Monocular Patients Research Articles

Compliance with safety glasses wear in monocular children.

Many ophthalmologists prescribe polycarbonate "safety glasses" to protect the remaining eye of monocular patients. Others do not routinely do so when the remaining eye is emmetropic since they feel compliance is poor. To evaluate compliance with safety glasses wear in these children, we reviewed the charts of all children (< 21 years old) treated with enucleation and followed at the University of Iowa by the Pediatric Ophthalmology Service between 1962 and 1991. Safety glasses were defined as polycarbonate lenses in a frame suitable for protective wear with spherical equivalent < or = -0.75 or < or = +2.00 diopters. Fifty-six patients were followed after enucleation. Forty-six of these patients met the inclusion criteria and 33 patients were available for follow up. Eighty-five percent of patients wear safety glasses > or = 50% of their waking hours; 61% wear them > or = 80% of the time; 33% wear them 100% of their waking hours. Twenty-one of the 33 patients participate in sports. One hundred percent of the female participants and 80% to 93% of the male participants wear safety glasses, goggles, or face shields during sports. Fifteen of the 33 respondents reported at least one potentially serious accident in which the safety glasses had protected the good eye. Compliance with safety glasses wear appears to be good in this population and may prevent injury to the remaining eye.

Early Clinical Experience with the Baerveldt 350-mm2 Glaucoma Implant and Associated Extraocular Muscle Imbalance

The Baerveldt glaucoma implant is a new commercially available aqueous drainage device. Clinical data on the performance of the implant are relatively limited. The purpose of this investigation is to explore potential advantages and disadvantages of this implant over the more widely used Molteno implant. Retrospective analysis was performed on 37 eyes of 36 patients with refractory glaucoma who underwent placement of a mid-sized Baerveldt 350-mm2 implant. Patient selection was based on previous failure of conventional medical, laser, and surgical management, with poor prognosis for further glaucoma surgery and adjunctive antifibrosis therapy. Significant postoperative extraocular motility restriction and heterotropia were found in the operated eyes. Twenty-three (77%) of 30 eyes measured have significant heterotropia in primary gaze and restriction of gaze into the quadrant of the implant. As a result, 11 (65%) of 17 functionally binocular patients have diplopia in primary gaze. Pending further study, the authors are avoiding placement of the Baerveldt 350-mm2 implant in both binocular and monocular patients due to the high frequency of induced heterotropia and motility restriction.

Intraocular lens implantation in developing countries

One of the chief aims of ophthalmic workers in developing countries is to operate on as many cataract patients as possible in the most costefficient manner. Therefore, our intraocular lens (IOL) implantation policy in Nakuru and Kikuyu, Kenya, is to reserve IOLs for monocular cataract patients of all ages, who otherwise would not have use of the aphakic eye. In this study, we review 105 of our first IOL implantations. In 60%, the uncorrected postoperative visual acuity was 20/60 or better.

Recovery after loss of an eye.

Recovery after loss of one eye requires an adjustment to monocular vision and resolution of a significant, serious emotional trauma. The impact on everyday life is not well documented. We surveyed 125 monocular patients by questionnaire regarding their recovery. Eighty-five of 125 respondents reported that loss of one eye had not changed their life in any permanent way. Only seven reported persistent visual problems, whereas 12 described problems in employment and 21 had anxiety or poor self-image. Among 49 adults who had suddenly lost a sighted eye, 50% reported that their adjustment period for driving, work, recreation, home activities, or walking was less than 1 month. Ninety-three percent thought that their adjustment was completed by 1 year. In conclusion, most patients were able to resume everyday activities after a short period of adjustment. Problems with employment and self-image were frequent, but visual problems were unusual.

Binocular vs. monocular task performance.

Functional advantages of binocularity were investigated by having 13 subjects perform a group of occupational-type tasks under monocular and binocular conditions. Significant binocular advantages ranging from 29.5% (pointers in straws) to 3.7% (reading speed) were measured. Tasks with many disparity cues showed the greatest binocular advantage. This shows that patients with normal binocular vision use binocular cues, most likely stereopsis, to enhance performance. In a second experiment, three subjects with normal binocular vision underwent monocular occlusion for 5 days to investigate whether monocular skills improved to compensate for the loss of binocular vision. During that period binocular performance was consistently better than monocular performance, and both monocular and binocular performance improved, even though the subjects were only gaining monocular experience. Although the 5 day occlusion period does not simulate the long-term denial of normal binocularity that strabismics or monocular patients experience, it shows that binocular superiority remains after short-term loss of binocularity.

The Question of Ocular Tolerance to Intravitreal Liquid Silicone: A Long-term Analysis

The authors report a retrospective review of 407 eyes that received intravitreal liquid silicone between 1961 and 1984. Initial anatomical success was noted in 270 eyes (66.3%), while initial functional success was achieved in 103 eyes (25.3%). Ten years postoperatively, approximately half of the eyes with initial functional success still had functional vision (49.2%). These eyes had less advanced proliferative vitreoretinopathy and fewer inferior breaks than others. Recurrent retinal detachment rather than late complications was the predominant cause of functional failure in those eyes losing functional vision in less than ten years postoperatively. Late complications were common and frequently required therapeutic intervention. Intravitreal liquid silicone was of great benefit to many monocular patients, but of little benefit to the binocular patients in our series.

