Deep anterior lamellar keratoplasty in case of Hurler-Scheie syndrome

Keratoplasty: are children missing out on the lamellar revolution-the 2023 Bowman Club, David L. Easty Lecture

There has been a growing interest in lamellar keratoplasty over penetrating keratoplasty in the treatment of cornea diseases. Children, in particular, may benefit from lamellar keratoplasty due to faster visual recovery, better outcomes, fewer eye drops and earlier amblyopia treatment. This review aims to examine the trends, surgical techniques and outcomes in paediatric lamellar keratoplasty. Additionally, alternative treatment modalities to keratoplasty such as selective endothelium removal in Peters anomaly and ophthalmic non-steroidal anti-inflammatory drugs eyedrops in congenital hereditary endothelial dystrophy are also discussed.

Objectively measuring anterior segment alterations in the eyes of mucopolysaccharidoses: Its utility in early diagnosis of glaucoma

Purpose

Our study aimed to evaluate the utility of the anterior segment morphometry for objectively assessing anterior segment architectural changes of corneal clouding in the mucopolysaccharidoses (MPS) cohort and to investigate whether these measurements correlate with the slit-lamp findings on the cornea and early diagnosis of glaucoma.

Methods

This retrospective study involved 70 eyes of 35 children with cloudy cornea due to MPS variants. Anterior segment architectural alterations were measured using anterior segment imaging and biometry in MPS children and compared with controls.

Results

Mean age of the cohort at the time of assessment was 7.9 ± 4.5 years. Males constituted two-thirds of the cohort. Variants of MPS with cloudy cornea were as follows: Type I (62%), Type IV (11%), and Type VI (22%). Morphometric measurements were available in 22 eyes of 11 MPS children and an age-matched healthy control group. There were significant differences between MPS cohort and controls in refraction in Diopters (5.03 ± 0.39 and 0.01 ± 0.04; P < 0.0001), axial length (AXL) in mm (21.39 ± 0.28 and 23.04 ± 0.28; P = 0.0002), average keratometry in Diopters (40.67 ± 0.44 and 42.83 ± 0.44; P < 0.0001), anterior chamber depth (ACD) in mm (2.92 ± 0.07 and 3.65 ± 0.07; P < 0.0001), and intraocular pressure (IOP) in mmHg (25.2 ± 2.0 and 14.1 ± 2.3; P = 0.0003). Secondary glaucoma was observed in 28% of the MPS cohort.

Conclusion

The anterior segment morphometry in the cloudy cornea due to MPS provides an objective measurement of anterior segment architectural changes, thus diagnosing early-onset secondary glaucoma. These findings highlight that cloudy cornea due to MPS variants merits close monitoring throughout life.

Update on Pediatric Corneal Diseases and Keratoplasty

Managing pediatric corneal disorders is challenging as the prognosis of pediatric keratoplasty depends on several factors. Advancements in the genetic basis of congenital corneal diseases and investigations in congenital corneal conditions provide a better understanding of pediatric corneal conditions. Surgeons performing keratoplasty in children now have a choice of various techniques. Evolving surgical techniques of anterior lamellar and endothelial keratoplasties has expanded the management interventions in these pediatric corneal morbidity conditions; however, considerable concerns still exist in association with corneal transplantation in infants and children. Outcomes in pediatric keratoplasty depend upon the preoperative indications, the timing of surgical intervention, intraoperative and postoperative factors including the patient/care givers' compliance. Factors such as low scleral rigidity, higher rate of graft failure, need for frequent examinations under anesthesia, and difficulty in optimal visual acuity assessment still remain a considerable challenge in pediatric scenarios. In children, deprivation amblyopia as a result of the corneal opacification can adversely affect visual development, causing dense amblyopia. Outcomes to surgical interventions for management of corneal opacification in children is further compromised by the pre-existing amblyopia apart from the concerns of refractive outcome of the graft. Graft rejection, graft infection, amblyopia, and glaucoma continue to be serious concerns. In recent years both anterior and posterior lamellar keratoplasty techniques are being increasingly performed in pediatric eyes, which offer advantages in the form of lower risk of graft rejection. The timing of surgery, careful case selection, cautious intraoperative approach, and optimal postoperative management can improve the anatomical and functional outcome in difficult cases.

Long-Term Outcomes of Big Bubble Deep Anterior Lamellar Keratoplasty in Mucopolysaccharidoses: A Retrospective Case Series and Review of the Literature

PURPOSE

The purpose of this study was to report the long-term surgical and visual outcomes of patients with mucopolysaccharidoses (MPS) after big bubble deep anterior lamellar keratoplasty (BB-DALK).

