Interocular interactions during acuity measurement in children and adults, and in adults with amblyopia

The binocular interactions that occur during dichoptic and binocular viewing were investigated using a letter acuity task in normally sighted children (age range 6-14 years) and adults, and in adults with anisometropic amblyopia. Our aims were to investigate the nature of binocular interactions that occur in each group, and the extent to which the characteristics of binocular interactions differ across the groups. The non-tested eye was occluded during monocular (baseline) viewing, and was allowed to view a uniform stimulus with fusion lock in dichoptic viewing. In adults and children with normal vision, acuity under dichoptic viewing was unchanged relative to monocular baseline in the dominant eyes, while acuity of the non-dominant eye improved under dichoptic viewing relative to baseline. The magnitude of dichoptic change in the non-dominant eyes was similar in the two normally sighted groups, but the dichoptic advantage was found to decrease with increasing age within the children tested. Binocular acuity was better than monocular acuity in normal subjects, and a decrease in binocular summation with age was noted within the age range of the children tested. In contrast, the amblyopic observers showed no change in acuity with viewing conditions. The results demonstrate development of interocular interactions during childhood, and wide inter-individual variation in pattern of interocular interactions among anisometropic amblyopic adults.     

Center-surround inhibition deepens binocular rivalry suppression

When dissimilar stimuli are presented to each eye, perception alternates between both images--a phenomenon known as binocular rivalry. It has been shown that stimuli presented in proximity of rival targets modulate the time each target is perceptually dominant. For example, presenting motion to the region surrounding the rival targets decreases the predominance of the same-direction target. Here, using a stationary concentric grating rivaling with a drifting grating, we show that a drifting surround grating also increases the depth of binocular rivalry suppression, as measured by sensitivity to a speed discrimination probe on the rival grating. This was especially so when the surround moved in the same direction as the grating, and was slightly weaker for opposed directions. Suppression in both cases was deeper than a no-surround control condition. We hypothesize that surround suppression often observed in area MT (V5)-a visual area implicated in visual motion perception-is responsible for this increase in suppression. In support of this hypothesis, monocular and binocular surrounds were both effective in increasing suppression depth, as were surrounds contralateral to the probed eye. Static and orthogonal motion surrounds failed to add to the depth of rivalry suppression. These results implicate a higher-level, fully binocular area whose surround inhibition provides an additional source of suppression which sums with rivalry suppression to effectively deepen suppression of an unseen rival target.     

Strabismus and diplopia as complications after cataract surgery with IOL implantation

Summary In our Department of Orthoptics we have seen an increasing number of patients suffering from diplopia after cataract surgery with IOL implantation. Between 1993 and 1997 the total number of patients with this problem was 24 (2.7 % of all patients, mean age 71 years, age range 38–88). We addressed the question of whether there is a common pattern of motility dysfunction. Methods: After evaluation of the clinical history and the basic ophthalmological findings the following parameters were examined: binocular function (Bagolini test), squint angles (Maddox cross), ocular motility. Results: The 24 patients could be divided up into three groups. Group 1 consisted of 9 patients (mean age 82 years, range 64–88) who complained about diplopia because of strabismus incomitans with vertical deviation and restricted motility on the first day after surgery. In 8 of the 9 patients strabismus surgery was done. Group II consisted of 10 patients (mean age 66 years, range 38–77) who noticed diplopia and strabismus within 7 days after surgery. We found various kinds of heterotropia. Seven of these patients were operated on and two had a prism correction. Group III consisted of 5 patients (mean age 67 years, range 61–78). Their already known strabismus paralyticus or concomitans deteriorated, leading to diplopia in some cases. All patients in this group were operated on. Discussion: For group I we believe that retro-, para- or peribulbar anesthesia caused the motility dysfunction. In groups II and III it is unlikely that local anesthesia had a causative role. The prolonged disruption of binocular vision and the abrupt change in the sensory situation after the cataract operation with lens implantation may be the leading causes for strabismus or deterioration of a preexisting strabism, respectively. Conclusions: These patients need a subtil meticulous diagnostic work-up and follow-up because of the possibility of early surgical therapy, which has a good prognosis. Evaluation of binocular vision and eye movements prior to cataract surgery appears to be helpful for later strabismic surgery.      

