Monocular Cataract Research Articles

Effect of cataract surgery on the progression of diabetic retinopathy

Purpose: To study the effect of cataract surgery and other factors on the progression of diabetic retinopathy using the nonoperated contralateral eye as a control. Setting: Department of Ophthalmology, Catholic University Medical College, Uijongbu St. Mary’s Hospital, Seoul, Korea. Methods: Monocular cataract surgery was performed in 75 patients who had the same degree of retinopathy or no retinopathy in both eyes preoperatively. Patients were assigned to 1 of 2 groups as follows: Group A, progression of retinopathy in the operated eye caused by cataract surgery; Group B, no progression of retinopathy bilaterally, comparable level of progression in both eyes, or more progression of retinopathy in the nonoperated eye than in the operated eye. The differences between the 2 groups in age, duration of and treatment methods for diabetes, renal function, and presence of preoperative macular edema were compared. The 1-year follow-up included evaluation of the progression of retinopathy. Results: Surgery caused the retinopathy to progress in 23 patients (30.6%, Group A); 52 patients (69.4%, Group B) had no progression of retinopathy or a comparable level of retinopathy postoperatively. The operated eye had more progression of retinopathy than the nonoperated contralateral eye ( P < .05). There was no significant difference between the 2 groups in age, diabetes duration, surgical method, or hypertension. Preoperative macular edema and poor renal function significantly affected the progression of diabetic retinopathy after cataract surgery ( P < .05). Conclusions: Diabetic retinopathy progressed after cataract surgery. The presence of preoperative macular edema and poor renal function increased the progression of retinopathy postoperatively.

High Levels of Binocular Function Are Achievable after Removal of Monocular Cataracts in Children

Lions Eye Institute, Albany, NY Original study reprint requests: Albert W. Biglan, 3518 Fifth Ave., Pittsburgh, PA 15213-3387.

High levels of binocular function are achievable after removal of monocular cataracts in children before 8 years of age

Objective To investigate the visual acuity and binocular function results achieved in children who had monocular cataracts removed before 8 years of age. Design Retrospective, noncomparative case series. Participants Clinical records of 171 patients who underwent a unilateral cataract removal between January 1986 and 1996 were reviewed retrospectively. Seventy-four eyes were included in the study: 19 congenital, 11 developmental, 19 posterior lenticonus, 19 traumatic, and 6 complicated cataracts. Patients with less than 2 years of follow-up; eyes with cataracts resulting from retinoblastoma; prematurity; and those associated with dense corneal scars, lens dislocation, and persistent hyperplastic primary vitreous were excluded. Intervention Visual acuity was measured by means of age-appropriate tests such as the fixation pattern, Allen object recognition cards, isolated optotypes with the Sheridan Gardiner test, and Snellen letters. Sensory fusion was assessed with the Worth 4-dot test, and stereo acuity was assessed with the Titmus stereo test. Main outcome measures Cataracts were classified regarding type, extent, age at onset, duration of the opacity, age at surgery, method of removal, development of secondary membrane , form of optical rehabilitation, and presence of strabismus. Visual acuity levels between 6/6 and 6/12 were considered “good.” Fusion of the Worth 4-dot test at distance and near, and presence of stereo acuity of 100 seconds of arc or better were considered “good” binocular function. Multiple logistic regression analysis was used to define factors that correlated with achieving good visual outcome. Results Visual acuity was 6/12 or better in 27 (36.5%) eyes. However, good binocular function was achieved in only 11 of these 27 patients. Results of univariate analysis showed that later age at onset of cataract and absence of strabismus were significant for good visual acuity and binocular function. The presence of strabismus increases the risk of not achieving good visual acuity by 5.45-fold. Conclusions Good visual acuity and binocular function can be achieved after removal of monocular cataracts in visually immature children. Patients with strabismus at presentation or during the follow-up period have the least chance of achieving a good sensory result.

