Richard J. Duffey

Anatomic Study of Transsclerally Sutured Intraocular Lens Implantation

We used 21 cadaver eyes to study transsclerally sutured, ciliary sulcus-fixated intraocular lens implantation. Results showed that transscleral sutures should exit the sclera less than 1 mm posterior to the corneoscleral limbus for true ciliary sulcus fixation. The relationship of the ciliary sulcus to the overlying posterior surgical limbus differed in the vertical and horizontal meridians; needles that pierced the ciliary sulcus after being passed perpendicularly through the sclera entered the sclera 0.83 +/- 0.1 mm posterior to the posterior surgical limbus in the vertical meridians and 0.46 +/- 0.1 mm in the horizontal meridians. The major arterial circle of the iris (located in the ciliary body) was avoided as was the entire ciliary body during proper ciliary sulcus fixation. A one-piece, all polymethylmethacrylate, 10-degree vaulted, 13.5-mm haptic spread intraocular lens provides excellent optic centration and haptic stabilization when the haptic structure is placed at the greatest haptic spread and one transscleral suture pass per haptic is made.

US trends in refractive surgery : 2002 ISRS survey

PURPOSE To determine the latest trends in refractive surgery in the United States. METHODS The full U.S. membership of the International Society of Refractive Surgery (ISRS) (approximately 900 members) was mailed the 2002 refractive surgery survey dealing with volumes, types, preferences of refractive surgery performed, and use of emerging technology. RESULTS Questions regarding RK, AK, PRK, LASIK, LASEK, intracorneal ring segments (ICRS), laser thermal keratoplasty (LTK), conductive keratoplasty (CK), phakic intraocular lenses (PIOL), and clear lens extractions (CLE) were examined in the survey. Procedure preference for low, moderate, and high myopia, and hyperopia, were compared with the results from the surveys of the previous 5 years. Preference for unilateral versus bilateral same-day surgery, laser type, and microkeratome choice were also compared with the survey data from previous years. Incidence and frequency of co-management of refractive surgery patients were compared with 1999-2001 data. New questions regarding pupil measurement/documentation, wavefront aberrometry, and custom ablations were incorporated into the 2002 survey. CONCLUSIONS As refractive surgery grows in the mainstream of ophthalmology, trends and changes in the United States continue to be elucidated by this professional organization survey. LASIK continues to dominate for refractive errors between -10.00 to +3.00 D. LASIK, LASEK, CLE, PIOL, and CK appear to have bright futures, whereas, RK, ICR, and LTK are on the decline. VISX continues to be utilized 2:1 over all other lasers combined, and instrumentation pupillometry is preferred 2:1 over pupil gauge cards. Currently, wavefront aberrometry and custom ablations are minimally employed but appear poised to be the wave of the future.

Multifocal intraocular lenses

ABSTRACT Current multifocal intraocular lens designs incorporate refractive or diffractive optical principles to achieve increased depth of focus. Information about four basic design concepts is presented. Early clinical results with two of these, the IOLAB Nuvue two‐zone refractive multifocal and the 3M diffractive multifocal, are summarized.

Thin flap laser in situ keratomileusis: Flap dimensions with the Moria LSK-One manual microkeratome using the 100-μm head

Purpose: To determine the predictability and consistency of corneal flap thickness, flap diameter, and hinge length with the modern 100 μm head of the Moria LSK‐One manual microkeratome. Setting: Private clinic, office‐based practice. Methods: Forty‐two consecutive eyes with no previous surgery having thin flap laser in situ keratomileusis with the Moria LSK‐One manual microkeratome had a new 100 μm (predicted flap thickness) head used for flap creation. Flap thickness was measured intraoperatively by subtraction ultrasound pachymetry (difference between central corneal thickness before flap cutting and residual stromal bed thickness after flap lifting). Vertical flap diameter and nasal hinge length were measured with calipers. Results: Mean flap thickness was 107 μm ± 14 (SD) (range 82 to 137 μm). Standard deviation for mean vertical flap diameter was ±0.24 mm. The cord length of the nasal hinge was variable with a mean of 4.26 ± 0.63 mm (range 3.12 to 5.75 mm) in length. Postoperatively, there were no slipped flaps, flap striae, diffuse lamellar keratitis, or epithelial defects; there was 1 epithelial slide. At 1 day, the visual acuity was 20/20 or better in 76% of eyes. Conclusions: The 100 μm head of the Moria LSK‐One manual microkeratome cut a very predictable flap thickness and diameter but with variable length hinges. This flap thickness predictability was superior to that in other series with thicker intended flaps cut with mechanical microkeratomes and is comparable to that reported with the IntraLase FS femtosecond laser. Visual recovery was rapid, epithelial risks minimal, efficiency superior, and cost nominal relative to femtosecond laser technology.

