Posterior Polymorphous Dystrophy Research Articles

Integrated Intraoperative Optical Coherence Tomography for Pediatric Lamellar Corneal Transplant Surgery.

Integrated intraoperative anterior segment optical coherence tomography is an extremely valuable tool that can be used by corneal surgeons when performing pediatric lamellar corneal transplant surgery. This chapter will demonstrate its use in infants and children with a variety of corneal diseases. These diseases include congenital corneal opacities such as Peters' anomaly (both types I and II), surgical management of limbal dermoids, and its use in selective corneal transplant surgery such as DALK (deep anterior lamellar keratoplasty) or DSEK (Descemet stripping endothelial keratoplasty). These techniques could be used in children with anterior corneal scarring or storage disorders, such as mucopolysaccharidoses, or posterior endothelial disease, such as congenital hereditary endothelial dystrophy or posterior polymorphous dystrophy. This chapter will demonstrate the author's experience using this device during anterior segment corneal surgery.

Laser refractive surgery in corneal dystrophies.

Twenty-eight case reports and case series published between 2000 and 2019 concerning laser refractive surgery in patients with corneal dystrophies, resulting in 173 eyes from 94 patients, were included in this systematic review. Best results were achieved in posterior corneal polymorphous and Cogan dystrophy. Unfavorable results were found in Avellino dystrophy and Fuchs endothelial corneal dystrophy (FECD). Photorefractive keratectomy was not indicated in Meesmann and Avellino dystrophy. Laser in situ keratomileusis was indicated in posterior polymorphous corneal dystrophy but not in FECD, Avellino, or Cogan dystrophy. Small-incision lenticule extraction and other dystrophies such as lattice, fleck, Lisch, or François did not achieve enough scientific evidence to report any recommendation.

IC3D second edition: an update

AbstractThe International Committee for Classification of Corneal Dystrophies (IC3D) was created by the Cornea Society in Chicago in 2005 to revise the corneal dystrophy nomenclature. The initial group consisted of 15 corneal specialists and 2 ophthalmic pathologists from North America, Europe and Asia, chaired by Dr. Jayne Weiss. The first IC3D edition was published in 2008. Already 6 years later, sufficient new data had become available to begin revision of the IC3D by 13 original and 2 new corneal specialists and 1 original ophthalmic pathologist. The second edition was published in 2015. Like the first one it presents each dystrophy as a template with key characteristics and typical clinical images, but is now supplemented with typical anterior segment OCT and histopathologic images as well. The category of ‘Bowman layer dystrophies’ was replaced by ‘Epithelial–stromal TGFBI dystrophies’ and ‘Descemet Membrane and Endothelial Dystrophies’ was simplified to ‘Endothelial Dystrophies’ because Bowman and Descemet are acellular and secondarily affected. Congenital Hereditary Endothelial Dystrophy 1 (CHED1) was merged with posterior polymorphous dystrophy 1 (PPMD1). Posterior amorphous corneal dystrophy (PACD) was found to be caused by a joint deletion of keratocan (KERA), lumican (LUM), decorin (DCN), and epiphycan (EPYC) genes. After publication of the second IC3D, epithelial recurrent erosion dystrophy (ERED) has been linked with COL17A1 mutations across the world, and the so called ‘variant Thiel‐Behnke dystrophy’, that was dubious, was found to be identical with ERED. The corneal dystrophy field continues to develop, making a third edition likely in the future.

Posterior Polymorphous Dystrophy: An Unusual Presentation

Posterior Polymorphous Dystrophy (PPD) is a rare, innocuous and asymptomatic condition in which corneal endothelial cells display characteristics similar to epithelium. It is often bilateral and frequently asymmetric. We report a case of a 10-year-old girl with a family history of glaucoma who presented with right eye blurring of vision since few years. She had frequent spectacle-prescription changing due to unimproved visual acuity. Cycloplegic refraction revealed high astigmatism and moderate amblyopia over the right eye. Her best corrected vision was 6/9 for the right and left eyes. Slit-lamp examination showed a vesicular-like lesion at the periphery of corneal endothelial layers in both eyes. Endothelial cell density was much reduced on the right eye compared to the left, with more severe astigmatism. Other ocular examinations were unremarkable. Patient was instructed to patch her better left eye periodically. Although patients with Posterior Polymorphous Dystrophy (PPD) present at the age of adulthood, the age at diagnosis is highly variable. It is rare and inherited through an autosomal dominant pattern. PPD may rarely lead to astigmatism, by which was present in the patient due to the features of non-keratoconic and keratoconic cornea on the right and left eye, respectively. Endothelial cell counts were reduced more on the right eye compared to the left, which later may worsen her visual acuity thus indicating corneal transplant in the future. Patient also had a strong family history of glaucoma. Hence, screening of associated disease of corneal endothelial dystrophy in the family may be necessary.

