original sources
PubMed2006

Implanting a clear intraocular lens in one eye and a yellow lens in the other eye: a case series.

PURPOSE: To describe the color vision disturbance reported by patients in whom a clear intraocular lens (IOL) was implanted in one eye and a yellow-tinted (blue-light-absorbing) IOL in the other eye. DESIGN: Retrospective interventional case series. METHODS: Data recorded included demographic information, dates of surgery, IOL model and power (manufacturer is the same for all lenses), best-corrected visual acuity, and subjective visual complaints. RESULTS: Four of five patients had no spontaneous color vision complaints. When these patients were informed of the unintended mismatch, all remarked that they could perceive a color vision difference, but that it was not bothersome. One of the five patients reported "beige" vision. None of the patients wanted an IOL exchange. CONCLUSION: Many patients can tolerate the color vision imbalance that results when a clear IOL is implanted in one eye and a yellow-tinted IOL is implanted in the other eye.

Aged↗
PubMed2005

In-air thermal imaging comparison of Legacy AdvanTec, Millennium, and Sovereign WhiteStar phacoemulsification systems.

PURPOSE: To compare the temperature profiles of 3 popular phacoemulsification units (Alcon Legacy AdvanTec, Bausch & Lomb Millennium, and AMO Sovereign WhiteStar) under similar operating conditions in air. SETTING: Jules Stein Eye Institute and the Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. METHODS: Phacoemulsification probes from the 3 units were placed side by side in air and imaged in the infrared region using model P60 ThermaCAM (Flir Systems). The highest temperature produced by each probe was measured 10 seconds and 30 seconds after power application. Testing was performed under conditions that might produce a corneal burn during cataract surgery. Irrigation flow was set at the low rate of 1 cc/min to simulate a tight incision. Aspiration flow was set at 0 cc/min to simulate occlusion of the needle lumen. Wound compression was simulated in some tests by suspending 22.6 g weights by rubber bands from the silicone sleeves. Manufacturers' specific and identical silicone sleeves were used to evaluate possible variations in thermal conductivity. The AdvanTec Legacy and Millennium were operated in pulse mode at 15 Hertz; 50% duty cycle; and 10%, 30%, and 50% power. The Sovereign WhiteStar was operated in both C/F (56 Hz, 33% duty cycle) and C/L (33 Hz, 20% duty cycle) modes at the same console power settings. Temperature profiles were determined at a variety of power settings with each system operating in continuous and pulse mode. RESULTS: Under all experimental conditions (at 10%, 30%, and 50% powers; with and without external weights suspended from the phacoemulsification probes; with manufacturers' and identical silicone sleeves; and in continuous and pulse modes), the Millennium and the Sovereign WhiteStar generated higher temperatures than the Legacy AdvanTec. CONCLUSIONS: Under controlled operating conditions in air and under a variety of power, load, and duty-cycle settings, the Millennium and the Sovereign WhiteStar, operating in both pulse and continuous modes, generated higher peak temperatures than the Legacy AdvanTec.

Air↗
PubMed2005

Pillow case.

An 80-year-old man with severe kyphosis and visually significant cataracts in both eyes came to us for care. He had been scheduled for cataract surgery elsewhere, but his surgery was cancelled in the operating room when he could not be positioned adequately beneath the operating microscope. As he sat in a chair in our examining room, he was only able to elevate his head to a position 30 degrees below the horizontal. His cataract surgery was performed safely and effectively by padding the operating table with 14 pillows. Eleven pillows were placed under his buttocks and legs and 3 pillows beneath his head and neck. The operating table was also positioned in maximum reverse Trendelenburg to obtain a good red reflex.

Aged, 80 and over↗
PubMed2004

Reasons patients recommend laser in situ keratomileusis.

PURPOSE: To evaluate the reasons patients who have had laser in situ keratomileusis (LASIK) recommend it to others and examine the disparity between high levels of satisfaction and patient reports of night-vision symptoms and/or dry eye after LASIK. SETTING: Northeastern Eye Institute, Scranton, and the University of Pittsburgh, Pittsburgh, Pennsylvania, and the University of California at Los Angeles, Los Angeles, California, USA. METHODS: Questionnaires assessing symptoms and satisfaction after LASIK were mailed to 2,100 patients. The questionnaires included items about night-vision symptoms and satisfaction and an open-ended question for patients to give their reasons for recommending LASIK to others. The open-ended responses were categorized and tabulated. RESULTS: Four hundred thirty-four patients provided reasons for recommending LASIK to others. Sixteen categories of reasons were identified. "No more spectacles/contact lenses" was listed by 180 patients (42%), followed by "better vision" (21%) and "convenience" (15%). Women were significantly more likely to cite "better comfort" (27 women versus 3 men; chi square = 8.99, P =.003) and "better quality of life" (41 women versus 9 men; chi square = 7.36, P =.007) as a reason for recommending LASIK. Of the 35 patients who reported dissatisfaction with post-LASIK vision, 20 (57%) would recommend LASIK to a friend because "LASIK helps others." CONCLUSIONS: Categories of reasons for recommending LASIK to others were similar to reasons given by patients for seeking LASIK. Some patients who reported dissatisfaction with their vision said they would recommend LASIK, suggesting that recommendation of LASIK to others is not necessarily a measurement of the quality of a patient's vision after LASIK.

Adult↗
PubMed2004

Ophtec iris reconstruction lens United States clinical trial phase I.

