In vivo lens density measurements using the IntraOptics opacity lensmeter.

We evaluated 589 eyes using the IntraOptics opacity lensmeter 701. Twenty-one eyes contained poly(methyl methacrylate) intraocular lenses. The patients in the phakic group (578 eyes), who had no ocular pathology other than refractive error or cataracts, averaged 60.3 years of age, had an average visual acuity of 20/30, and displayed an average lens density as measured with the opacity lensmeter of 22.09. The data were analyzed for the effect of age upon density using various regression models. The best fit was obtained with an exponential model: Density = 6.2 x e(0.02 x Age), with a correlation coefficient of 0.759. The average density for the pseudophakic group (mean age = 68.5) was 9.23. Neither cortical nor posterior subcapsular cataracts were well recorded. Our results indicate that the IntraOptics opacity lensmeter is a rapid and accurate instrument for documenting nuclear cataract changes. The opacity lensmeter may prove useful not only as a clinical tool for monitoring cataract progression but also as an "electronic" second opinion.

Comparison of the keratometer and the lens bench in measuring intraocular lens power.

Intraocular lenses (IOLs) from six manufacturers were measured on a Terry keratometer and on a calibrated lens bench for lens power. Differences between the two methods appeared when the IOLs were a different refractive index than polymethylmethacrylate (PMMA) and a shape other than planoconvex. These differences were consistent for ultraviolet absorbing PMMA and for meniscus lenses.

In vivo fracture of an extruded polymethylmethacrylate intraocular lens loop.

The inferior loop of a semiflexible, closed-loop anterior chamber intraocular lens in the eye of a 72-year-old female fractured at two sites. The loop was composed of extruded polymethylmethacrylate. The inferotemporal portion of the loop was first noted to be broken 25 months postoperatively, and the fractured nasal portion of the same loop was first observed 55 months after implantation. The patient denied any excessive rubbing of the eye or major trauma to the eye or head. Both fractures occurred near the loop-optic junction. The intermittent touch of the cornea by the broken loop caused endothelial damage and edema in the lower one third of the cornea. The two portions of the lens were removed and exchanged with another style of anterior chamber lens. The visual acuity at six weeks postexchange was 20/30.

Iris transillumination defect and microhyphema syndrome.

We present a previously undescribed delayed complication attributable to sulcus-fixated posterior chamber lenses with elliptical polypropylene haptics containing a 10 degrees anterior angulation. Clinical signs of this complication are crescent-shaped iris transillumination defects overlying the lens haptics in the peripheral iris; in some cases these are associated with single or recurrent visually significant microhyphemas. This series describes 41 eyes that contain these transillumination defects; eight of the eyes have had lens-induced intraocular hemorrhage. We estimate the overall incidence of transillumination defects in our sulcus-fixated posterior chamber lens patient population to be between 5% and 15%. Those patients who have had lens-induced hemorrhage represent slightly greater than 1%, which is higher than our incidence of cystoid macular edema or retinal detachment. It is important for all ophthalmologists to be aware of this syndrome in evaluating patients with posterior chamber lenses who present with a transient obscuration of vision.

Clinical experience with the Nd:YAG laser.

This study presents the results and complications of 389 patients who were treated with the Nd:YAG laser between September 1982 and November 1983 with at least a six-month follow-up. The majority of patients had a secondary discission of the posterior capsule. Other procedures included vitreolysis, iridotomy, pupilloplasty, synechialysis, intraocular suture cutting, cutting of intraocular lens haptics, and removal of anterior pseudophakic pigmented precipitates. We have purposely avoided performing preoperative laser anterior capsulotomies and have been unsuccessful in reopening freshly sealed trabeculectomy sites. The visual acuity improved in 83.1% of patients. No statistically significant difference in visual outcome was detected in relation to the time interval between surgery and Nd:YAG laser treatment. The most common adverse finding was an increase in intraocular pressure, which occurred to some degree in 63% of patients. Rare complications included cystoid macular edema and retinal detachment. No statistical correlation between these complications and preexisting conditions or intraoperative variables could be found.

Technique for implanting secondary posterior chamber intraocular lenses.

This paper describes a surgical technique for implanting a secondary posterior chamber intraocular lens (IOL). Endothelial cell counts in a small series of patients are also discussed.

The Shearing intraocular lens: a report of 1,000 cases.

Implantation of Shearing and Shearing-style J-loop posterior chamber lenses in 1000 cases was associated with an absence of corneal decompensation and a low incidence of glaucoma, cystoid macular edema, iritis, vitritis and retinal detachment. The low complication rate was attributed to the posterior chamber position of the J-loop lens, which may reduce the movement of intraocular fluid and tissue.

Endothelial cell loss following phacoemulsification in the pupillary plane.

Endothelial cell loss following posterior chamber phacoemulsification with and without posterior chamber lens implantation was studied. Postoperative cell counts were taken four months after surgery. Three surgeons participated in this study. Posterior chamber phacoemulsification alone (30 patients) resulted in a mean cell loss of 9%, with a maximum cell loss of 22% in one patient. Posterior chamber phacoemulsification with posterior chamber lens implantation (30 patients) resulted in a mean cell loss of 8% with a maximum cell loss of 26% in one patient. Statistical analysis shows no difference in postoperative cell loss between these two groups.

Secondary posterior chamber intraocular lens implants.

Secondary posterior chamber lens implants were performed on sixty-nine patients. Although technically the insertions were slightly more difficult than in a primary case, the results were excellent. Only one eye had vision significantly lower than preoperative level, and this, only a drop from 20/25 to 20/40. Three eyes required a second procedure to suture the lens. One eye suffered detachment later with count fingers vision as the final result.

The Terry surgical keratometer: a 12-month follow-up report.

Postoperative astigmatism was studied in two groups of patients. All patients had undergone phacoemulsification with implantation of a posterior chamber intraocular lens. The incision closure techniques in both groups were identical, with one exception: One group was closed using the Terry keratometer intraoperatively, the second group was closed without the use of this instrument. Two observations are made from the twelve-month data. First, astigmatic error in the Terry group remained constant from the postoperative keratometer readings at six weeks to the twelve-month keratometer readings. Second, while there was a considerable difference in astigmatism at six weeks between the Terry group and the control group (less astigmatism in the Terry group), the differences were no longer apparent at twelve months. Sutures were removed as necessary to improve astigmatism in the control group. No sutures were cut in the Terry group during this twelve-month period.

A comparative analysis of anterior chamber, iris-supported, capsule-fixated, and posterior chamber intraocular lenses following cataract extraction by phacoemulsification.

Representative lens styles of four different intraocular lens groups after cataract extraction by phacoemulsification are compared. Certain cases were excluded to minimize inconsistency. Postoperative visual acuities and complications of each lens type are compared.