ADMINISTRATIVE UPDATE

This issue of the Newsletter will review the results of our survey on pediatric corneal transplants. It will also summarize some recent scientific articles of interest to the members of our association, and present a case study for discussion.

The last meeting of the PKA study group was held at ARVO in Sarasota, Florida in May, 1994. Attendees at that meeting included Drs. Peter Laibson and his fellows, James Flowsey, Gerald Zaidman, Lance Forstot, Alan Sugar, Barbara Grenell and Mohamad-Reza Dana. We will continue to hold two breakfast/luncheon meetings a year. One will be at the American Academy of Ophthalmology and the other at ARVO. At each meeting a clinical topic of interest to the members of the group will be presented along with a summary of previous mail responses to that topic from members.

The PKA is now incorporated as a tax exempt organization and has a set of bylaws. All contributions are tax free but dues to the organization from its members can be considered a business expense.

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SURVEY RESULTS

The last Newsletter included survey forms regarding the pre- and post-operative management of infants and children with corneal opacities. Certain clinical practice patterns were observed in the responses.

Regarding the initial pre-operative evaluation, all of the respondents would attempt an office visit consisting of a penlight exam, slit lamp exam, tonometry and funduscopy. Two-thirds of the respondents would then perform ultrasound. About 75% of the respondents routinely perform an exam under anesthesia after the office exam, some as soon as possible. The other 25% generally do not perform an EUA. Twenty percent of the respondents simultaneously have a pediatric ophthalmologist check the patient.

Most respondents were relatively aggressive regarding the timing of surgery. Nearly 70% would perform a penetrating keratoplasty on unilateral opacities soon after the diagnosis was made. Nearly 90% would do urgent surgery on bilateral cases. The 10% that wouldn't perform rapid surgery on bilateral cases felt that surgery would be easier on slightly older children. They also felt that since unilateral amblyopia is less of a concern in bilateral cases, surgery could be delayed.

In general, the post-operative regimen consisted of many months (6-12) of topical corticosteroids, supplemented by occasional periocular steroids. The preferred treatment for glaucoma consisted of topical agents only, usually a beta blocker. A significant minority used oral agents (DIAMOXIS) only. The intraocular pressure is usually checked in the office without sedation using either a Perkins tonometer, tonopen, or pneumotonometer. (The next Newsletter will concentrate on this topic.)

Visits are usually daily for the first 7-21 days. This frequency is extremely dependent on the presence or absence of sutures. In general, patients are examined very often until all sutures are out. The frequency of visits is then decreased. Once sutures are out, visits usually become more routine, occurring once every week or two and quickly being decreased to monthly, etc.

Suture removal is relatively independent of the diagnosis but is relatively dependent on the age of the recipient. In infants (patients less than one year of age), about half of the respondents removed sutures in less than one month, while the other half removed them in 1-3 months. In older children (up to six years of age), all sutures were usually out 3-6 months after surgery (half the respondents removing them closer to three months and the other half closer to five months).

Children over the age of 6-8 have sutures removed similar to adults.

To summarize, the usual approach to a pre-verbal child with corneal opacities is an office visit followed by an EUA generally leading to rather rapid surgery. Afterwards, close monitoring of the child with early suture removal is performed.

I would like to thank the members of the PKA for their excellent responses.

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RECENT ARTICLES AND PRESENTATIONS

ARVO, May 1994
L.L.H. Yang and associates from Atlanta presented a series of corneal transplants in infants and children with Peter's anomaly. This was a retrospective series of 11 children who underwent penetrating keratoplasty between 1977 and 1981. These 11 children required 44 PKPs in 18 eyes and they were followed an average of eight years post- operatively. Nine of the 18 eyes underwent one transplant; four eyes 2-3 transplants; five eyes four or more transplants. Nine eyes eventually required surgery for glaucoma. A lensectomy was performed on 11 of the 18 eyes. At one year, 67% of the grafts remained clear; at five years, 55% of the grafts remain clear. Of the 11 eyes with clear grafts, nine eyes had vision better or equal to 20/400. During the discussion period, the authors commented that eyes that did not have a lensectomy or vitrectomy did better than eyes that required ft. The presence of glaucoma pre-operatively predisposed to poor graft survival. The authors did not report on their incidence of disastrous complications (i.e., phisthis, retinal detachment, etc.).