METHODS

This was a retrospective case series of patients with MPS who underwent BB-DALK at a single academic institution. All patients had corneal clouding secondary to MPS limiting visual acuity for which keratoplasty was indicated. Each patient was evaluated and underwent surgery by a single surgeon. Reported data included age at keratoplasty, sex, MPS type, best spectacle-corrected visual acuity, change in pachymetry, ocular comorbidities, surgical complications, and MPS-related medication use.

RESULTS

Outcomes of 12 eyes from 7 patients with MPS type I (Hurler, Scheie, and Hurler-Scheie) are reported using the newest nomenclature. The mean follow-up was 5.58 years (range: 1-10 years). All cases underwent BB-DALK with a type 1 big bubble during the surgery. Two cases (16.6%) required rebubbling because of partial Descemet membrane detachment. One case was complicated by a suture abscess and required a penetrating keratoplasty. No episodes of rejection occurred. Statistically significant improvement in the best spectacle-corrected visual acuity (from a mean 0.85-0.33 logarithm of the minimum angle of resolution, P = logarithm of the minimum angle of resolution 0.0054) and pachymetry (mean reduction of -145.4 μm, P = 0.0018) was observed.

CONCLUSIONS

BB-DALK seems to be an acceptable long-term surgical option in patients with MPS. Our findings suggest that this technique is reproducible and can achieve clear corneal grafts with good visual results on a long-term follow-up.

Mucopolysacharidosis Type I Presenting as Bipolar Affective Disorder: A Case Report

Mucopolysacharidosis type I is a multisystem disease and often presents with neurobehavioral problems, corneal clouding, cardiac valve involvement, hepatomegaly, coarse facies, and skeletal abnormalities. It has three subtypes - with Hurler subtype (MPS-1H) being the most severe phenotype with early neurological involvement, rapid progression and mortality, while the other two subtypes - Hurler-Scheie (MPS-1H/S) and Scheie (MPS-1S) are of intermediate and milder severity, respectively. Even though neuropsychiatric symptoms have often been reported in the pediatric age group, MPS type I presenting as a major psychiatric illness in adulthood has rarely been reported in literature. Here, we report a female presenting as bipolar affective disorder in the fourth decade of life, where neuroimaging and systemic involvement gave a clue to the diagnosis.

Multimodal imaging of Hurler syndrome-related keratopathy treated with deep anterior lamellar keratoplasty

Background

Hurler syndrome-associated keratopathy is an exceedingly rare corneal disorder that requires corneal transplantation in advanced stages. Precise assessment of the corneal condition is necessary for deciding which type of keratoplasty (i.e., deep anterior lamellar or penetrating) should be proposed. We aimed to confront the results of multimodal imaging with those of histology in a case of Hurler syndrome-associated keratopathy.

Case presentation

A 16-year-old patient with Hurler’s syndrome treated with hematopoietic stem cell transplantation was referred for decreased vision related to advanced keratopathy. The patient was treated with deep anterior lamellar keratoplasty (DALK) in both eyes with uncomplicated outcome. Visual acuity improved from 0.1 (20/200) preoperatively to 0.32 (20/63) and 0.63 (20/32) after transplantation. The corneal endothelial cell density was 2400 cells/mm² in both eyes 3 years after transplantation. In vivo confocal microscopy (IVCM) and spectral domain optical coherence tomography (SD-OCT) were performed preoperatively. The corneal buttons retrieved during keratoplasty were processed for histology. In SD-OCT scans, corneal opacities appeared as diffuse stromal hyperreflectivity associated with increased corneal thickness. IVCM showed diffuse cytoplasmic granular hyperreflectivity and rounded/ellipsoid aspects of keratocytes, presence of small intracellular vacuoles, and hyperreflective epithelial intercellular spaces. Bowman’s layer was thin and irregular. The corneal endothelium was poorly visualized but no endothelial damage was observed. Histology showed irregular orientation and organization of stromal lamellae, with the presence of macrophages whose cytoplasm appeared clear and granular. A perinuclear clear halo was visible within the epithelial basal cells. Bowman’s layer featured breaks and irregularities.

Conclusions

The observed corneal multimodal imaging features in mucopolysaccharidosis-related keratopathy were concordant with histology. Compared with standard histology, multimodal imaging allowed additional keratocyte features to be observed. It revealed both morphological and structural changes of all corneal layers but the endothelium. This information is essential for therapeutic management which should include DALK as the first-choice treatment in case of impaired visual acuity.