The relationship between stereopsis and monocular optokinetic nystagmus after infantile cataracts

Purpose: Visual deprivation disrupting binocular development, such as that occurring with congenital cataract, is reported to cause asymmetric monocular optokinetic nystagmus (MOKN), as well as poor sensory and motor fusional outcome. We wanted to determine if symmetric MOKN could develop in cases of congenital cataract with good fusional outcome. Methods: We tested MOKN (with video and electro-oculographic recordings) and stereoacuity on 5 patients with good visual acuity and satisfactory ocular alignment after surgery for congenital cataract. Results: Stereoacuity was better than 50 seconds of arc in 1 case of monocular cataract and 2 cases of bilateral cataract. These case patients had symmetric MOKN. In a monocular cataract case, symmetric MOKN was observed in spite of questionable stereoacuity (at least 500 arc/s). One patient showed asymmetric MOKN, despite good visual acuity, and stereoacuity of 200 arc/s. Conclusions: Patients with congenital cataract can have symmetric MOKN and good stereopsis. These cases suggest that MOKN symmetry develops along with good stereopsis, but the quality of stereopsis necessary for development of MOKN symmetry remains unclear. (J AAPOS 1999;3:221-6)

Results following secondary intraocular lens implantation in children

Placement of a secondary intraocular lens (IOL) in a child may be considered in children with congenital monocular cataracts who have had complete opacities removed early in life and who later become contact lens intolerant, in eyes that have received trauma which precluded placement of a primary IOL, and in young adults who have bilateral aphakia who become resistant to use of contact lenses or spectacles. Clinical records of all children in our practice who received a secondary IOL between January 1988 and December 1994 were reviewed. Indications, biometry, type of procedures, preoperative and postoperative acuity, refractive error, binocular status, and complications were studied. During the 7-year period, 242 cataract operations were performed. Fifty-nine eyes received a lens implant, and 28 of these were secondary implants. There was a mean interval between the initial cataract operation and the procedure for the secondary implant of 77 months. The mean follow-up was 35 months (range, 3 to 71) for the 28 eyes that received a secondary implant. Two received anterior chamber implants. Eight eyes had insufficient capsular support for an IOL. Six implants were placed in the posterior chamber and required suture fixation to the sclera. Twenty of 28 eyes had a measurable improvement in visual acuity. Only 1 eye had a decrease in visual acuity of 2 lines. Fifteen patients (54%) had a final refraction within 1.50 diopters of the fellow eye, and 75% were within 3.00 diopters. During the follow-up period, 2 eyes developed glaucoma. One had a transient pressure elevation, and the second has required 2 filtration procedures. Three patients required a Nd: YAG capsulotomy. Six patients demonstrated Worth fusion at distance and near, but only 3 patients demonstrated 200 seconds of arc or better stereo acuity. Placement of contemporary-style, secondary intraocular lenses in children and young adults appears to provide a safe and effective alternative for correction of aphakia in children who become contact lens or spectacle-intolerant.

A Prospective Study of Ocular Hypertension and Glaucoma after Pediatric Cataract Surgery

Late-onset glaucoma can occur after pediatric cataract surgery. However, no large prospective study of the prevalence of ocular hypertension and glaucoma after pediatric cataract surgery has been performed. A prospective glaucoma evaluation was offered to all eligible subjects at least 5 years after automated lensectomy and vitrectomy for pediatric cataracts. Sixty-two (58%) of 107 eligible subjects received a glaucoma evaluation. One (4.5%) of 22 patients with bilateral cataracts had glaucoma, and a much higher percentage (45%) had ocular hypertension. Five (12.5%) of 40 patients with unilateral cataracts had glaucoma, and an additional 32.5% had ocular hypertension. For patients with monocular cataracts, the age and corneal diameter at the time of cataract surgery were related to the subsequent development of ocular hypertension or glaucoma. The majority of subjects were able to cooperate with a comprehensive glaucoma examination that included cycloplegic refraction, determination of intraocular pressure, examination of the optic nerve, and fundus photography, without requiring sedation. There is a high prevalence of ocular hypertension after pediatric cataract surgery. Children who are 5 years of age and older usually are able to cooperate with a glaucoma evaluation. The natural history of ocular hypertension after pediatric cataract surgery will be determined with longitudinal studies in the future.

Stereopsis After Congenital Monocular Cataract Extraction

Congenital monocular cataract extraction was performed on a 1-day-old baby girl and a hydrophilic contact lens was fitted. A progressive regimen of part-time occlusive therapy was then instituted. Eight years later, the girl has a visual acuity of 20/25 in the operated-on eye and 50 seconds of arc of stereoacuity that has been confirmed by an independent pediatric ophthalmologist. This patient demonstrates the potential for high-grade stereopsis in congenital monocular aphakia.