Early and delayed consecutive exotropia following a medial rectus faden operation

Summary The main advantage of the bilateral medial rectus faden operation (posterior fixation suture) for the treatment of essential infantile esotropia is the low occurrence of delayed consecutive exotropia. Nevertheless, this unwanted complication also occasionally occurs after a faden operation. Patients: All patients operated on between 1988 and 1997 for subsequent exotropia following bimedial faden operations without recessions were included in this study. Surgery for exotropia consisted of uni- or bilateral lateral rectus muscle recession or in removing the faden with or without resection. Results: Within the 10 years examined a bimedial faden operation (without recession) was performed in 1569 patients. In the same period 49 patients were operated on for a consecutive exotropia after a faden operation. Thirty-four (69.4 %) of the consecutive exotrope patients showed exodeviation immediately following the surgery (group I). Fifteen (30.6 %) patients developed manifest exotropia 1–53 months later (group II). The hyperopia at the time of the first operation was 2.5 D in group I and 2.3 D in group II (spherical equivalent). A bimedial faden operation with simultaneous shortening of the anterior muscle segment was performed in four patients in group II and only in two patients in group I. Cerebral palsy was evident in three patients in group II and also so in three patients in group I. Conclusion: Exotropia appearing immediately after surgery is most likely the result of an individually overdosed operation. This conclusion is not sufficient for delayed exotropia. Motor and sensory instabilities, such as those in patients needing a faden operation with simultaneous shortening of the anterior muscle segment for the treatment of convergence excess with no deviation at far or in patients showing cerebral palsy, seem to increase the risk of delayed consecutive exotropia. The mean interval between the initial surgery and the manifestation of consecutive exotropia is lower than is known from other surgical procedures.      

Feature-based activation and suppression during binocular rivalry

In the past decade, effects of pattern coherence have indicated that perception during binocular rivalry does not result solely from reciprocal inhibitory competition between monocular channels. In this study we were interested in feature selectivity both during dominance and during suppression. The first experiment shows that a suppressed stimulus perceptually appears earlier when it shares features with a visible stimulus than when it does not. Subsequently, our second experiment suggests a reversal of this effect when similarity is exhibited with a suppressed stimulus. These findings hint at a role for both selective enhancing (Experiment 1) and selective inhibitory cortical mechanisms (Experiment 2) in causing image rivalry. From a phenomenological perspective these results suggest that we are not only selectively aware but also selectively unaware of specific features in the visual scene.     

Increasing depth of binocular rivalry suppression along two visual pathways

Binocular rivalry refers to the alternating perception that occurs when the two eyes are presented with incompatible stimuli: one monocular image is seen exclusively for several seconds before disappearing as the other image comes into view. The unseen stimulus is physically present but is not perceived because the sensory signals it elicits are suppressed. The neural site of this binocular rivalry suppression is a source of continuing controversy. We psychophysically tested human subjects, using test probes designed to selectively activate the visual system at a variety of processing stages. The results, which apply to both form and motion judgements, show that the sensitivity loss during suppression increases as the subject's task becomes more sophisticated. We conclude that binocular rivalry suppression is present at a number of stages along two visual cortical pathways, and that suppression deepens as the visual signal progresses along these pathways.     

Orbital rhabdomyosarcoma in childhood

Background: Rhabdomyosarcoma is the most common malignant orbital tumor in children. Treatment modalities (individualized therapy or study protocol) have been changed radically. Surgery was supplemented by radiation therapy and chemotherapy. The objective of our retrospective analysis was to define the prognosis in correlation to changes of treatment in an unselected patient group of a single institution. Patients and methods: Between 1954 and 1995, 18 patients (age at presentation 1 month to 17 years, 11 male and 7 females) with orbital rhabdomyosarcoma were diagnosed and treated at our institution. Results: The 5-year survival rate was 76 %. Primary exenteration was replaced by tumor resection (microsurgery), radiation therapy and chemotherapy. Favorable outcome in the precytostatic era (with permanent loss of function) was not significantly improved by polychemotherapy. Microsurgery seems to increase the risk of recurrence. Conclusion: Considering the high risk of recurrence, primary exenteration in selected patients with expanded primary tumor is still a therapeutic option.      

