Bruce D. Nichols

Implantation of a Posterior Chamber Lens Without Capsular Support During Penetrating Keratoplasty or as a Secondary Lens Implant

We have devised a technique to fixate a posterior chamber lens in the ciliary sulcus when no posterior capsular support exists. Our short-term follow-up of 22 eyes with lenses thus fixated has shown these eyes to be quiet and to have good pupillary motility after at least 3 months. We believe this new technique is a significant advancement in corneal and anterior segment surgery.

AMO array multifocal lens versus monofocal correction in cataract surgery.

PURPOSE To compare the functional capabilities of 15 patients (30 eyes) who had implantation of the Allergan Medical Optics (AMO) Array multifocal intraocular lens (IOL) with those of 13 patients (26 eyes) with an AMO monofocal IOL. SETTING Department of Ophthalmology, The University of Western Ontario, Canada. METHODS The objective capabilities of both groups were analyzed through visual acuity measurements for distance, near, and depth of focus. Subjective functionality was assessed through the use of a questionnaire that included the previously validated VF-14 index of visual function, a global measure of overall satisfaction with visual acuity, and questions related to the frequency of spectacle wear. RESULTS Both groups had excellent corrected and uncorrected distance visual acuity postoperatively. The multifocal group had better acuity than the monofocal group at near with distance correction in place (70% versus 43% achieved J3 or better). The multifocal group also had significantly better depth of focus. Subjectively, both groups indicated high levels of satisfaction with visual function. However, the multifocal group indicated higher levels of satisfaction during the day, at night, and overall without spectacles. This result translated into less spectacle wear for both near and distance in the multifocal group. CONCLUSIONS The results of this study indicate high patient satisfaction with the Array multifocal IOL and greater functional independence from spectacle wear, by objective and subjective patient measures, than with the monofocal IOL.

Corneal endothelial and intraocular pressure changes after phacoemulsification with Amvisc Plus and Viscoat

ABSTRACT A prospective, randomized, observer‐marked study was conducted to compare corneal endothelial and intraocular pressure (IOP) changes after cataract surgery with the viscoelastic agents Amvisc Plus and Viscoat. Forty‐nine patients (50 eyes) who had uncomplicated phacoemulsification and implantation of a posterior chamber intraocular lens were randomly assigned to either Amvisc Plus (25 eyes) or Viscoat (25 eyes) groups. Surgical technique was rigidly standardized in all cases. No significant difference in endothelial parameters or postoperative IOPs measured at 24 hours, one week, and two months was detected by analysis of variance between the Amvisc Plus and the Viscoat groups. Visualization was difficult with Viscoat because of its tendency to retain bubbles. Phacoemulsification energy was related to a loss of endothelial density, regardless of the viscoelastic used. The postoperative beta blocker may have contributed to the lower average postoperative IOP than has been reported.

Visual results following vitreous loss and primary lens implantation

ABSTRACT Implantation of an intraocular lens following vitreous loss at cataract surgery is a controversial decision. To address this issue, we retrospectively identified all cases performed at the University of Minnesota in the last three years that had either a posterior or an anterior chamber lens placed following anterior vitrectomy. Twenty patients had a posterior chamber lens implant; 14 had follow‐up longer than six months. All these patients achieved 20/40 or better visual acuity, although one patient had a retinal detachment. Of the six patients with an anterior chamber lens implant, four achieved 20/40 or better acuity and two achieved 20/50 acuity with follow‐up of six months; one patient had a retinal detachment. This review demonstrates that with a meticulous anterior vitrectomy, good visual results can be achieved, although the risk of retinal detachment is higher than in uncomplicated cases.

Cataracts in systemic diseases and syndromes.

&NA; The last 12 months of ophthalmic literature contained considerable research into the diabetic cataract. Transient, reversible cataracts were described in patients with subclinical diabetes, one of which reported the interesting association of a unilateral cataract with the ingestion of margaritas or citrus juices. Extracapsular cataract extraction with posterior chamber lens implantation was shown to cause the development or progression of background diabetic retinopathy. Other metabolic diseases including hyperprolactinemia, hyperornithinemia, and sorbitol dehydrogenase deficiency have also been associated with cataracts. Research into the clinical findings of Alports syndrome and Lowe syndrome has further defined these entities. Finally, many chromosomal abnormalities have been excluded or included in the pathogenesis of cataracts, thus providing clues to their genetic basis.

