PENETRATING KERATOPLASTY AND IOLS

This edition of the newsletter will report (1) the final results of our survey on Penetrating Keratoplasty and Intraocular Lenses in Children; (2) a review of some interesting and pertinent articles that I have culled from the ophthalmology literature since the lost newsletter; and (3) a new case report.

As you may recall the PKA has been collecting data on children who needed a corneal transplant combined with cataract extraction and IOL. The summary of our data follows, I would like to thank the members of the PKA for their help in this endeavor.

We wanted to evaluate the outcome and long-term visual result of intraocular lens (IOL) implantation in children with penetrating keratoplasty (PKP). 150 members of the Pediatric Keratoplasty Association were surveyed to gather data on preoperative diagnosis, axial length, keratometry, calculation of IOL power, style and type of IOL implanted, surgical technique performed (including management of the posterior capsule), graft clarity, and pre- and postoperative visual acuity in children with PKP and IOL implant. 9 cases of children aged 7 years and younger who underwent PKP and IOL implantation between 1992 and 1997 were identified. 5 patients had sustained corneal and lenticular trauma and 4 had congenital disorders that led to a corneal opacity and cataract. Follow-up time ranged from 4 to 62 months. In each patient an A-scan was obtained from either eye. Most surgeons used their "historical K's" for lens calculations and used the SRK II formula. The 5 patients with ocular trauma had improved visual acuity and clear grafts. In each of these 5 patients, the final spherical refraction was within 3.5 diopters of plano with 2-5 diopters of cylinder. Visual acuity of patients with congenital disorders did not improve. Graft failure and severe uveitis requiring graft replacement and IOL removal occurred in 3 of the 4 patients with congenital disorders.

We can conclude that IOL implantation in children with PKP who have sustained corneal and lenticular trauma appears to be safe and effective. Despite their young age and difficulty in determining IOL power, visual rehabilitation was achieved in these 5 patients with refractions approaching emmetropia. However, in children with congenital disorders the results were more problematic and less predictable.

As a result of this data I now feel that IOLs should probably not be used after PKP in children with congenital corneal opacities and cataracts. It can be safely used in children with trauma with good visual and refractive results.

A manuscript based on this data has recently been submitted to Ophthalmology for publication.

PERTINENT ARTICLES:

Oversized grafts in children. Vaipayee et al., Ophthalmology, volume 106, page 829-832, 1999. This article deals with a series of forty patients, twelve years of age and younger who came from three centers, New Delhi, India; Burlington, Vermont; and Melbourne, Australia. The authors decided to oversize the corneal grafts in children by 1.0mm. This was done to avoid post-operative irido-corneal adhesions shallowing of the anterior chamber and secondary glaucoma. They hoped to increase the morphologic success of corneal grafting in their series of children. In their study they found that the oversized corneal grafts did provide good post-operative anterior chamber depth and a very low incidence of secondary glaucoma. They also found that clear grafts were achieved in 85% of the patients at one year (despite the fact that nearly 23% of the grafts suffered episodes of immunologic graft rejection). They obtained moderate amounts of post-operative astigmatism (ranging from 1 to 6 diopters). An unusual aspect of this paper is that corneal ulcers and trauma accounted for nearly half of the cases of corneal opacification. Presumably this represents the experience of the authors in India. In this paper, congenital corneal opacities excluding congenital glaucoma made up approximately 35% of the patients (the experience in the United States is usually the reverse). The children with acquired corneal opacities had more clear grafts and better vision.

Corneal transplantation in young children with CHED. Schaumberg, et al. American Journal of Ophthalmology, volume 127, pages 373-378, 1999. This is the most recent in a series of well written papers from the multi-center pediatric keratoplasty study group involving ophthalmologists from the University of Minnesota, Wills Eye Hospital, the University of Michigan, the University of Illinois and the Harvard Medical School. This paper was a retrospective analysis of children under twelve years of age who underwent penetrating keratoplasty over the last twenty-five years for CHED. The authors found nine patients that qualified for this study. The nine patients had 21 transplants performed on sixteen eyes. The age of the first keratoplasty ranged from three months to ten years. Over the course of the study approximately 70% of the grafts remained clear. Of the four grafts that failed, two failed because of graft rejection and two because of corneal ulcers. Despite the generally good anatomic results post-operative visual acuity improvement was difficult to measure because of the young age of many patients. In addition, some of the patients had their first keratoplasty performed after nystagmus had been noted. In these patients had surgery been successful the eyes presumably would have been amblyopic.

