It was my good fortune, during the course of my college years, to spend two summers studying invertebrate zoology at the Cold Spring Harbor Biological Laboratory in Long Island, New York.
We swept the bushes with our nets and chased flying insects, especially moths and butterflies. We examined and studied each insect macroscopically and microscopically. In addition, we studied the animal life of the sea, rivers, and those on and in the ground.
During the course of these observations I found myself fascinated by the eyes of these numerous and diverse creatures, some of whose eyes I thought at that time functioned better than human eyes.
All insects had compound eyes, looking much like honeycombs when viewed through a microscope. The ordinary housefly (musca domestica) has 4000 of these minute eyes while the dragonfly (libellula) may have as many as 20,000 such eyes. Many insects such as the grasshopper have several single simple eyes as well.
Some insects, including the housefly, the dragonfly, and the damselfly can see up and down and back and forth at the same time- what human being can even compete with this feat?
But one group of animals have, in my estimation, the strangest eyes of all. These are the garden snails and slugs. Each has two "horns" which are really stalks bearing an eye at the end. They can extend their eyes forward or retract them back into their bodies. But that is not all - a crayfish can do that. Snails and slugs walking on a leaf can, at the edge, curve one or both stalks underneath and see what is on the other side.
However, in spite of all of these ocular acrobatics, no invertebrate has vision comparable to that of man. Careful studies of the vision of invertebrates have been made.
Most sighted animals are unable to live without vision. In the human being vision is the most important need in emotional development and for an understanding of one's environment. The child with congenital blindness has an extreme handicap. A quick diagnosis by the pediatrician and immediate referral to an ophthalmologist for treatment may save that child a life of deprivation and unhappiness.
Some years ago, when the relationship between rubella and infantile cataracts was first discovered, a very experienced ophthalmologist, skillful at cataract surgery, called me. As I noted in a previous issue of Pediatric Annals, a five to six-month-old infant with rubella cataracts was being brought to New York for removal of the cloudy lenses. Would 1 take over the medical care of the child?
This was an operation practically unheard of in those days on a child so young. It was generally claimed that after such surgery, the eyes would not develop in size, but this had not been proven.
I agreed to follow the child with the hope of restoring vision before it was too late. The operation was performed with ease and the tiny lenses sent to the rubella laboratory in New York City.
The eyes healed normally and the infant started to follow light. A short time later the mother was shown how to apply contact lenses to the child's eyes. She quickly learned the procedure. The baby definitely began to follow objects. However, the neurological development was very slow, and we soon realized that the child was mentally retarded - a common complication of congenital rubella, one not well recognized at the time of this operation.
I note, however, that in the article on Infantile Cataracts in this issue of Pediatric Annals, the author, Dr. David A. Hiles, advises that infants born with dense or complete bilateral cataracts or even dense mild cataracts should have surgery within the first week of life.
The important fact, which should be considered by all pediatricians is that, if a heavy cataract does exist, amblyopia may result, even within a few weeks. And, as with the case previously mentioned, parents can easily be taught to apply contact lenses. The use of implanted intraocular lenses in infants and small children is still under study with long-term results unknown.
This, the second segment of the symposium, is again under the Guest Editorship of Dr. J. Denis Catalano, Chief of the Department of Pediatric Ophthalmology at the St. Louis Eye Hospital in St. Louis, Missouri.
Dr. Catalano has chosen to include in this issue of the journal three inter-related subjects - strabismus, infantile cataracts and amblyopia. The final article is on neuroophthalmology. The first paper covering "Strabismus" has been written by Dr. Catalano. 1 am sure that all practicing pediatricians would agree that, with the exception of eye trauma, this is the most common ophthalmological abnormality encountered in young children.
In most instances the observation comes from the parents. The child should be seen promptly by the pediatrician for examination and referred if necessary. As Dr. Catalano notes at the outset of his article, "It is never correct to wait and see if the child outgrows the misalignment."
Following this statement, all the various types of strabismus are defined with the mechanism and etiology described. It is most important to ascertain the vision status of the child and to make every effort to prevent or minimize amblyopia before it is too late.
The discussion contains many interesting and important facts. A few that stand out in my mind are: 1) in the vast majority of patients with strabismus the eye muscles are normal in structure and function, 2) approximately 50% of all children with strabismus have positive family histories, 3) infants can develop amblyopia in as little time as one week, and 4) eye exercises have proven a failure in obtaining effective and long-term results.
The second contribution to this symposium discusses "Infantile Cataracts"and has been authored by Dr. David A. Hiles, Clinical Professor of Ophthalmology of the University of Pittsburgh School of Medicine.
When one considers the importance of vision to infants in relation to their parents and their environment, it is clearly important that corneal opacities be discovered and treated as soon as possible. This places the importance of discovery and referral completely on the shoulders of the first examining pediatrician. The urgency is impressed when we realize that amblyopia may occur within one week.
Some years ago I attended a conference on infant eyes conducted by the late Dr. John M. McLean who at that time was Professor of Ophthalmology at Cornell University Medical College. In the course of the conference Dr. McLean remarked that every pediatrician owed it to every newborn to examine the eyes with an ophthalmoscope. I asked him if he knew any pediatrician who carried this out and he mentioned one. I contacted this pediatrician and he denied doing this except in very rare cases where there were specific indications. I also called many of the pediatricians in New York City and none made this a part of their routine examination.
I mention this because I also note in Dr. Hiles' article his emphasis that "an ocular examination, including fundoscopy, should be performed on all babies before they are discharged from the newborn nursery."
With our present knowledge of treatment of infantile cataracts, the detection in the newborn nursery becomes most urgent.
In this excellent and complete article Dr. Hiles presents not only etiological factors and diagnostic features but the surgical care and the post-surgical aids to the child's vision.
The third paper, which follows logically from the previous two, is entitled "Amblyopia and the Pediatrician." It is written by Dr. David R. Stager, Director of the Ophthalmology Service at the Children's Medical Center, Dallas, Texas, and Associate Clinical Professor of Ophthalmology, Southwestern Medical School.
Once again emphasis is placed on "the determination of the presence or absence of amblyopia as the most important aspect of the routine eye examination of the pediatric patient."
In this well-illustrated article Dr. Stager differentiates between the organic and functional causes of this visual difficulty. The organic causes such as that of chorioretinitis or optic atrophy are permanent and irreversible, the functional causes are numerous. Here however the retina and visual pathways appear normal but vision is hindered by such conditions as cataracts, corneal scarring or acquired strabismus.
The duration of the amblyopia determines how reversible the functional disturbance will be. The various types of amblyopia are classified and discussed individually with the means of diagnosis and the methods of treatment.
The final contribution is titled "Neuro-ophthalmology for the Pediatrician" by Dr. John E. Keltner, Chairman of the Department of Ophthalmology, and Professor of Ophthalmology, Neurology and Neurological Surgery, University of California Davis Medical Center.
In this excellent and interesting article Dr. Keltner instructs pediatricians on specific techniques in examining children to determine if what appears to bea vision defect warrants neurological or ophthalmological care. Special tests are described to test visual fields, ocular motor function, visual acuity, pupillary reaction, and ocular motor disorders such as nystagmus and strabismus. As with the previous article this paper is beautifully illustrated with many clear and informative photographs.
The author emphasizes the importance of obtaining a good medical and family history. He divides the age periods for visual acuity and general ocular examination into three areas: infancy to one year of age, one to three years of age, and over three years of age.