Phacoemulsification with aspirated or retained Viscoat

Abstract Endothelial cell counts, morphology, and 24‐hour postoperative intraocular pressure (IOP) changes were measured in 55 consecutive patients (60 eyes) who had uncomplicated phacoemulsification and posterior chamber lens implantation with either aspirated (30 eyes) or retained (30 eyes) Viscoat® (sodium chondroitin sulfate‐sodium hyaluronate). The surgical technique was standardized in all cases. Endothelial cell loss was almost identical in the aspirated and in the retained groups (8.8% and 8.7%). Postoperative pleomorphism was significantly less in the retained Viscoat group than in the aspirated group, suggesting a possible protective effect of the retained viscoelastic. Corneal thickness increased significantly in the retained Viscoat group, but this was not significant clinically. The retained Viscoat group had more patients with a postoperative IOP greater than 30 mm Hg and a greater mean increase in postoperative IOP, although the difference between the groups was not significant. The IOP changes may have been caused by blockage of the trabecular meshwork by the retained Viscoat. The results suggest that Viscoat can be retained after cataract surgery if the surgeon is prepared for a greater 24‐hour postoperative increase in IOP.

Neodymium:YAG Laser Zonulysis for Treatment of Lens Subluxation

Nine eyes with lens subluxation in seven patients (6 patients with Marfans syndrome, 1 with idiopathic lens subluxation) were treated by neodymium:YAG (Nd:YAG) laser zonulysis. The procedure uses an Nd:YAG laser to lyse the zonules to obtain a clear aphakic visual axis. Pretreatment best-corrected visual acuity was 20/60 or worse in eight eyes (6 eyes less than or equal to 20/200). Movement of the crystalline lens was achieved after zonulysis in all cases (100%), and a clear aphakic visual axis, sufficient to maintain aphakic correction without diplopia or glare, was obtained in eight eyes (88.9%). The procedure was combined with optical iridotomy in three cases (33.3%). Five cases (55.6%) required more than one zonulysis treatment. Visual acuity improved two or more Snellen lines in all but one eye (7 eyes greater than or equal to 20/60). Four cases had complications which included: increased intraocular pressure (IOP), mild iritis, recurrent migration of the lens into the visual axis, and crystalline lens damage. The final two complications necessitated eventual surgical removal of the lens. These results suggest that Nd:YAG laser zonulysis may be of benefit as an alternative treatment modality for selected patients with lens subluxation.

Four incision radial keratotomy

ABSTRACT Radial keratotomy is a constantly evolving procedure. This paper investigates the value of four incision radial keratotomy. The possible advantages of fewer incisions include increased corneal stability, lower risk of perforation, less potential of endothelial cell loss, decreased chance of overcorrection, and simplification of the procedure. We evaluated the results of four incision radial keratotomy in 55 eyes of 31 patients. Follow‐up ranged from one to 18 months. Results in low myopia (‐2.00 to ‐3.12 diopters) show 93% of the patients were 20/40 or better, 90% were within ± 1 diopter of emmetropia, and no patients were overcorrected greater than I diopter. In moderate myopia (‐ 3.25 to ‐ 4.37 diopters), 84% of the patients were 20/40 or better, 92% were within &agr; 1 diopter of emmetropia, and no patients were overcorrected greater than 1 diopter. Regression analysis was performed and it was determined that the postoperative result was equal to .262 + [1.293 x preop spherical equivalent] ‐ [1.166 x optical zone] + [0.56 x depth] + [.038 x age], R = .87.

Complications of Nadbath facial nerve block and a review of the literature

In a retrospective study of complications resulting from the Nadbath facial nerve block, we identified three patients (0.25%) over a 2-year period. Complications included dysphonia, laryngospasm, unilateral vocal cord paralysis, and a sensation of the inability to breathe. As it exits the stylomastoid foramen, the facial nerve lies close to the vagus, glossopharyngeal, and accessory nerves. Particular care must be taken, therefore, when giving Nadbath blocks in very thin individuals. The use of hyaluronidase, which enhances effusion of the anesthetic agent, should probably be withheld.

The Surgical Management of Overcorrection in Myopic Epikeratophakia

Three patients underwent myopic epikeratophakia that resulted in overcorrection. The surgical management of these cases involved resuturing the myopic lenticule to flatten the peripheral curvature and reduce the amount of minus power. A reduction in the overcorrection was achieved in all cases.