Deep Anterior Lamellar Keratoplasty in a Case of Hurler-Scheie Syndrome Undergoing Enzyme Replacement Therapy

PURPOSE

To report successful management of corneal clouding associated with Hurler-Scheie syndrome with deep anterior lamellar keratoplasty (DALK) undergoing concurrent enzyme replacement therapy (ERT).

METHODS

A 13-year-old boy with Hurler-Scheie syndrome (MPS I-HS) presented with corneal clouding in both eyes. He was on ERT with laronidase (Aldurazyme; Genzyme, Cambridge, MA) and had a visual acuity of 20/32 in both eyes. Seven years later, visual acuity in his left eye decreased to counting fingers and DALK was performed for vision recovery. Two years later, visual acuity in his right eye decreased to 20/100 and DALK was performed.

RESULTS

At his last visit, which was 3 years after right eye DALK and 5 years after left eye DALK, the grafts were clear and the corrected visual acuity in his right and left eyes was 20/30 and 20/25, respectively.

CONCLUSIONS

The present case highlights the possible effectiveness of DALK in patients with mucopolysaccharidosis (MPS)-related corneal stromal opacification, treated with ERT.

Avoiding big bubble complications: outcomes of layer-by-layer deep anterior lamellar keratoplasty in children

BACKGROUND/AIMS

To describe the visual and clinical outcomes of manual layer-by-layer deep anterior lamellar keratoplasty (DALK) in a paediatric population.

METHODS

The charts of all children who underwent DALK surgery between January 2007 and January 2015 were reviewed retrospectively. Data collected included preoperative and postoperative spectacle-corrected distance visual acuity (CDVA), intraoperative and postoperative complications including graft rejection and failure. Residual posterior lamellar thickness (RPLT) and endothelial cell density (ECD) were measured in eyes with follow-up longer than 6 months.

RESULTS

Fifty-one eyes of 42 patients were included in the study. The mean patient age at surgery was 11.2±5.2 years and the mean follow-up time was 36.5±23.7 months. The most common indications for surgery were mucopolysaccharidosis (29.4%) and keratoconus (23.5%). Nine eyes (17.6%) had intraoperative microperforation, none of which were converted to penetrating keratoplasty (PKP). Only one eye (2.0%) was converted to PKP. Five eyes (9.8%) had a stromal rejection episode of which one eye failed. Another four eyes (7.8%) experienced graft failure among which three eyes (75%) had infectious keratitis. Three of the five failed grafts had a successful repeat DALK. The average RPLT was 81.9±36.5μm. ECD was significantly lower in the operated eye compared with the normal eye (3096±333 cells/mm² vs 3376±342 cells/mm², n=11, P=0.003). The mean postoperative CDVA was 0.5±0.4 logarithm of the minimum angle of resolution (logMAR) reflecting a gain of 0.3 logMAR (P<0.001).

CONCLUSION

Manual dissection DALK is a safe procedure in children with stromal opacities. Despite successful structural rehabilitation, functional recovery is still suboptimal mostly due to amblyopia.

Outcomes of keratoplasty in the mucopolysaccharidoses: an international perspective

OBJECTIVE

To describe visual outcomes after penetrating keratoplasty and deep anterior lamellar keratoplasty in patients with mucopolysaccharidoses.

METHODS

This is a retrospective review of keratoplasty in consecutive patients from Brazil, England, Finland, Germany, Portugal, Sweden and the USA. All patients had corneal clouding due to mucopolysaccharidoses. Preoperative and postoperative visual outcome and ocular comorbidities were identified. Success was arbitrarily defined as any improvement in visual acuity or best-corrected visual acuity better than logarithm of the minimum angle of resolution 0.30 (20/40). Statistical analysis included only data from first operated eyes in the 16 patients who underwent bilateral keratoplasty.

RESULTS

Forty-eight eyes from 32 patients with mucopolysaccharidoses I, IV or VI are reported. Mean follow-up was 70 months (range: 5-186). Penetrating keratoplasty was performed in 45 eyes and deep anterior lamellar keratoplasty in 3 eyes. At last follow-up, a successful visual outcome for penetrating keratoplasty in first operated/only operated eyes was found in 63%. Rejection episodes occurred in 23% of grafts; however, a clear graft was recorded at last follow-up in 94%. Ocular pathway comorbidities were identified in 63% of eyes transplanted.

CONCLUSIONS

Clear corneal grafts can be obtained for patients with corneal clouding due to mucopolysaccharidosis with improvement in visual acuity in the majority.