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Biomedical subjects

A R Pilkerton

Publications and source records attributed to A R Pilkerton.

11 recordsLinked to original sources

A new technique for repositioning and fixating a dislocated intraocular lens.

A new technique for repositioning and fixating a dislocated posterior chamber intraocular lens is described. Using pars plana vitrectomy techniques, the intraocular lens is retrieved and maintained in the plane of the ciliary sulcus. The lens haptics are sutured to the sclera in three positions to avoid recurrent dislocation or torsion of the lens. Intraocular manipulation of sharp needles is avoided. Suture knots are buried in the sclera to minimize the risk of late-onset endophthalmitis.

Aged

Idiopathic preretinal fibrosis: a review of 237 cases.

We reviewed the charts of 223 patients (236 eyes) with idiopathic preretinal fibrosis, dividing them into two groups: those who only had been observed, and those who, after an observation period, had the membranes surgically removed. All of the patients had been followed from 6 to 120 months (mean, 29 months). Vision in the nonsurgical group slowly deteriorated and was accompanied by metamorphopsia. More rapid visual deterioration occurred in 60 eyes (25%), of which 37 (16%) required surgery. Vision in 78% of the surgical group improved, with the greatest subjective benefit considered to be subsidence of metamorphosia. Vision spontaneously improved in 2.5% of the cases.

Aged

An alternative technique of local anesthesia for vitreoretinal surgery.

Retrobulbar anesthesia produces effective local anesthesia for ocular surgery, but significant complications have been reported with its use. To maintain its efficacy and to minimize the risks associated with the passage of a needle behind the eye, we have placed local anesthesia into sub-Tenon's space posteriorly using a blunt irrigating cannula in 100 patients undergoing vitreous or retinal procedures. Posterior Tenon's capsule is opened by blunt dissection, allowing the irrigating cannula to be passed into the posterior sub-Tenon's space for anesthetic injection. The technique was effective in 98 of 100 patients, and no morbidity was associated with its use.

Anesthesia, Local

Rhegmatogenous retinal detachment with a pit of the optic nerve head.

A 56-year-old myope developed a retinal detachment of the macular area and the temporal quadrants in his left eye that harbored a temporally-located pit of the optic nerve head. Under anesthesia a small peripheral retinal break was identified, and the retina was reattached successfully using cryotherapy and a limited scleral buckling procedure. Peripheral retinal breaks should be searched for in myopic eyes with optic pits and retinal detachments involving peripheral retinal quadrants.

Humans

Experimental vitreous fibroplasia following perforating ocular injuries.

Biochemical data and histopathologic observations were made on an experimental model of vitreous fibroplasia in the rabbit eye, with comparisons between the change in vitreous collagen concentration and histologic characteristics 7, 14, and 30 days after injury. Prior to two weeks after injury there is a relatively small amount of new vitreous collagen formed, associated with an inflammatory and vascular reaction. At four weeks there is a marked increase in new vitreous collagen and dense fibrous sheets are noted. Vitreous hemorrhage accelerates collagen formation, and methylprednisolone sodium succinate does not decrease vitreous fibrosis. Our results suggest that the optimum time for vitrectomy, under the conditions of this experiment, is two weeks after primary repair. The efficacy of steroids in retarding vitreous fibroplasia is not supported.

Animals

Retinal adhesion in light- and dark-adapted rabbits.

The effects of pigmentation and light exposure on retinal adhesion in rabbits have been investigated in a complete factorial experiment. Ocular pigmentation did not significantly influence retinal adhesion. A significant difference in retinal adhesive forces was found between light and dark adaptation. The force required to detach the retina from the retinal pigment epithelium was 20 per cent greater in light-adapted eyes than in dark-adapted eyes. These observations suggest that the positional change of rhodopsin molecules in the outer segment disk membranes occurring with light exposure and the resultant alteration in interdisk electrostatic forces may play an important role in retinal adhesion.

Adaptation, Ocular