Is the phakic eye normal in monocular pediatric aphakia?

This retrospective review of 97 pediatric patients who underwent monocular surgery for congenital or developmental cataracts studied the incidence of abnormalities in the contralateral phakic eye. Fifty-nine percent of patients had a normal phakic eye. However, 40 patients showed at least one abnormality in the phakic eye: reduced vision (21%), nystagmus (19%), cataract (15%), iris heterochromia (9%), myopia (6%), microphthalmos (6%), pupillary miosis (2%), congenital glaucoma (2%), optic nerve abnormality (2%), aniridia (1%), and corneal opacity (1%). Not all abnormalities were detected at the time of diagnosis of the contralateral cataract. The more significant findings of reduced vision and nystagmus in the phakic eye were usually detected postoperatively, often several months after the optimum time for treatment of pediatric cataracts. We suggest that monocular cataract surgery not be delayed. This will allow the best vision to be obtained for the aphakic eye, as the "sound eye" may not always be normal in monocular pediatric aphakia.

Neonatal cataract: aetiology, pathogenesis and management.

We review the epidemiology, aetiology, pathogenetic mechanisms and clinical management of neonatal cataract. Visual development and the effects of visual deprivation in the infant with congenital cataract are discussed and related to the timing of surgery. Surgical techniques and the important operative and post-operative complications are discussed. We review post-operative management and compare the different techniques available for aphakic correction, and describe the VEP changes found in patients with monocular cataract.

Traumatic cataract surgery with intraocular lens implantation in children.

We evaluated our experience of intraocular lens implantation in 22 children with uniocular traumatic cataract. Good visual acuity was achieved in a large proportion of the children despite associated corneal opacities and several intraoperative and postoperative complications. Our study suggests that intraocular lens implantation may have a major role in management of monocular cataracts in children.

Inhibition of Binocular Contrast Sensitivity in Hypermetropic Anisometropia

Binocular contrast inhibition can occur when the monocular contrast sensitivities are not equal. It has been reported in cases of monocular cataracts. Our case is an 18-year-old female with 3.50 D of hypermetropic anisometropia. She was not amblyopic but showed a typical binocular contrast inhibition.

Effects of Aphakia on the Geniculostriate System of Infant Rhesus Monkeys

The effects on the visual system of rearing rhesus monkeys with monocular aphakia, corrected with extended-wear contact lenses, were assessed with anatomical, electrophysiological and behavioral methods. The major finding was that the effects of the various treatments on the aphakic eye varied in degree depending upon the amount of focused pattern input received by the aphakic eye compared to its fellow eye. The behavioral, electrophysiological and anatomical assessments of the treatment effects on the aphakic eyes correlated closely with each other. Because this experimental paradigm is similar to current clinical procedures for treating human infantile monocular cataracts, it provides a nonhuman primate model for studying aphakia.

Epikeratophakia-Present Results in Infants with Unilateral Cataract and Future Prospects

The management of monocular infantile cataract presents a difficult and challenging clinical problem. The methods used for optical correction after cataract removal include contact lenses, intraocular lenses and epikeratophakia. Epikeratophakia offers a permanent optical correction and eliminates the risks of intraocular procedures. Epikeratophakia is best suited for infants with uniocular aphakia who are contact lens non-compliant and who are still young enough to benefit from amblyopia therapy. The preoperative evaluation, the surgical technique, the postoperative management of epikeratophakia as well as the results of the Louisiana State University and the nationwide studies are presented. Future perspectives in the methods of preparation and preservation of epikeratophakia lenticules and the use of glues and synthetic materials are discussed.

Visual Acuity in Monocular Pediatric Aphakia: Does Epikeratophakia Facilitate Occlusion Therapy in Children Intolerant of Contact Lens or Spectacle Wear?

Twenty-two children had a monocular cataract extracted between 1981 and 1986. Twelve of these patients eventually tolerated a monocular contact lens or anisometropic spectacle wear. Eleven patients initially would not tolerate conventional therapy, and epikeratophakia was performed. Of the 12 patients tolerating a contact lens or spectacles, eight (67%) now see 20/60 or better, and six (50%) see 20/40 or better. Only one (10%) of the patients maintaining the epikeratophakia graft developed vision as good as 20/70. Epikeratophakia did not facilitate occlusion therapy for amblyopia. The critical factor in the development of good vision following monocular cataract extraction was the patient's willingness to patch the better eye, not the method of correcting the refractive error.