Long-term results of corneal graft survival in infants and children with Peters' anomaly. Yang et al. Ophthamology, volume 106, pages 833-848, 1999 (and discussion following the paper). The authors present data on all the children twelve years of age and younger who underwent penetrating kertoplasty for Peters' anomaly between January 1971 and December 1992. The study is from Emory University in Atlanta, Georgia. They found forty-seven patients who had 144 transplants performed in seventy-two eyes. They reported an overall ten year probability of maintaining a clear graft as only 35%. This poor result is quite different from data presented at the AAO by Dana, et al in 1996. Detailed analysis of the data in this paper provided different findings. The authors found that the eyes that did worst were those with more diffuse and more severe disease. In those eyes (probably Peters' type 11) the long-term graft clarity was 22%. However, in Peters' type I eyes there is a long-term graft clarity ranging from 48 to 67%. Essentially the author's data confirmed the existence of the two groups of patients with Peters' anomaly and they provided valuable information regarding the management of infants with Peters' anomaly. Finally, they found, as have others, that compliance is a very important variable and that patients in poorly compliant social situations were 9 times more likely to have graft failure than patients with good compliance.

Transplantation of congenitally opaque corneas from eyes with exaggerated buphthalmos. FruchtPery, et al. American Journal of Ophthalmology, volume 107, pages 655-658, 1989. I first came across this article in 1998. The authors presented three eyes with congenital corneal opacities, marked buphthalmos and congenital glaucoma. In each, patient cyclocryotherapy was initially performed. The intraocular pressure decreased and the eye became less buphthalamic. Corneal transplant surgery was then performed in each eye. The authors concluded that by lowering intraocular pressure the elasticity of the sclera allowed the globe to decrease in size making surgery easier. They also implied that the eyes that were generally considered hopeless (corneal opacities in bupthalmic eyes with glaucoma) might be amenable to surgical repair.

 Corneal transplantation in infants, children and young adults; Experience of the Toronto Hospital for Sick Children 1979-1988. Erlich, et al. Canadian Journal of Ophthalmology, volume 26, pages 206-210, 1991. Another good article that I recently came across. The authors report their experience with 85 penetrating keratoplasties performed in fifty-four children between the ages of one month and eighteen years from 1979 to 1988. Twenty-seven eyes developed clear grafts; seven of sixteen with Peters anomaly, twelve of seventeen with trauma, six of eight with corneal dystrophy, but only two of five with herpes keratitis and none of eight with congenital glaucoma. This paper is a nice review of the authors experience with a varying group of children with a diverse group of corneal disorders. They also go into detail regarding their peri-operative and post-operative management. They obtained the best results in children with trauma and obtained reasonable results in children with Peters anomaly and corneal dystrophy. Because of the young age of the patients visual acuity could only be measured in a minority of the patients. The authors also reported on their most serious complications. One eye developed an expulsive hemorrhage, one eye had a retinal detachment and four eyes became phthisical. This is an incidence of approximately 10% of severe post-keratoplasty complications that can result in the loss of an eye.

Ultrasound bio-microscopy and histopathology of sclerocornea. Kim, et al. Cornea, volume 17, pages 443-445, 1998. The article was interesting because it demonstrates the utility of obtaining ultrasound bio-microscopy (UBM) in children with congenital corneal opacities.

Is Perception of Light Useful to the Blind Patient. An editorial published in Archives of Ophthalmology, volume 116, pages 236-237, 1998. The writer of the editorial (Dr. Robin D. Ross) notes that a vision of 5/200 is traditionally felt to be the lower limit of vision needed for ambulation. Dr. Ross states, however, that in a recent study of children with retinopathy of prematurity, children with vision less than 5/200 were able to ambulate in strange environments using visual clues. The authors of that study suggested that children may value any residual vision and use their limited vision better than we have been able to measure. The author then surveyed a group of patients at the Rochester Leader Dog School in Rochester, Michigan about the usefulness, if any, of light perception vision. Dr. Ross found that all thirty-two patients felt that light perception vision had been valuable. Almost 80% of them felt that light perception had been useful for mobility and orientation; nearly 70% had noted sleep disturbances since losing light perception vision (this study was of a group of previously sighted adults who had lost light perception vision). The author therefore stresses that with proper mobility training patients may find light perception vision or visual acuity worse than 5/200 to be very useful in ambulation. Avoidance of phthisis and maintenance of clear media promote healthier circadian rhythms. This may allow for more restful sleep and avoidance of depression which may substantially improve their quality of life. These are very important opinions that those of us who treat infants and children with potentially blinding disorders should take into consideration.