Causes of secondary glaucoma in Paraguay

Summary Glaucoma is the third-most-frequent cause of blindness in the world, with a total of 5.2 million blind people as a result of this disease; 80 % live in developing countries. In Paraguay, after cataract it is the second-most-frequent-cause. Early detection of the risk factors and groups can help to avoid progress of this disease. Trauma, cataract and infectious uveitis represent special risks for developing secondary glaucoma, which is a more frequent cause of blindness in third-world countries than in industrialized nations. Until now there has been little data regarding the causes, disease course, and options for therapy. Therefore, secondary glaucoma was examined in Paraguay to obtain information on the situation in Latin America. The aim of the study was to explore the causes of secondary glaucoma for programs concerning prevention and therapy. From November 1996 to February 1997 patients with secondary glaucoma were examined at the University Hospital of Asunción, Paraguay. After the clinical examination the secondary glaucomas were classified. Patients with primary glaucoma were included in the same period of time as well in order to get the rate of secondary glaucoma. Altogether 293 patients were examined: 61 with secondary and 232 with primary glaucoma. The causes of secondary glaucoma in 73 eyes were: 20 (27 %) with pseudoexfoliation glaucoma, 19 (26 %) with post-traumatic glaucoma, 16 (22 %) with neovascular glaucoma, 4 (5 %) with lens-related glaucoma, 3 (4 %) with glaucoma associated with ocular surgery, 2 (3 %) with pigmentary and 2 (3 %) with corticoid-induced glaucoma. A ratio of 4:1 primary glaucomas to secondary glaucomas was found. The development of special measures for prevention and early therapy is only possible if the causes of this severe disease are explored. The results of this study represent basic information and could help to introduce of prevention programs.      

Acute hypopyon uveitis in a patient with acquired immunodeficiency syndrome treated for systemic Mycobacterium avium complex (MAC) infection with rifabutin

Background: Hypopyon-uveitis has been identified as a dosage-dependent side effect in patients with acquired immunodeficiency syndrome who are treated for Mycobacterium avium complex (MAC) infection with systemic rifabutin. Patients and methods: We report a 38-year-old female AIDS patient with bilateral hypopyon uveitis under therapy with rifabutin in combination with clarithromycin and indinavir. Results: At the time of presentation of the bilateral hypopyon uveitis the patient was treated with rifabutin (300 mg/day), clarithromycin (1000 mg/day) and ethambutol (1000 mg/day) for an M. avium complex infection. Also, the patient received the protease inhibitor indinavir. The rifabutin dose was reduced to 150 mg/day. Hypopyon and inflammation resolved under therapy with steroids. Conclusions: The concomitant use of rifabutin, clarithromycin, and protease inhibitors may lead to hypopyon uveitis. Reduction of dosage of rifabutin (150 mg/day) and treatment with topical steroids are required.      

Therapy-resistant unilateral chronic blepharokeratoconjunctivitis as the main finding in autoaggression syndrome. Clinicohistopathological findings

Summary Autoaggressive syndromes as causes of diseases underlying chronic blepharitis and keratoconjunctivitis that are refractory to treatment are often difficult to recognize. Patients: Three female patients (age 21, 25, 41 years) and one male patient (age 42 years) had suffered from a right-(4 × ) or left-(1 × ) handed treatment-refractory blepharokeratoconjunctivitis for 1, 2 ,11 and 30 months prior to admission. In each case more than 5 ophthalmologists and 2–6 eye hospitals had been consulted, and extraocular surgery had been performed 1–4 times. Results: Patients presented with a visual acuity of 0.3 p (1 × ), 0.1 (1 × ), FC (1 × ), HM (1 × ). In three patients contact eczema of the facial skin and lids and a corneal pannus were observed; in two patients we saw purulent pseudomembranous and in two patients chronic cicatrizing keratoconjunctivitis. Conjunctival smears grew P. aeruginosa, and S. aureus; impression cytology showed infiltration with neutrophils and epithelial keratinization; histopathology indicated chronic inflammatory, partly purulent subepithelial and stromal conjunctival infiltrate with hyper- and parakeratosis fibrous strands and epithelial cell loss; the lower lids showed parakeratosis, focal necrosis, intercellular edema and a lymphohistiocytic round-cell infiltrate. Furthermore, multiple allergies to antibiotics and preservatives (4 × ), lacerations of the arms and legs (2 × ) and an irritative-toxic dermatitis (1 × ) were substantiated. In the patients who agreed to a psychiatric consultation, somatized-agitated longing for care combined with a dependent and infantile personality (1 × ) and reactive depression (2 × ) were verified. Conclusions: In patients suffering from treatment-refractory unilateral chronic blepharokeratoconjunctivitis correlated with the hand, one must take into consideration the fact that other factors may be involved: possible exacerbation prior to examinations; multiple inpatient diagnostic and surgical procedures in different locations; histopathological mixed inflammatory patterns; and psychiatric syndromes.      

