Journal - American Intra-Ocular Implant Society最新文献

We report on 216 cases of posterior capsulotomy performed with a LASAG Microruptor II YAG laser in patients with posterior chamber intraocular lenses. In 108 cases, the YAG laser was used in multimode with a 70-micron spot and 3.5 mJ to 5.0 mJ of energy; in the other 108 cases, the laser was used in fundamental mode with a 7-micron spot and 0.7 mJ to 1.2 mJ of energy. In the first group, IOL damage was seen in 10.2% of cases, uveitis developed in 0.4% of patients, and transient eye pressure elevation was noted in 6.5% of patients.In the second group, neither IOL damage nor uveitis occurred, and only two cases (1.8%) developed transient pressure elevation.

A sterile corneal ulcer was observed in four cataract patients (two with intraocular lenses) during the early postoperative period. All patients had a history of rheumatoid arthritis and were on systemic antiinflammatory agents. The two patients treated medically exhibited a short recovery phase with complete healing over several days and no recurrence. Aggressive treatment of the dry eye syndrome with artificial tears, bandage lenses, punctal occlusion, tarsorrhaphy, and antibiotics resulted in immediate improvement. In this report, variabilities in corneal ulceration are stressed while emphasis is given to the role of dry eyes and exposure as the principal common factor. A discussion of risk factors, presentation, treatment, pathogenesis, and prevention is provided.

Corneal alterations from hard contact lens wear can have significant effects on the results of intraocular lens (IOL) calculation and this should be kept in mind in those patients who are candidates for lens implantation. Seven patients were studied during and two weeks after hard contact lens wear, showing an average increase of +0.79±1.05 (P < 0.05) in keratometry reading and an average decrease of -0.98 in emmetropic IOL calculations after discontinuing contact lens wear. Since the effect of hard contact lens wear on corneal curvature and resultant IOL calculations is variable and unpredictable, it is important that IOL calculations be made well after discontinuation of hard contact lens wear.

Forty-one diabetic patients who had modified J-loop lenses with ten-degree angulation implanted in the ciliary sulcus and 58 diabetic patients who had the same style lenses implanted in the capsular bag had posterior capsulotomy performed on the table or later at predetermined intervals. The operation was performed with a cystotome needle or with the Nd:YAG laser on the first postoperative day or later. The study indicates that the development of new or the worsening of old diabetic iris and retinal changes, as well as cystoid macular edema, were much less if (1) the intraocular lens was implanted in the capsular bag, (2) at least nine months elapsed between cataract surgery and capsule interruption, and (3) topical indomethacin and topical steroid treatment was given preoperatively and postoperatively. There was little difference in diabetic progression between cystotome needle and YAG laser posterior capsulotomy.

For surgeons who do not have a Nd:YAG laser, we describe the use of a 25-gauge disposable hypodermic needle for removing undesirable tissue from an intraocular lens surface to obtain a clear view of the vitreous and retina in the complicated pseudophakic eye.

A comparison of intraocular lens damage associated with four different Nd:YAG laser instruments was performed using polarized light, scanning electron microscopy, and a qualitative measurement of optical resolution. Five intraocular lens designs, each of which provided a different separation between the intraocular lens and a model of the posterior capsule, were tested with each laser instrument. There was no statistically significant difference in the frequency of lens pitting caused by each laser. Intraocular lenses designed with a theoretical separation of 0.25 mm or more between the lens and the posterior capsule sustained no damage with any of the laser instruments used in this study.

Use of the Nd:YAG laser is an effective technique to open an opacified posterior lens capsule. However, in the presence of a posterior chamber intraocular lens (IOL), precise focusing of the laser on the capsule is required to avoid pitting the lens optic. The question has been raised whether toxic products may result from laser damage to the IOL. We addressed this issue in the present study by exposing primary human corneal endothelial cell and human corneal organ cultures to solutions produced by purposefully hitting IOLs immersed in cell growth medium with a Nd:YAG laser. The lenses studied were lathe-cut polymethylmethacrylate (PMMA), injection-molded non-UV PMMA, injection-molded UV PMMA, and. cast-molded UV PMMA. Samples of each material were irradiated in a holder containing 1 ml of cell culture medium using the following conditions: 5, 10, and 50 laser bursts at 10 millijoules (mJ), and 50 laser bursts at 5 mJ. The solutions were applied to the endothelial cell cultures (all materials) and to the corneal organ cultures (injection-molded non-UV lenses only). There was no toxicity in either assay for any of the materials studied.