DISCUSSION Aphakia is acondition of eye where there is no crystalline lens in which in this case isdue to congenital cataracts. It makes the patient to experience a loss ofaccommodation and thus exhibit a condition of far sightedness. However, afterthe cataract surgery there was absence of history information whether the patientwas corrected with any aphakic spectacle or contact lenses.
But there was nopossibility that this patient was corrected with Intraocular Lens (IOL),because it is impossible for congenital cataracts cases to be implanted with IOLat age less than 6 months. For example in this case of 3 months old baby, IOLpower of about 28-30 D may be necessary for emmetropia and would cause significantmyopia in later life if it was implanted because infants experience largemyopic shifts due to axial growth and rapid eye changes. The major myopicprogression occurred during the first 1 year. Therefore, aphakic patient mayneed either contact lens or spectacle at younger age because it is easier tochange power of their eye soon instead of IOL.
Moreover,although the patient had cataract surgery during early infancy the patientstill encountered visual impairment which is his best corrected visual acuitywas decreased at both distance and near. Visual development has been shown tobe severely affected by visual deprivation. Most people develop low vision as a consequence ofeye conditions and diseases. So in this case this patient is aphakic. Aphakia cause the eye to unable maintain its focuson an object as that object moves closer or farther away due to loss ofaccommodation. Therefore, it is best for the patient to use a hand-held magnifier andother low vision device instead of large printed books while reading because he can also perform other task too usingthat magnifier. This patient also been referred to contact lens clinic. Afterfit with contact lenses, however the improvement were not measurable on Snellenacuity, but the patient himself aware ofthe significant improvement which were measureable through the increase inperipheral awareness compared to the high plus and thick spectacle lenses .
Themagnification factor is very low with contact lenses and there is also nospherical aberration and the visual field is full. From the findings, it can beseen that the power for CL is higher than the refractive power. It is because whenlens dehydration occurs on the eye, lenses may reduce several dioptres of pluspower. Therefore, it is necessary for aphakic lens to be made in an evenhigher plus power to allow for this power reduction to occur on the eye. In this case, thepatient has microcornea and also irregular appearance of cornea (superiorlylocated bleb) which is likely due to the surgeries before.
So that, O2Optix custom lenses were chosen because of its smaller diameter and also higher range of sphere power which rangingfrom +20.00 D to -20.00 D. However, inpediatric aphakia, there is a thick central portion of high plus power lenses whichinherently reduced oxygen permeability and therefore resulting in severalcorneal and conjunctival complications.
These lenses might be damaging to the globeof paediatric patient that is small and still developing. Therefore, hard lenses(RGP) can be among the excellent choices for treatment of pediatric aphakia.Due to paediatric ocular condition which consists of small corneal diameter, anarrow lid fissure with tense lids, RGP lenses could be the best option. RGPlenses are the healthiest lens for the small developing eye when compared withother types of contact lenses.
It requires daily care which is simpler thanother types of contact lens and thus providing great convenience for parents tohandle their aphakic child. However the major problems of wearing any types ofcontact lenses are poor compliance with continual use. The patient developed aphakic glaucoma at1-year-old and the patient had trabeculectomies for both eyes at 6 years of age.Even after the surgery, the patient is still taking glaucoma medication and itis also recommended for him to haveseveral evaluations for glaucoma to monitor any possible progression. It isimportant because when the medical therapy unable to make the patient’s IOP lowersufficiently, the patient is required to undergo another surgical intervention.