PURPOSE: To determine the safety and efficacy of the Ophtec model 311 iris reconstruction lens for treatment of visual disturbances, such as glare or photophobia, related to partial or total absence of the human iris. DESIGN: Phase I multicenter, nonrandomized, investigational device study. PARTICIPANTS: Ten iris reconstruction lenses were placed in 10 subjects at 6 sites. METHODS: Iris reconstruction lenses were placed in 9 patients who had lost all or part of their iris from trauma and in 1 patient who lacked iris pigmentation due to congenital albinism. Patients were examined preoperatively, intraoperatively, and postoperatively at day 1; week 1; and months 1, 3, 6, and 12. MAIN OUTCOME MEASURES: Efficacy measures were uncorrected visual acuity (UCVA), glare, starbursts, and photophobia. Safety measures were best-corrected visual acuity (VA), surgical complications, and adverse events. RESULTS: Uncorrected VA improved in all eyes after implantation of the iris reconstruction lens. Best-corrected VA did not change significantly (P = 0.24). Postoperative photophobia was reduced in all 9 eyes that experienced moderate to severe preoperative photophobia. Likewise, postoperative glare was reduced in all 6 eyes with moderate to severe preoperative glare. There were no surgical complications. Adverse events included 2 cases of iritis and 1 case of macular edema. CONCLUSIONS: Preliminary results suggest that the Ophtec model 311 iris reconstruction lens can improve UCVA and reduce glare and photophobia in patients with partial or total absence of the iris or iris pigmentation.

Adult↗
PubMed2004

The effect of LASIK on best-corrected high-and low-contrast visual acuity.

PURPOSE: To evaluate the effects of laser in situ keratomileusis (LASIK) and LASIK with concurrent astigmatic keratectomy (LASIK/AK) on high- and low-contrast visual acuity. METHODS: The setting was a university refractive surgery practice. Patients were recruited from those undergoing LASIK or LASIK/AK for myopia (>1.00 D spherical equivalent) between May 1996 and August 1997. All subjects were at least 21 years of age. Testing occurred preoperatively and 3 and 6 months after LASIK. Main outcome measures were best spectacle-corrected, high- and low-contrast visual acuity. RESULTS: For all subjects, there was a significant effect of surgery on nondilated low-contrast visual acuity (repeated measures two-way analysis of variance, p < 0.0001). Tukey's posthoc analysis showed that preoperative low-contrast visual acuity scores were significantly different from 3-month [0.08 logarithm of the minimum angle of resolution (logMAR)] and 6-month (0.11 logMAR) scores for patients undergoing LASIK and LASIK/AK. Under dilated conditions, there was a significant effect of surgery for high- and low-contrast visual acuity (analysis of variance, p < 0.0001 for both). Only changes in low-contrast visual acuity were clinically meaningful [LASIK, visual acuity reduction of 0.1 logMAR (1 line); LASIK/AK, visual acuity reduction of 0.15 logMAR (1.5 lines)]. When considering high and low myopes separately (LASIK only), the level of myopia had a significant effect on the visual acuity after surgery (analysis of variance, p = 0.01). Preoperative, dilated, low-contrast visual acuity scores for high myopes were significantly different from 3-month (0.14 logMAR) and 6-month (0.13 logMAR) scores. No differences were noted for low myopes. CONCLUSIONS: Clinically meaningful postoperative changes in low-contrast visual acuity were noted in patients undergoing LASIK and LASIK/AK under natural and dilated conditions. Postoperative, dilated, low-contrast visual acuity scores were significantly worse than preoperative scores for high myopes, but remained unchanged for low myopes.

Adult↗
PubMed2002

Complexity of contact lens fitting after refractive surgery.

PURPOSE: To quantify and describe the complexity of contact lens correction on corneas altered by refractive surgery. DESIGN: A case-control study involving postrefractive surgery patients and controls from one multidisciplinary contact lens practice. METHODS: The contact lens care of one randomly selected eye of 30 postrefractive surgery patients (15 postincisional and 15 postlamellar refractive surgery cases) was retrospectively analyzed and compared with that of 30 age-and-gender matched nonrefractive surgery controls. We quantified the complexity by the number of diagnostic lenses used to establish the initial lens order, the number of ordered lenses required to complete the fit, and the number of office visits during the first 4 months of lens care. Final contact lens optical powers, corrected visual acuities, complications, and lens success/failure were also studied. The nonparametric Mann-Whitney U test was used for statistical analysis. RESULTS: Postrefractive surgery eyes utilized statistically more diagnostic lenses (P =.048), ordered lenses (P =.008), and office visits (P <.0001). There were no statistical differences in the number of office visits, number of diagnostic contact lenses used, and number of ordered contact lenses between the postincisional and postlamellar refractive surgery patients. Although final contact lens optical powers were not significantly different (P =.06) between the two groups, contact lens corrected LogMAR acuities were statistically worse (P =.013) in the postrefractive surgery eyes than in the control group. Contact lens failures occurred in four postrefractive surgery eyes, while no eyes in the control group failed to tolerate contact lenses. CONCLUSIONS: Corneas altered by either incisional or lamellar refractive surgery techniques are more challenging to fit with contact lenses than nonsurgically altered eyes, requiring more lenses and chair time, while resulting in slightly poorer contact lens corrected visions and more failures.

Adult↗