LASIK in selected patients with posterior polymorphous corneal dystrophy

Purpose The aim of the present study was to evaluate the safety of LASIK surgery in patients with posterior polymorphous corneal dystrophy. Patients and methods A total of 25 eyes of 13 patients with posterior polymorphous dystrophy with various refractive errors were selected for LASIK treatment and were followed up for 2 years after surgery. Results All eyes included in the study showed an improvement in unaided visual acuity with no postoperative complications. Conclusion LASIK can be a safe procedure in patients with posterior polymorphous dystrophy and proper selection criteria.

Posterior polymorphous dystrophy, case report and literature review

Case reportPosterior polymorphous dystrophy (DPP) is a rare posterior corneal dystrophy that is genetically transmitted as autosomal dominant. Corneal structures affected in this dystrophy are Descemet membrane and the endothelium. A case is presented on a 47-year-old woman with no relevant history, with typical findings of DPP (vesicular and band lesions at the endothelium and posterior Descemet). DiscussionTo our knowledge there are no reported cases of DPP in Latin-American patients in the literature. The clinical manifestations in our patient were found to be very similar to the cases reported in other populations.

Preloaded donor corneal lenticules in a new validated 3D printed smart storage glide for Descemet stripping automated endothelial keratoplasty

PurposeTo design and validate the efficacy of three-dimensional (3D) printed smart storage glide (SSG) which is capable of preserving and delivering posterior lenticules for Descemet stripping automated endothelial keratoplasty (DSAEK).MethodsLaboratory...

Corneal dystrophies and genetics in the International Committee for Classification of Corneal Dystrophies era: a review

Many of the corneal dystrophies have now been genetically characterized, and a system was established in 2008 by The International Committee for Classification of Corneal Dystrophies (IC3D) in an attempt to standardize the nomenclature. IC3D provided a classification system whereby all dystrophies can be categorized on the basis of the underlying genetic knowledge. Since that time, further work has established even more phenotypic and allelic heterogeneity than anticipated, particular for Fuchs endothelial corneal dystrophy and posterior polymorphous dystrophy. Using genome-wide association studies, a number of genes are now implicated both in normal corneal quantitative traits, such as central corneal thickness, as well as in disease. There is also a trend towards functional characterization of the genetic variants involved to elucidate the pathophysiology of these entities. This review article will provide an overview of the knowledge to date, with an emphasis on findings since the IC3D classification was published in 2008.

Clinicopathologic Findings in Iridocorneal Endothelial Syndrome and Posterior Polymorphous Membranous Dystrophy After Descemet Stripping Automated Endothelial Keratoplasty

To report the histopathologic findings of the iridocorneal endothelial (ICE) syndrome and posterior polymorphous membranous dystrophy (PPMD) in 3 patients who underwent Descemet stripping automated endothelial keratoplasty (DSAEK), and to correlate these findings with the clinical diagnosis. Three patients with clinical findings compatible with either ICE syndrome (1 patient) or PPMD (2 patients) underwent DSAEK. The DSAEK specimens were processed for light microscopy, immunhistochemical staining for cytokeratins AE1/3 and MAK6, and electron microscopy. Examination of the DSAEK specimens showed multilayered endothelial cells and thickened Descemet membrane in all cases. Immunohistochemical staining for cytokeratins was positive in the endothelium in all cases. Ultrastructural examination showed a thickened Descemet membrane and wide-spaced collagen in Descemet membrane in 1 case of PPMD but not in 2 cases of ICE syndrome, including 1 case that carried the clinical diagnosis of PPMD. In 2 cases, the histopathologic evaluation of the DSAEK specimen confirmed the clinical diagnosis; however, in 1 case the pathological diagnosis was ICE syndrome, while the clinical diagnosis was PPMD. ICE syndrome and PPMD can be diagnosed and differentiated from one another by histopathologic evaluation of corneal specimens obtained at the time of DSAEK. We recommend submitting the corneal tissue obtained during DSAEK for pathological examination when the etiology of corneal edema is unclear.

