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.

Multifocal intraocular lenses.

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.

Intraocular histiocytic lymphoma: a pediatric case presentation.

An 11-year-old white female with a 5-month history of stage IV systemic histiocytic lymphoma presented in relapse with a red, painful left eye with a decrease in visual acuity. A diagnostic anterior chamber paracentesis was performed revealing cells consistent with the systemic diagnosis of histiocytic lymphoma. Also, at that time, central nervous system involvement was found. This is the youngest patient to our knowledge to have documented intraocular involvement from histiocytic lymphoma. She is also unusual in that the ocular involvement was predominantly localized to the anterior segment.

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.

Intraocular lens implantation in phakic rabbit eyes.

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 eye 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.

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.

Paired arcuate keratotomy. A surgical approach to mixed and myopic astigmatism.

Twenty-five cadaver eyes were used to study the effect of paired arcuate keratotomy on corneal astigmatic changes. Paired arcuate incisions placed at optical zones of 5, 6, 7, 8, and 9 mm were progressively lengthened from 45 degrees to 60 degrees, 90 degrees, and, finally, 120 degrees. The corneal flattening in the meridian centered over the incisions and the corneal steepening 90 degrees away were quantified with each successive lengthening. Linear regression analysis showed a direct linear relationship of corneal astigmatic change (sum of corneal flattening and steepening, or delta K) to decreasing optical zone size as measured in millimeters and increasing incision length as measured in degrees. The delta K value ranged from 2.65 +/- 1.07 diopters to 22.05 +/- 3.55 D. The flattening/steepening coupling ratio mean was 1.47 +/- 0.41. Progressively longer paired arcuate incisions produced a predictable and titratable corneal flattening in the meridian centered over the incisions and a slightly smaller corneal steepening 90 degrees away, making the procedure ideal for mixed astigmatism.

The ocular manifestations of Rocky Mountain spotted fever.

To our knowledge, this is the first report of an iris nodule in a case of Rocky Mountain spotted fever (RMSF). The iris nodule may be similar to the "typhus nodule" of the central nervous system reported at autopsy in patients with typhus rickettsial disease. Previous case reports of RMSF have emphasized either anterior uveitis or retinal vasculitis. In the case reported here, both occurred in our patient as a result of RMSF. Also, we review the ophthalmic literature on rickettsial disease.

Calcium deposition in a corneal graft.

Corneal calcification can be broken down into two distinctly different types: calcific band keratopathy and calcareous corneal degeneration. Both have been described in patients with ocular inflammatory disorders, with elevated serum calcium, or following ocular surgical procedures. This is the first case report of corneal calcification in a donor corneal button following penetrating keratoplasty, and it closely resembled calcareous corneal degeneration.