Epikeratophakia—The Surgical Correction of Aphakia: Update 1981

Epikeratophakia grafts used to rehabilitate vision in adult monocular aphakic patients intolerant of contact lens correction or not candidates for IOLs were studied prospectively. Thirty-two patients who entered this study between its inception in February 1980 through February 1981 were followed for at least eight months. Patients with normal visual potential before surgery had average visual acuities with spectacle overcorrection of 20/50 at four months, 20/40 at eight months, and 20/30 at one year. Few long-term complications were seen. Empirical modification of the lathing process has decreased the undercorrection from the 5.5 diopters seen in the early patients to the 1.0 diopter seen in the more recent patients. Problems with predictability are related to the behavior of preserved corneal tissue during the lathing and the healing of these lamellar grafts. This procedure is intended for aphakic patients for whom IOL and contact lens correction is not possible.

One-Stage Lower Eyelid Reconstruction

SUMMARY A technique for reconstruction of 75% to 90% of the lower eyelid is presented. This procedure utilizes a large tarsoconjunctival graft in conjunction with an advancement skin graft from the cheek. This one-stage approach is valuable in lower eyelid reconstruction in monocular patients.

Corneal response to a provocative test in aphakic patients

In troduc t ion Clinically we find little oedema in aphakic patients wearing low oxygen transmissibility hydrophilic lenses. However, this is not in accordance with the oxygen needs of the normal cornea as reported by Mandell et al 12. This would suggest that there are metabolic differences between the corneas of normal and aphakic eyes. Such an assumption is supported by Holden et at 3 who found that the swelling of the aphakic eye was inferior to that of the normal fellow eye when fitted with lenses of identical thickness. Therefore, the present investigation was devised to assess certain aspects of corneal metabolism of a group of monocular aphakic patients where both eyes were fitted with lenses of similar oxygen transmissibifity.

Fusional Ability in Monocular Aphakic Patients: Contact vs. Intraocular Lenses

Fusional Ability in Monocular Aphakic Patients: Contact vs. Intraocular Lenses

Stereoscopic Acuity Measurement in Aphakia

We performed a variety of tests to assess binocular function on monocular aphakic patients wearing contact lenses, monocular pseudophakic patients, bilateral spectacle-wearing aphakic patients, bilateral aphakic contact lens wearers, and bilateral pseudophakic patients. Stereoscopic acuity levels at distance and near when visual acuity was at least 6/12 (20/40) provided the most useful data. Pseudophakic patients and contact lens wearers performed equally well and outperformed spectacle wearers. Implant patients did not have superior stereoscopic acuity.

Monocular Aphakia and Contralateral Pseudophakia

The implanatation of an intraocular lens into the contralateral eye of non-implanted monocular aphakic patients is reviewed. The specific indications, contraindications, and advantages are discussed. The results of a series of 31 cases are presented and analyzed. The generally good results and specific advantages of this technique, when utilized under proper conditions, indicate that it merits inclusion in the ever expanding spectrum of options available to the modern cataract surgeon.

The use of I-125 Labelled Di-Iodofluorescein : In the Detection of Human Intraocular Neoplasms

The new method which is described is believed to be superior to the usual method for detection of intraocular tumors using P/sup 32/. Because of the limited penetration of beta rays, the use of P/sup 32/ imposes relatively strict geometric restrictions and its usefulness in posterior-segment tumors is limited. The patient receives a single intravenous injection of 5.0 mu c/kg body weight of diiodofluorescein-I/sup 125/, the specific activity of which is 17 mg/mc. External counting over each closed eye is carried out with a hand scintillation counter 1, 5, 8, and 24 hr after injection. Ocular counts are performed by resting the window of the counter against the closed lids; the cavernous sinus is measured by placing the counter just above the bridge of the nose. ln the 17 patients studied, eyes with neoplasms contained at least 23% more radioactivity after 8 hr than did the healthy eye. Control eyes, not containing neoplasms (idiopathic retinal detachment, retinoschisis, benign nevus, macular degeneration, phthisis bulbi, absolute glaucoma), showed less than a 13% differential. One false negative test was obtained, a patient with a metastatic bronchogenic adenocarcinoma to the choroid; no false positives were seen. Diiodofluorescein labeled with I/sup 131/ has been widelymore » used as a diagnostic aid in suspected intracranial neoplasms. However, since the gamma rays of I/sup 131/ have a half-value layer in tissue of 6.9 cm, it has not been helpful in ocular disease; the gamma rays arising from the cavernous sinus interfere with accurate counting of intraocular radiation. I/sup 125/ decays by a complicated scheme, the most important as far as ocular studies are concerned being soft photons of 27.3 and 35.4 kev energies. It has a half-value layer in tissue of 1.9 to 2.5 cm. Therefore, it is feasible to measure radiation of the posterior globe with only minimal interference from radiation arising in the brain sinuses. Its half-life of 60 days results in a greatly increased shelf-life of tagged compounds than when I/sup 131/ is used. Additionally, it has a lower energy of radiation than I/sup 131/ which reduces shielding requirements and permits more efficient detector design. These factors permit enhanced counting efficiency and scanning resolution and lead to a decreased dosage of radiation to the patient. It is thus permissible to use the compound in children in whom P/sup 32/ counting is generally considered contraindicated. However, although the total-body irradiation received during this test is not excessive, it has not been used in pregnant women. The administration of Lugol's solution prior to the test prevents excessive concentration of any free circulating radioactive iodine in the thyroid gland. Diiodofluorescein-I/sup 125/ is not retained by intraocular neoplasms for prolonged periods of time, the most significant counts appearing 8 hr after intravenous injection. About 50% of the injected dose is excreted in the urine and feces within the first 24 hr after injection. The absolute count found in the eye after 8 hr is in the order of 40,000 cpm. After 24 hr, this decreases to approximates 15,000 cpm. The ratio of counts over liver, thyroid, eye, and cavernous sinus is about 4 : 2 : 1 : 0.4. The ratio of counts between the 2 eyes is more significant than the absolute number of counts. This may limit the usefulness of this procedure in monocular patients. (H.H.D.)« less