Analysis of the misdiagnosis of bilateral iridocorneal endothelial syndrome

To analyze the misdiagnosis of bilateral iridocorneal endothelial (ICE) syndrome and the possible reasons. The patients seen from January 1998 to December 2011 at Beijing Tongren Hospital, misdiagnosed as bilateral ICE syndrome, were analyzed retrospectively. And a literature search was performed with a Wanfang computerized database website for the case studies of bilateral ICE syndrome. The history, clinical profiles and the findings of corneal, iris and anterior chamber examinations were analyzed. The clinical manifestations of patients with ICE syndrome were also compared with those of Axenfeld-Rieger syndrome, posterior polymorphous dystrophy (PPMD) and chronic iritis for differential diagnosis. Ten patients were diagnosed as bilateral ICE syndrome. However, among them, 5 patients were diagnosed as Axenfeld-Rieger syndrome, 2 patients as PPMD, 3 as chronic iritis and none as bilateral ICE syndrome. There were 9 Chinese reports of bilateral ICE syndrome in a total of 18 patients. Analysis showed that Axenfeld-Rieger syndrome needed to be ruled out in 10 patients, PPMD could not be ruled out in 2 patients while diagnosis could not be made in 6 patients for a lack of proof. Despite the reporting of bilateral cases, ICE syndrome is usually unilateral. With specific micrographic features for a definite diagnosis of ICE syndrome, ICE cells may become an important feature differentiating from Axenfeld-Rieger syndrome, PPMD and chronic iritis.

Descemet stripping automated endothelial keratoplasty in pediatric age group

PurposeTo report the outcomes of DSAEK surgery performed in pediatric patients. DesignNoncomparative interventional case series. Subjects and methodsAll pediatric patients (age up to 16years) undergoing Descemet automated stripping endothelial keratoplasty (DSAEK) at our Institution since January 2008 have been enrolled in a prospective study. A standard DSAEK, involving delivery of an 8.5–9.5mm graft by Busin glide, was performed under general anesthesia in 19 eyes of 11 pediatric patients (congenital hereditary endothelial dystrophy n=13; congenital glaucoma n=2; posterior polymorphous dystrophy n=2, and failed penetrating keratoplasty n=2). Slit-lamp examination, refraction and visual acuity as well as endothelial cell density were evaluated preoperatively as well as 1, 3, 6, 12, and 18months postoperatively. ResultsAll surgical procedures were uneventful. Graft detachment occurred in 4 cases and was managed successfully with repeat air injection. All corneas cleared within a week from surgery. Follow-up was 3–18months. At last follow-up examination, best-corrected visual acuity (BCVA) was better than 20/40 in 8 of the 13 cases of patients old enough to assess vision. A graft rejection episode was seen in 1 case within 3months from surgery but was reverted with steroidal treatment. No graft failures were observed. ConclusionsDSAEK is an appropriate surgical intervention for children with corneal endothelial failure. In contrast to penetrating keratoplasty (PK), DSAEK is performed under “closed system” conditions, thus minimizing intraoperative risks. Finally, healing is much faster than with PK and all sutures can be removed within 2–4weeks from surgery, thus allowing fast visual recovery and prompt starting of amblyopia treatment.

Spontaneous Corneal Clearing after Descemet's Stripping without Endothelial Replacement

To report spontaneous corneal clearing with improved visual acuity and central endothelial cell repopulation after Descemet's stripping without endothelial replacement. Interventional case report. A 34-year-old woman with bilateral decreased vision secondary to corneal edema from endothelial dysfunction underwent Descemet's stripping endothelial keratoplasty (DSEK) in the right eye and Descemet's stripping only in the left eye. Histopathologic evaluation confirmed a dual diagnosis of Fuchs' endothelial dystrophy and posterior polymorphous membrane dystrophy from Descemet's membrane specimens removed from each eye. After primary graft failure with regraft in the right eye, the second posterior corneal lenticule detached and was removed and not replaced. The cornea cleared, and central endothelial cell repopulation was documented by confocal microscopy. Therefore, Descemet's stripping without endothelial replacement was performed in the left eye. The left cornea also cleared with central endothelial cell repopulation. Postoperative visual acuity and central endothelial cell repopulation. Endothelial migration after Descemet's stripping alone in the left eye, with probable host endothelial cell repopulation in the right eye. Endothelial cell migration after Descemet's stripping procedure without insertion of endothelial graft can occur, resulting from host endothelial cell repopulation with corneal clearing and improved visual acuity.

