March 2009

 

OPHTHALMOLOGY NEWS

 

Special patients, special considerations


by Matt Young EyeWorld Contributing Editor

 

 
Penetrating keratoplasty has been found safe in mildly and moderately mentally retarded patients, and even in some severely or profoundly mentally retarded patients Source: Edward J. Holland, M.D.

It’s hard enough getting superior outcomes after corneal transplantation. Performing transplants on mentally retarded patients makes things even more difficult, but a new study suggests proper patient selection even among this group for penetrating keratoplasty (PK) may help achieve excellent outcomes. “We consider PK a safe procedure in mildly and moderately mentally retarded patients and in severely or profoundly mentally retarded patients without associated eye rubbing or self-trauma behavior,” reported lead study author Gerardo P. Garcia Garcia, M.D., Department of Ophthalmology, University General Hospital of Alicante, Alicante, Spain. “Clear graft rates in this group are similar to those reported in the general keratoconus population.”

The researchers interestingly differentiated mental retardation from associated behaviors in drawing conclusions because, as it turns out, compulsive eye rubbing is bad for outcomes, but not all severely mentally retarded patients are compulsive eye rubbers, although many are. Some of their patients had very long term follow-up, as the mentally retarded patients analyzed underwent PK as early as 1978. This also limited the scope of the study, however, as lamellar keratoplasties were not performed then. The authors nonetheless suggested that newer techniques may help mentally retarded patients even more in some cases.

Down syndrome not visually down and out

Dr. Garcia Garcia and colleagues analyzed 39 PKs for keratoconus performed on 28 eyes of 20 mentally retarded patients between 1978 and 2007. Patients had Down syndrome, save for a couple with autism, and one diagnosed with perinatal hypoxia.

Eleven corneas had hydrops (39.29%), eight had corneal scarring (28.57%), four had hydrops and corneal scarring (14.29%), and two had descemetocele (7.14%). Uncomplicated keratoconus occurred in three patients (10.71%). Visual acuity, meanwhile, was recorded in only four patients (seven eyes) pre-op due to non-cooperation or language impairment. It was found to be lower than 10/100 in four eyes, 20/100 in two eyes, and 10/100 in one eye. Overall, graft survival rate was 82.14%, which is generally acceptable even in the general population for patients who undergo PK for diseases other than keratoconus. “In mild and moderate level of mentally retarded patients, clear graft rates reach 95.23%, like in general keratoconus population,” Dr. Garcia Garcia reported. Certain factors, though, made complications worse.

Eye rubbing

The researchers found that eye rubbing was a common trait among this mentally retarded group; 40% did so. “Both the frequency and severity of complications were higher in this group,” Dr. Garcia Garcia noted. “All the cases of corneal ulcerations and ptisis bulbi and 65% of all immunological graft rejection episodes were also developed by these patients. In addition, 78% of the regrafts were undergone in patients with compulsive eye rubbing.”

Eye rubbing, however, did not cause wound separation in any case.

Severe mental retardation

“Severe and profound levels of mental retardation were also related to a greater incidence and severity of complications,” Dr. Garcia Garcia reported. “All eyes that evolved to ptisis bulbi, 93% of the corneal ulcerations, and 40% of the primary immunological graft rejections were developed by patients of this group. These results may confirm the association between severe and profound levels of mental retardation and worse survival of the graft that other authors defend.”

However, mental retardation itself may not be what causes frequent PK complications. Rather, the compulsive eye rubbing, which occurred in 75% of the severe and profoundly mentally retarded group, could be the problem. Ocular self-trauma, which occurred in 50% of such patients, also clearly is problematic. Interestingly, the only profoundly mentally retarded patient without compulsive eye rubbing and ocular self-trauma did not have relevant post-op complications. The patient’s graft also remained clear. So again, behavior patterns—rather than severe or profound mental retardation—may be more relevant to the likelihood of complications, according to the researchers.

Mild to moderate mental retardation

“Mildly and moderately mentally retarded patients who underwent PK obtained excellent results, similar to the general keratoconus population, with a low rate of complications in the follow-up and clear grafts,” Dr. Garcia Garcia reported. “All the eyes with PK in mildly and moderately mentally retarded patients still had clear grafts at the final examination.”

Better caregivers could help Although all caregivers for these mentally retarded patients were trained to detect ocular problems post-op and apply eye drops correctly, not all caregivers were alike. “We cannot verify this hypothesis, but we could observe that patients with postoperative care by home caregivers with superior degree of academic training shown a lower rate of complications and a better visual prognosis than the patients who took care by caretakers with medium or low degrees of academic training, independently of the level of mental retardation or compulsive eye rubbing,” Dr. Garcia Garcia reported. “In eight patients whose caregivers had superior levels of academic training, there were no complications, all grafts remained clear and were related to only two episodes of immunologic graft rejection precociously detected and resolved with medical treatment.”

Deep lamellar keratoplasty an option

Deep lamellar keratoplasty, mainly indicated for transplant cases in which endothelium is not damaged, could be a good option for even the profoundly mentally retarded with behavioral problems. “This is an attractive new technique in the special group of the mentally retarded patients because the structural integrity of the globe is better maintained, and the corneal endothelium remains intact, lowering the risk of immunological graft rejection and also visual rehabilitation is faster than with PK,” Dr. Garcia Garcia reported. “Now we consider LK to be a safe alternative procedure in patients who exhibit marked compulsive patterns of behavior and in severe or profound levels of mental retardation, bearing in mind that this procedure is technically more difficult to perform and has traditionally shown inferior optical results when compared with PK.”

Meanwhile, John D. Sheppard, M.D., professor of ophthalmology, microbiology, and immunology, Eastern Virginia Medical School, Norfolk, Va., has a wealth of experience performing penetrating keratoplasty on Down syndrome patients. From his perspective, these patients need more attention pre-op, but can do very well post-op. “They are a lot more time intensive and overhead intensive in terms of preparation and anesthesia,” Dr. Sheppard said. “Sometimes it’s good to treat them like pediatric patients. But they are mostly very docile and compliant.” They have comparable outcomes to the normal population, Dr. Sheppard said, although sometimes you can’t get full cooperation in measuring visual acuity. But for Down syndrome patients, PK can “literally be life changing,” Dr. Sheppard said.

Editors’ note: Dr. Garcia Garcia has no financial interests related to this study. Dr. Sheppard has no financial interests related to his comments.

Contact information

Garcia Garcia: zemfira36@hotmail.com
Sheppard: 757-622-2200, docshep@hotmail.com

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