Long-term stability of the heparin surface on PMMA-intraocular lenses – results of an in vitro study

Summary The surface modification of PMMA-intraocular lenses (IOLs) demonstrated a blood-aqueous-barrier protective effect and reduced the incidence of IOL depositions and postoperative fibrin exudation, especially in risk patients (e. g. pediatric cataract, diabetes mellitus, recurrent uveitis). The long-term stability of the surface modification via phenylimines, which permit a covalent surface linkage of heparin to synthetic polymeric materials by reductive amination, is still unknown. Material and methods: Four heparin surface-modified (HSM) monofocal and two unmodified monofocal sterile PMMA-IOLs were stored in an aqueous-serum mixture at 37 °C over a period of 4 years and 1 months with daily rotation. After 4 years the concentration of surface-bound heparin on two HSM-IOLs of this mixture and two brand-new HSM-IOLs were determined using an orcin-assay after initial heparinase treatment. Four years after incubation, the modified toluidine blue staining method was used to examine the surface-bound heparin on synthetic polymers. This staining technique with toluidine blue, a non-protein basic substance, enables examination and analysis of the homogeneity of the mono-molecular heparin layer even under critical conditions because of its homogeneous staining. Light and scanning electron microscopic examination of the IOL surfaces were subsequently performed. Results: The concentration of heparin (μg/cm²) on the IOL surface after 4 years of incubation and treatment with heparinase was valued at 0.51 ± 0.05 and 0.53 ± 0.04 in the two brand-new HSM-IOLs. A slightly coarse-grained complex agglutination on the IOL surface was detected by the toluidine blue staining method. Light and spectral microscopy of the surface of the stained IOLs as well as scanning electron microscopy of all HSM-IOLs showed a homogeneous heparin structure and coating after 4 years of in vitro storage. No signs of desorption or reduced reactivity of the heparin were observed in comparison with new HSM-IOLs. The unmodified PMMA-IOLs did not stain, as expected. Conclusion: The heparin-modified surface of the examined PMMA-IOLs was intact even after 4 years of storage in an aqueous serum solution. A long-term benefit, in addition to the advantages of the hydrophilisation in the immediate postoperative period, especially for risk patients, is therefore suggested.      

Neurophysiological examinations in patients with pituitary surgery

Background: Pituitary tumors are adenomas of a region of the sella turcica which can produce compression of the anterior visual pathway. Patients and methods: Besides clinical signs of visual improvement such as enhanced visual acuity and visual field, the use of electroophthalmological methods can help monitor patients after neurosurgery. Results: The N₇₅ P₁₀₀ amplitude of the p-VEP has proven to be the most sensitive marker for measuring-improvements after surgery. This amplitude significantly increased, whereas latency time, visual acuity and visual field showed no statistically significant changes after surgery. Conclusions: The p-VEP is an important tool in treating patients with compression of the visual pathway.      

The DOG in the Internet. Resources and interest in it

Objective: The German Ophthalmologic Society is rising to the challenges of the information age by offering comprehensive information resources online. Methods: The society's board decided on the development of an Internet website in October 1996. Since February 1997, the website has been available under the Internet address www.dog.org. The amount of information offered has been growing fast during the following 12 months. Results: On its website, the DOG offers information about itself, membership, further education, and a catalog of important addresses, patient information, official recommendations, and the program and abstracts of the annual sessions. The ICD10-aug was integrated into the website as a database application. A discussion group is reserved for ophthalmologists who can use this platform to share ideas and discuss clinical topics. Conclusions: The website of the DOG consists of over 4,900 files that represent the activities of the society. The website's access log indicates steady interest in the information offered. Over 53,000 users visited the DOG website. The discussion group is used by 71 members from 10 countries (all numbers as of 9/98).      