ARVO, May 1994
Robert L. Pfeiffer and colleagues from the University of North Carolina presented a paper on TGF alpha and ocular development. They found that TGF alpha deficient mice displayed eye abnormalities of varying severity including anterior segment dysgenesis as well as lens, retinal and eyelid defects.

World Corneal Congress, Toronto, June 1994
Dr. S.K. Rao and colleagues presented a retrospective study of 48 penetrating keratoplasties performed on 45 infants and children. The patients were divided into three groups: congenital corneal opacities, acquired non-traumatic opacities, and acquired traumatic opacities. The most significant conclusion was that the acquired non-traumatic corneal opacities, (i.e., corneal ulcers, keratoconus, herpes keratitis, etc.), had an 80% graft survival at one year. The two other groups had a 50% graft survival at one year. Children under the age of 4 had a 57% rejection rate while over the age of 4 had a rejection rate of approximately 8-16%.

Ophthalmic Surgery, May 1994
Drs. Mark Milner, Jeffery Liebmann and associates reported on "Ultrasound biomicroscopy of the anterior segment in patients with dense corneal scars". Ultrasound biomicroscopy (UBM) uses high resolution ultrasound waves to provide visualization of the anterior segment. It is particularly helpful in patents with dense corneal opacities. Using UBM, the authors were able to visualize the ids, lens, angle, ciliary body and cornea. They were able to measure corneal thickness, determine the presence or absence of iridocorneal adhesions, peripheral anterior synechiae, and cyclitic membranes.

American Journal of Ophthalmology, April 1994
Dr. Vajpayee and associates reported on "Combined keratoplasty cataract extraction and intraocular lens implantation, after corneal-lenticular laceration in children". The authors discuss the need for rapid visual rehabilitation in children with eye injuries because of the risks of amblyopia. Therefore, they took an aggressive approach to children who suffered concurrent traumatic cataracts and centrally located corneal lacerations. Six of their seven patients were nine or younger. Surgery was performed 11/2 to six months after the initial repair of the corneal injury All the patients had pre-op visual acuity of hand motion or less. Each patient underwent keratoplasty combined with cataract extraction and insertion of intraocular lens. In each patient, the surgeons were able to implant a C-loop posterior chamber intraocular lens. Interrupted sutures were used and the sutures were removed early. The post-operative vision, after a follow-up 9-36 months, ranged from 20/40 to 20/200. This may be a valuable procedure in this small, selected group of children.

Ophthalmic Surgery, June 1994
Michael R Vrabec and associates from the University of Vermont presented "Lamellar keratoplasty performed with a corneal scleral button". This article presents an interesting technique that was used to remove a limbal dermoid from a 26-month-old child. A lamellar graft was created from a comeo-scleral button. This lamellar button was then used to close the defect that remained after the dermoid was removed. In this case, surgery did not lead to significant astigmatism or scarring through the pupillary axis.

American Journal of Ophthalmology, January 1994
Thomas Clinch and associates from LSU and Wills Eye Hospital reported on "Microbial keratitis in children". The authors retrospectively identified 29 cases of non viral microbial keratitis in children. The children ranged in age from five months to 16 years. Fifty-five percent of the organisms isolated were gram positives; 21 % were gram negative; 17% were fungal. The most common risk factor for infectious keratitis was trauma, followed by severe systemic illness, contact lens wear, exposure keratitis, or ocular surgery. Most of the trauma occurred in boys with sports-related injuries or while playing with sticks. The systemic illnesses included broncho-pulmonary dysplasia, neurofibromatosis, hydrocephalus or mental retardation. The authors believe that risk factors for infectious keratitis in children are similar to those in adults except for the category of severe systemic illnesses, especially when children require mechanical ventilation.

Ophthalmic Surgery, January 1993
Vernon C. Parmley and associates presented on "Peter's Anomaly, A review of 26 penetrating keratoplasties in infants". The authors presented an interesting study of 26 grafts on 16 eyes in 10 infants with Peter's anomaly. The authors used interrupted 10-0 nylon sutures. Post-operatively, relatively frequent topical corticosteroids were used. An exam under anesthesia was performed quite often until all the interrupted sutures were removed (usually between 2-8 weeks after surgery). Eight patients had bilateral Peter's anomaly. Six eyes were grafted two or more times. Only one eye required lensectomy at the time of first keratoplasty. Nine eyes did subsequently require cataract surgery. Of the eyes requiring later cataract surgery, six required regrafting because of graft clouding. Glaucoma was the most common complication and it was present in five of the patients pre-operatively and 15 of the patients post-operatively. Ten of the eyes required surgical procedures to control intraocular pressure (either cyclocryotherapy or molteno implants).