Human cadaver corneal thinning for experimental refractive surgery.

Human cadaver eyes can be dehydrated by prolonged elevation of intraocular pressure (three to five hours) or by hyperosmotic Dextran over a 20- to 30-minute period. We divided four pairs of donor eyes into two groups (A and B) and dehydrated four corneas by each method. After corneal thinning to 500 to 600 microns, central corneal pachymetry was measured every ten minutes during the rehydration period for one hour, with each cornea pair being moistened at a different rate (every 30 seconds, 1 minute, 2.5 minutes or 5 minutes). The resultant increase in central corneal thickness noted by change in pachymetry (delta P) ranged from 12.4% to 14.7% over one hour between the two groups. delta P did not differ significantly between groups A and B, regardless of the varying rate of balanced salt solution irrigation of the corneas. Thus, it appears that either method of corneal dehydration provides comparable stability of corneal thinning for at least one hour to allow consistent corneal dynamics for experimental refractive surgery.

U.S. Trends in Refractive Surgery: 2001 International Society of Refractive Surgery Survey

PURPOSE To determine the trends in refractive surgery in the United States in 2001. METHODS The 980 U.S. members of the International Society of Refractive Surgery were mailed the 2001 refractive surgery survey dealing with volumes, types, and preferences of refractive surgery performed. Questions regarding radial keratotomy, astigmatic keratotomy, photorefractive keratectomy, laser in situ keratomileusis (LASIK), laser subepithelial keratomileusis, intracorneal rings (Intacs), laser thermal keratoplasty, conductive keratoplasty, clear lens extraction, phakic intraocular lenses, and scleral expansion procedures for presbyopia were examined in the survey. Procedure preferences for low, moderate, and high myopia and hyperopia were compared with the results from the surveys of the previous 4 years. Preference for unilateral versus bilateral same-day surgery, laser type, and microkeratome choice were also compared with the survey data from previous years. Incidence and frequency of comanagement of refractive surgery patients were compared with 2000 data. RESULTS AND CONCLUSION LASIK remains the dominant refractive surgery for refractive errors from -12.00 to +3.00 D; the VISX excimer laser and the Hansatome microkeratome are the most frequently used instruments for LASIK.

Bilateral Serratia marcescens Keratitis After Simultaneous Bilateral Radial Keratotomy

PURPOSE/METHODS After bilateral simultaneous radial keratotomy, Serratia marcescens keratitis, which involved multiple incisions of both eyes, developed in a 46-year-old physician. The keratitis was treated with repeated wound debridement, fortified topical antibiotics, and topical povidone-iodine. RESULTS/CONCLUSIONS Six months after radial keratotomy, uncorrected visual acuity was R.E.: 20/25 and L.E.: 20/60, both eyes correctable to 20/20. Health-care workers who undergo refractive surgery may be at increased risk of acquired postoperative infections because of their work environment. Although the occurrence of simultaneous bilateral ulcerative keratitis after simultaneous bilateral radial keratotomy is rare, it is nonetheless a real possibility, making it prudent to perform radial keratotomy on one eye at a time.

Intraocular lens implantation in phakic rabbit eyes

ABSTRACT Three sizes (13.5 mm, 17.5 mm, and 18.5 mm) of open loop, one piece, poly(methyl methacrylate) anterior chamber intraocular lenses (IOLs) were implanted in 12 phakic rabbit eyes to evaluate the effect of the IOL on the crystalline lens and the anterior chamber. Six eyes were used as a control group. Minimum follow‐up was four weeks. All the IOLs touched the crystalline lenses, and on the first postoperative day, round subcapsular lens opacities were found in all eyes in the area of IOL contact. The lens opacities became more dense with time. Only one eve in the control group showed a subcapsular opacity, which was linear rather than round. Anterior chamber inflammation was 1 + to 2 + in ten eyes (80%) in the IOL group during the first and second weeks, whereas minimal inflammatory changes occurred in the control group. These results suggest that with current IOL technology, IOL insertion in the phakic eye to correct refractive errors results in a high incidence of cataract if IOL‐to‐lens touch occurs.