Photorefractive keratectomy in posterior polymorphous dystrophy with vesicular and band subtypes

To evaluate the safety and efficacy of photorefractive keratectomy (PRK) in patients with posterior polymorphous dystrophy (PPMD) with vesicular and band subtypes. Walter Reed Center for Refractive Surgery, Washington, DC, USA. Case series. The records of patients with PPMD who had PRK between January 2002 and May 2009 were reviewed. Data for analysis included sex, age, ablation depth, residual stromal bed thickness, manifest spherical equivalent, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, central corneal thickness (CCT), endothelial cell density (ECD), intraocular pressure (IOP), and complications. Preoperative and postoperative results were compared using the Wilcoxon signed-rank test, with P < .05 considered significant. Fourteen eyes of 7 men (mean age 29.1 years ± 9.1 [SD]; range 21 to 42 years) with at least a 6-month follow-up were reviewed. At the final follow-up (mean 19.5 months; range 6.3 to 58.3 months), all eyes had a UDVA of 20/15 and all eyes were within ± 0.50 diopter of emmetropia. The CDVA was unchanged from preoperatively in 71.4% of eyes and improved by 1 line in 28.6%. There were no significant complications. The IOP did not change significantly over the follow-up (P = .272). At the final visit, the mean ECD (2795.3 ± 366.0 cells/mm(2)) was unchanged from baseline (2809.1 ± 338.3 cells/mm(2)) (P = .114). Photorefractive keratectomy in PPMD patients with vesicular and band subtypes resulted in excellent visual outcomes and a low incidence of adverse effects. Endothelial cell densities did not change significantly in the early postoperative period. No author has a financial or proprietary interest in any material or method mentioned.

Descemet-stripping Automated Endothelial Keratoplasty—A Review

Descemet-stripping automated endothelial keratoplasty (DSAEK) has become the procedure of choice to treat corneal endothelial dysfunction. The technique involves replacing the diseased host endothelium with a graft consisting of a thin layer of posterior stroma, Descemet membrane, and endothelium. In comparison to penetrating keratoplasty (PK), DSAEK confers quicker visual and structural recovery with absence of corneal surface incisions or sutures, and limits astigmatism. DSAEK has been proved to successfully achieve favorable visual acuity and graft clarity in bullous keratopathy, posterior polymorphous dystrophy, and failed PK grafts. This article discusses various DSAEK surgical techniques, short- and longterm post-surgical results, complications, and comparisons with other types of keratoplasty. With the advent of Descemet membrane endothelial keratoplasty (DMEK), in which only Descemet membrane is transplanted, visual rehabilitation may be attained sooner.

Posterior Polymorphous Dystrophy and Keratoglobus in a Child

A 13-year-old boy presented with gradually progressive deterioration of vision in both eyes, bilateral photophobia, and regular headaches. Clinical examination, anterior segment findings, and specular microscopy findings were consistent with the diagnosis of posterior polymorphous dystrophy and keratoglobus. To the authors' knowledge, this is the first pediatric case and the second case overall of the simultaneous occurrence of posterior polymorphous dystrophy and keratoglobus.

Observation of posterior corneal vesicles with in vivo confocal microscopy and anterior segment OCT

The histopathology of posterior corneal vesicles (PCV) has not yet been revealed. A 15-year-old girl, who was diagnosed by slit-lamp microscopy as PCV, was examined using specular microscopy, in vivo confocal microscopy, and anterior segment OCT (optical coherence tomography). Anterior segment OCT showed that the thickness of both corneas was within normal limits. At the same time, in vivo confocal microscopy revealed endothelial cells in the rounded dark areas, acellular hyporeflective layers on the Descemet’s membrane, and hyperreflective linear lesions. These findings were not reported previously by slit-lamp and specular microscopy. The abnormal findings only existed at the Descemet’s membrane and corneal endothelial layer. Previous reports dealing with posterior polymorphous dystrophy (PPMD) examined using in vivo confocal microscopy reported almost the same findings, suggesting that PCV and PPMD may be the same at the microstructural level.