Tonometry in adults and children. Eisenberg, et al. Ophthalmology, volume 105, pages 1173-1181, 1998. Briefly the authors compared pneumotonometry, applanation tonometry and tono-pen tonometry in vitro and in vivo. Their conclusion was that the pneumotonometer performed best in children.

Pediatric intraocular lens implantation. Zwann, et al. Ophthalmology, volume 105, pages 102-119, 1998. The authors report a retrospective study of all children who underwent intraocular lens placement between 1989-1996. Follow up on all the children was a minimum of six months. Over three hundred children had had surgery. The majority of the patients had had cataracts due to trauma; 37% of the patients had infantile cataracts. Technically most of the patients did well. The most common peri-operative complication was fibrinous membranes in about 13% of the patients. The most common late complication was posterior capsule opacification. Despite the excellent technical results visual acuity of 20/40 or better were obtained in only 44% of the eyes and 20/80 or better in 70% of the eyes. The authors attribute the less than excellent visual results to poor compliance, young age and late referrals of many of the patients.

Surgical technique, visual outcome and complications of pediatric intraocular lens implantation. Simons, et al. Journal of Pediatric Ophthalmology and Strabismus, volume 36, pages 118-124, 1999. This is another retrospective study that evaluates the results of pediatric cataract extraction and IOL in children between the ages of two and twelve. This article nicely describes the authors' surgical technique, but does not discuss their complications. The anatomical and visual results are very similar to the study listed in article #9 above.

Refractive changes after pediatric intraocular lens implantation. Enyedi, et al. American Journal of Ophthalmology, volume 126, pages 772-781, 1998. This is part of an ongoing prospective study in which the refractive errors of all patients younger than eighteen who underwent cataract surgery with IOLs are periodically determined. Most of the patients had either traumatic or developmental cataracts. The article nicely describes the author's surgical technique, their decision making regarding IOL power and their peri-operative and post-operative care including the oral and topical medications that they used on their patients. They divided their patients into four groups depending on their age at surgery. Their data demonstrated that there was a trend towards post-operative myopia in all the patients. This trend and myopic shift was greatest in the younger age groups but was even present in the patients between six and eight years of age. It was only when patients were beyond eight years of age. It was only when patients were beyond eight years of age that there was not a significant myopic shift. The authors decided that their results support the practice of under correcting young children (i.e. targeting for hyperopia) at the time of cataract surgery.

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CASE REPORT - LIMBAL CORNEAL DERMOID

is currently five and a half years old. She was born in September, 1994 and shortly after birth she was noted to have a limbal corneal dermoid in her left eye. In May, 1998 when she was three and half years of age she had a visual acuity (using pictures) of 20/40 in each eye. The refraction in the right eye was + 1.25 -0.50 x 90. The left eye was +4.25 -3.25 x 120. Glasses were dispensed and she was referred to us for corneal topography. Topography at that time showed 5 diopters of cylinder in her left eye with readings of 40.50/45.18 x 25. The patient was followed by her pediatric ophthalmologist and she returned here in August, 1999 when she was nearly five years of age. Her vision with pictures now measured 20/30 in each eye. She was wearing the same spectacle correction as her previous exam. Topography of the left eye at this time gave readings of 37.33/44.76 x 27 approximately 7.5 diopters of cylinder. Topography was repeated two months later and gave readings of 37.8/45.7 x 34 with 8 diopters of corneal cylinder.

The questions regarding this case are as follows:

1. How would you currently manage this patient?
2. Would you have done anything different in the past?
3. Do you have experience with progressive astigmatism in young children with limbal dermoids?

This patient was presented at the last PKA Breakfast at the academy and again at the PKA Luncheon at ARVO. We are trying to collect a series of such patients to answer these management questions. Dr. Adam Kaufman was kindly provided a worksheet to assist in this endeavor.

Please respond by fax to (914) 493 - 7445 or by email to pedkera@aol.com.

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