This study is different from previous studies in the high incidence of glaucoma and graft failure. The authors speculate that frequent cyclocryotherapy may have accounted for the high incidence of graft failure. They propose that glaucoma procedures done prior to keratoplasty may decrease the need for cyclocryoblation and may increase the incidence of successful and clear corneal transplants.

Investigative Ophthalmology, December 1993
Eileen Birch and associates presented "Outcome after very early treatment of dense congenital unilateral cataract". The authors wanted to determine whether very early treatment for congenital cataract results in better long-term functional outcome. Vision was measured by forced choice grating acuity and contrast sensitivity. Eight eyes underwent cataract surgery and contact lens fitting by six weeks of age, while six eyes underwent treatment between 2-8 months of age. The results seem to favor very early treatment since it appeared that very early treatment (before six weeks) maximizes the potential for visual developmental in the operated eye.

AA0, Chicago, November 1993
Annette Bacon and associates from Moorfields Eye Hospital, London, presented on "Infant donor cornea material for penetrating keratoplasty'. The discussant was Gerald W. Zaidman, New York Medical College. The authors investigated the feasibility of using infant donor corneal tissue for adult corneal transplants. The hope was that infant corneal tissue would lead to a "natural myopia" that might correct the residual hyperopia present after aphasic corneal transplant surgery. Additional possible advantages was that infant tissue might heal more quickly than adult donors and that the high endothelial cell count of the infant cornea might lead to greater graft survival. However, the use of infant corneal donor tissue presents many problems. Most importantly is an unpredictable refractive result. Additionally, the authors found that 53% of the patients had a rejection episode. In summary, the authors and the discussant agree that the use of infant donor material for penetrating keratoplasty is unpredictable and risky and should be reserved for an emergency basis.

The next few articles are older, but I have found them quite valuable.

The first is by Susan Tucker and associates entitled "Corneal diameter, axial length and intraocular pressure in premature infants" from the August 1992 issue of Ophthalmology. In this paper, 70 premature infants, 25-37 weeks post conception, were examined to determine the correlation of corneal diameters, axial length and intraocular pressure with gestational age and birth weight. The article presents an age- and weight-related range of corneal diameters and axial lengths. The authors' data will aid the ophthalmologist in assessing ocular dimensions in premature infants.

A similar article is one by Maria Musarella and Donald Morin from Toronto, Ontario on "Anterior segment and intraocular pressure measurements of the unanesthetized premature infant" from Metabolic, Pediatric & Systemic Ophthalmology in August 1985.

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PEDIATRIC KERATOPLASTY ASSOCIATION CASE REPORT

The patient was first examined at 9 days of age. He was a healthy, white male, born to a healthy mother after an uneventful pregnancy and delivery. On office examination, the patient avoided light equally with each eye. An exam under anesthesia revealed a small coloboma in the right upper lid. The right cornea had a large dermoid which was 61/2 mm in size, coming from the temporal margin. Part of the dermoid could be lifted up from the cornea. At the nasal edge of the dermoid, there was a partially vascularized dense corneal stromal opacity. The combination of the dermoid and the corneal opacity covered 80% of the undilated pupillary axis. The corneal diameter was normal in each eye. Intraocular pressure was 20 mm OU. No red reflex was noted with retinoscopy in the right eye. The angle structures that could be visualized around the edge of the dermoid appeared normal. The right pupil dilated well, the lens was clear and the fundus was normal. After dilation, a good retinoscopic reflex was present. The refractive error measured approximately +2.00 +2.00 x 90. The patient's left eye was normal.

How would you manage this patient's right eye? Is surgery indicated? How rapidly should surgery be performed? Should atropinization of the right pupil along with patching of the left eye be performed prior to surgery? What type of surgical procedure would you suggest? If vision decreased in the right eye (after patching OS), what would you do?

Please send your ideas regarding the management of this patient to:

Dr. Gerald W. Zaidman
Pediatric Keratoplasty Association
c/o Department of Ophthalmology
Westchester County Medical Center
Valhalla, NY 10595

The next issue of the Newsletter will discuss your responses to the management of the case.

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