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.

Visual Results After Surgery for Monocular Juvenile Cataracts of Undetermined Onset

Seventeen of 216 operations I performed for juvenile cataract were in patients between 1 and 51/4 years of age who had monocular cataract of unknown origin and unknown time of onset. In 14 of them final visual acuities were 20/50 or better. In an additional eight children in whom the age at onset of the cataract could not be determined with certainty, but in whom microphthalmos suggested that it was congenital, the visual results were uniformly poor. Surgery for a monocular cataract of undetermined onset in a young child without microphthalmos may carry an excellent prognosis.

Abnormal Sensory Findings Secondary to Monocular Cataracts in Children and Strabismic Adults

Three children between the ages of 4 and 6 years had untreated monocular traumatic cataracts, for several years. Although amblyopia did not develop, there was a disruption of fusion that resulted in horror fusionis after cataract surgery. Two adults with strabismus and amblyopia since childhood developed cataracts as adults. The occlusion caused by these long-standing cataracts appeared to eliminate suppression and resulted in horror fusionis.

Cataract operation with anterior chamber lens implant

The results of 106 intracapsular cataract extractions with implantation of an anterior chamber lens are reported. The indications were monocular cataract in 63%, bilateral cataract in 15%, cataract with maculopathy in 10%, practical monocularity, parkinsonism etc. in 12%. Postoperative visual acuity was 0.4 to 1.0 in 88%; diminished vision was caused by maculopathy, central venous thrombosis, or glaucoma in 12%. Postoperative complications: pupillary block in 8.5%, glaucoma in 10.5%, cystoid macular edema in 3.6%, and decentration of implant in 1%. The need for postoperative care of patients with intraocular implants after cataract surgery is pointed out.

Intraocular Lens Implantation in Children with Monocular Cataracts: 1974–1983

Two hundred twenty-five consecutive intraocular lens (IOL) implants performed by the same surgeon from 1977 to 1983 are reviewed. Ninety (40%) patients had traumatic cataracts and 135 (60%) patients had infantile cataracts. Fifty-four percent of the patients presented with preoperative complications. The most frequent were corneal scars (62%) in the traumatic cataract patients, and posterior lenticonus (18%), microphthalmia (16%), PHPV (14%), and optic nerve defects (12%) in the infantile cataract patients. The iris suture lens was implanted from 1973 to 1982, but the posterior chamber lens is now the most frequently implanted primary IOL. Flexible anterior chamber or iris suture IOLs are used as secondary implants. Followup ranged from six months to nine years. Postoperatively, 66% of the patients required spectacles for residual optical correction and 55% required occlusion for amblyopia. Postoperative complications consisted of post-pseudophakos membranes (13%), peripheral iris erosion (13%), iris sphincter erosion (18%), dislocated IOLs (7%) and corneal edema (4%), Secondary surgical procedures relating to the IOL were discissions of post-pseudophakos membranes (8 patients), refixation of dislocated lens (15 patients) and IOL removal (6 patients). The best corrected visual acuities during the course of the followup was 20/20 to 20/40 in 34% of the patients, 20/50 to 20/100 in 21%, 20/200 in 12%, and less than 20/200 in 33% of patients. Sixty percent of the traumatic cataract patients achieved 20/20 to 20/40 acuity and 17% of the infantile cataract patients achieved this level. Primary implantation patients achieved superior acuities over secondary implantations in both groups.

Congenital Cataract and Intraocular Lenses

We implanted nine intraocular lenses for the aphakic correction of congenital monocular cataracts in eight children (eight eyes). During follow-up periods ranging from 18 to 50 months in six children, there were no major complications connected to the surgery. Parental cooperation with treatment for amblyopia was satisfactory in all cases. The degree of strabismus, the fixation pattern, and the optokinetic nystagmus responses improved postoperatively in all six. Three children old enough to cooperate during visual testing had visual acuities better than 20/200 and two of these had visual acuities of 20/40. In all six children the sound eye is still patched for three to six hours a day. All six attend regular kindergartens and participate in their normal activities without difficulty.