Dystrophia Helsinglandica: a new type of hereditary corneal recurrent erosions with late subepithelial fibrosis

To describe the phenotype of an autosomal-dominant corneal dystrophy with an early onset of recurrent corneal erosions and development of subepithelial fibrosis in the cornea, and also to exclude genetic linkage to known corneal dystrophies with autosomal-dominant inheritance and clinical resemblance. We describe the medical history and clinical findings in individuals from a seven-generation family with recurrent corneal erosions. A total of 43 individuals were evaluated by ophthalmological examination. Genomic DNA was prepared from peripheral blood and polymorphic microsatellite markers were analysed to study haplotypes surrounding genes causing corneal dystrophies with similar phenotypes. Erosive symptoms usually lasted for between 1 and 10 days. By the age of 7 almost all of the affected individuals suffered from recurrent corneal erosions. The attacks generally declined in frequency and intensity from the late 20s, but all examined individuals had developed subepithelial fibrosis by the age of 37. The fibrosis generally started in the mid periphery and was followed in some family members by central fibrosis and the development of gelatinous superficial elevations. Only a marginal reduction of visual acuity was seen in a few individuals. The affected individuals did not share haplotypes for genetic microsatellite markers surrounding genes that are known to cause autosomal-dominant corneal dystrophies. We describe a new type of autosomal-dominant corneal disorder with recurrent corneal erosions and subepithelial fibrosis not significantly affecting visual acuity.

The clinical spectrum between posterior polymorphous dystrophy and iridocorneal endothelial syndromes

Background There are many conditions affecting the corneal endothelium with similar clinical appearances, though with different prognoses, management approaches, and pathophysiologic development. Case A 39-year-old black woman with a previous diagnosis of asymmetric corneal posterior polymorphous dystrophy (PPMD) presented complaining of irritation in the left eye, worsening over the last week. On examination, her left eye had profuse edema and bullous keratopathy overlying a large placoid gray lesion at the level of the endothelium. Gonioscopy of the left eye found evidence of a membranous development extending from the endothelium to the trabecular meshwork. Examination of her right eye found a perfectly clear cornea and a normal angle. The patient subsequently had Chandler's syndrome diagnosed in the left eye, an iridocorneal endothelial (ICE) syndrome, rather than PPMD. Discussion PPMD and ICE syndromes present with many similarities; these clinical entities are in fact thought to be variants of the same disease. Unlike PPMD, Chandler's syndrome is unilateral, acquired, and typically symptomatic and progressive. It also characteristically affects middle-age women. Conclusion Understanding the clinical features of PPMD and ICE syndromes is important in proper diagnosis and management.

Ocular manifestations and surgical results in patients with Alport syndrome

We report the ocular manifestations of Alport syndrome and the surgical results in 4 patients. All 4 patients had anterior lenticonus; 2 also had posterior lenticonus in both eyes, 3 had flecked retina, and 1 had posterior polymorphous dystrophy. In both eyes of the 4 patients, phacoemulsification with intraocular lens (IOL) implantation was performed to treat anterior and posterior lenticonus. The postoperative visual acuity was excellent in all patients. We recommend phacoemulsification with IOL implantation as a safe and effective procedure in patients with lenticonus secondary to Alport syndrome.

Novel Corneal Phenotype in a Patient With Alport Syndrome

To report the clinical and histopathologic findings of an unusual keratopathy, which may represent a new corneal dystrophy in a patient with Alport syndrome (ATS). A 59-year-old woman with longstanding diagnosis of autosomal recessive ATS was evaluated for progressively decreasing vision in the left eye. She had anterior lenticonus and cataract and central corneal stromal opacification with significant thinning and flattening bilaterally. She underwent penetrating keratoplasty and cataract extraction with posterior chamber intraocular lens implantation. We describe the light microscopic and ultrastructural findings from the cornea. Histopathology of the corneal button revealed marked stromal thinning with decreased keratocytes. The endothelial cells were attenuated and focally lost. Immunohistochemical stains for cytokeratin were positive, findings consistent with posterior polymorphous dystrophy (PPMD). Transmission electron microscopy showed necrosis and a marked loss of keratocytes. Multilayering of the endothelium was consistent with PPMD, but mature desmosomes and microvilli were absent. In vivo confocal microscopy on the fellow eye showed linear hyporeflective bands at the level of Descemet's membrane consistent with PPMD. In addition, there were fine linear changes in the deep stroma and diffuse hyperreflectivity of the mid and superficial stroma with lack of identifiable keratocytes throughout. We believe this to be the first reported case to demonstrate some histopathologic features of PPMD in ATS. However, the clinical, histopathologic, and ultrastructural characteristics are not typical of PPMD. This may represent a new phenotypic expression of PPMD or may be a distinct clinicopathologic dystrophy associated with ATS.