Histamine content in tears in patients with allergic rhinoconjunctivitis

Summary The classic clinical symptoms of allergic conjunctivitis (type I allergy) – itching and lacrimation – are the effect of histamine. Determination of histamine levels in tears may be useful in evaluating the dynamics of local histamine release in connection with the clinical findings. Patients and methods: Between 1. 7. 1994 and 31. 6. 1995 we analyzed the histamine levels in tears and investigated the clinical symptoms (score of 0–3) of 32 hyposensitized pollen-sensitive patients (14 males and 18 females, aged 18–45 years, group I) and of 32 controls (group II) without any allergic disease, performed in each case once in season and once out of season. Tear production and composition were measured by Schirmer's test and tear break-up time at the same time. The histamine levels of the tear samples (obtained by microcapillary method) were analyzed by electrochemical determination. Results: In group I there was a highly significant increase of the mean histamine level from 0.89 ± 2.22 ng/ml (out of season) to 7.71 ± 7.51 ng/ml (in season) for the right eye and from 0.73 ± 2.36 ng/ml (out of season) to 9.51 ± 9.07 ng/ml (in season) for the left eye (P = 0.0000). The histamine level in tears of the controls (group II) was below the detection limit in all samples. The seasonal histamine level were higher with the severity of atopy (Erlangen atopy score). There was no significant influence of age and gender. The reduction of allergic symptoms during hyposensitization was not comparable to the degree of seasonal histamine level. Compared with the clinical findings, the histamine level in tears did not correlate with the symptoms of lacrimation, itching and conjunctival hyperemia. Conclusion: The histamine level in tears alone is not useful as a marker for the clinical severity of this atopyassociated disorder and for the efficacy of the anti-allergic therapy. After standardization of the determination method and the identification of other soluble mediators simultaneously, the histamine level in tears can be used as one part of a profile of mediators to evaluate the clinical symptoms.      

Intraocular pseudotumor in a patient with Aids. Block excision, differential diagnosis, histology

Summary Background: Intraocular pseudotumors are a rare event in Aids patients and often pose diagnostic problems. Case report: A 37-year-old patient who had had HIV seroconversion for 7 years was seen to developed progressively growing, multiple, disseminated, subretinal lesions OD > OS, accompanied by exudative retinal detachment and iritis. Since all etiological laboratory diagnostic efforts to detect an infectious, noninfectious and neoplastic systemic lesion failed, a diagnostic and curative therapeutic chorioretinal excisional biopsy specimen of the largest of the tumors (3 × 3 × 2 mm) was taken. The histological work-up demonstrated granulation tissue similar to an intracular pseudotumor without signs of infection, malignancy or reactive lymphoid hyperplasia. This finding resulted in systemic corticosteroid treatment with complete resolution of the lesions in both eyes and no recurrences. Conclusions: An invasive diagnostic procedure in patients suffering from lesions of unknown cause resulting in the institution of an appropriate medical treatment may be beneficial for the integrity and vision of the respective eye.      

Functional hierarchies of nonconscious visual processing

A number of psychophysical techniques can be used to eliminate the registration of stimuli in visual awareness and to study the dynamics of conscious and nonconscious information processing in the visual system. However, little is known about how these techniques relate to each other. We chose to compare binocular rivalry, induced by orthogonal gratings presented separately to the two eyes, and metacontrast suppression, produced when a target stimulus is followed by a spatially surrounding mask stimulus, to investigate relative levels and correlates of nonconscious processing. Combined with prior results, our findings indicate that binocular rivalry expresses its suppressive effects prior to the level at which the mechanism of metacontrast does. Implications for theories of masking and interpretations of the loss or perceptual effects when stimulus visibility is suppressed by different psychophysical methods are discussed.     

The effects of changed biomechanical parameters on measurements of intraocular pressure in keratoconus patients

Background: Keratoconus is associated with changes in the corneal structure, such as defects of Bowman's layer, a decrease of corneal thickness etc. They result in alterations of some of the biomechanical parameters of the cornea, namely, rigidity and elasticity. The present study was performed to examine how impression tonometry and applanation tonometry for determination of intraocular pressure (IOP) are affected by the changed biomechanical parameters associated with keratoconus. Patients and methods: We examined 20 normal subjects (40 eyes) and 17 keratoconus patients (25 eyes). The corneal thickness was measured by ultrasound pachymetry in the corneal center. In the keratoconus patients, an additional measurement was made at the conus peak. The corneal curvature was determined using the TMS keratoscope. The IOP measurements were made with the Schi?tz tonometer (10 g). For comparison, additional IOP measurements in the corneal center and, in the keratoconus group, on the conus peak were made with the applanation tonometer. Results: The normal subjects had a central corneal thickness of 548 ± 30 μm, compared to 505 ± 42 μm in the corneal center and 425 ± 41 μm on the conus peak in keratoconus patients. The average corneal curvature was 43.3 ± 1.8 D in the normal subjects and 47.8 ± 4.1 D in keratoconus patients. Applanation tonometry produced results on 11.33 ± 1.43 mm Hg in the normal group (corneal center) compared to values of 12.00 ± 2.55 mm Hg (corneal center) and 7.30 ± 1.95 mm Hg (conus peak) in the keratoconus cohort. The coefficient of rigidity was 0.0236 ± 0.0026 μl⁻¹ in the normal subjects, compared to 0.0173 ± 0.0050 μl⁻¹ in the keratoconus patients. Conclusion: The morphological changes associated with keratoconus may cause tonometry errors.      

Gene transfer in ophthalmology

Background: Research into the molecular and genetic basis of disease is continually expanding. How does the increasing knowledge about the genetic basis of eye diseases contribute to the development of new therapeutic strategies? Materials and methods: Gene therapy, here defined as the introduction of genetic material into human cells, offers great opportunities. Gene transfer strategies can be used for gene replacement in recessive disease, gene inactivation in dominant disease, expression of “rescue factors” and apoptosis modulators in degenerative disease, “suicide genes” for example in proliferative diseases and expression of immunmodulatory factors in immunological disorders. Viral vector systems have been developed to introduce the gene of interest into the target cell. Results: Most of the published strategies include the use of vectors for gene transfer. Adenovirus (AV), adenoassociated virus (AAV), encapsulated adenovirus mini-chromosomes (EAMs), herpes simplex virus (HSV) and lentiviruses are the most frequently used viral vector systems to date. Their advantages and disadvantages, the in vivo models used for gene transfer in retinal degeneration, and the results obtained to date by different research groups in the field will be reviewed. Conclusions: Gene transfer into ocular tissues has been demonstrated with growing functional success and may develop into a new therapeutic tool for clinical ophthalmology.      

Intraoperative and postoperative complications after laser in situ keratomileusis (LASIK)

Purpose: To quantify the incidence and type of complications after LASIK for the correction of myopia with special consideration to the time lapse after surgery and the possible consequences regarding high-contrast sensitivity and other modalities of visual acuity. Material and methods: Between January 1995 and April 1997, 125 eyes of 88 patients with myopia greater than −6.0 D who could not wear contact lenses were operated on at our institute. In this prospective study the patients were examined consecutively preoperatively as well as postoperatively at day 4 and months 1, 3 and 6. The complications were divided into three groups (intraoperative, early postoperative and late postoperative). Results: Our complication rate was 7.2 % (loss of 2 lines of visual acuity) – with cutting artifacts related to the microkeratome, wrinkling of the flap and epthelial ingrowth. Conclusions: LASIK is a microsurgical procedure that requires adequate experience and the desire by the surgeon for self-evaluation. In spite of the good clinical results in the correction of high myopia the complication rates seems still to be too high. This should be the objective for further improvement primarily related to the microkeratomes.      

Contact lens intolerance in infantile aphakia – indication for intraocular lenses?

Summary Due to the low rate of complications, lentectomy and contact lens fitting is the standard treatment for congenital cataract. However, contact lens fitting is not possible in all children. The authors report the main reasons for discontinuation of contact lenses in their patients. Method: In 134 consecutive lentectomies of 90 children, the underlying eye diseases and general diseases, the age at operation, compliance of parents and children, and social background were analyzed. Results: Twenty of the 90 children had to discontinue contact lens wearing. Twelve of these children were operated on one eye and 8 on both eyes. Only 2 children showed signs of contact lens complications. In 2 children treatment was stopped because of the poor visual prognosis and in 10 children the parents discontinued contact lens treatment because of a severe handicap of the child (n = 2) or due to misunderstanding and parental noncompliance (n = 8). Six children refused contact lenses without obvious reasons. Among the latter, children 2–4 years of age were at the greatest risk. Children with additional systemic abnormalities frequently developed contact lens intolerance. Conclusion: In children with systemic abnormalities and in the case of parental communication and compliance problems, discontinuation of contact lenses has to be expected in up to 30 % of cases. In these children and in children who object to contact lenses at the age of 2–4 years, intraocular lens implantation should be considered, especially in unilateral cataract, if successful contact lens treatment is not achievable within 8–12 weeks.