Corneal Degeneration Research Articles

Avoidable blindness and its correction in schools for the blind in Gujarat, India

Background: The primary objectives of our study were to determine the causes of blindness in blind school students, to ascertain the need for spectacles and magnifiers as low vision devices (LVD) in these children with useful residual vision and to determine the acceptance of magnifiers in different ocular pathologies Methods: The various causes of blindness were analysed in 179 blind female students in terms of the anatomical disorder present, the age of the child at the time of presentation with the visual disorder and the visual outcome observed after prescription of spectacles, magnifiers and non-optical devices. Results: Microphthalmos (44%), corneal scars (13.4%), anophthalmos (11.7%), optic atrophy (10.6%) and retinal dystrophies (10.1%) accounted for the major causes of blindness. 63.1% of blind children had an undetermined age of onset of visual impairment. Majority of the cases with anophthalmos, retinitis pigmentosa, corneal degeneration, microphthalmos, buphthalmos, staphylomas and retinal dystrophies benefitted with the use of non-optical devices. 60% of the aphakic and pseudophakic eyes were prescribed magnifiers. Conclusions: Spectacles and low vision devices do have a promising role in the visual rehabilitation of the ‘incurably blind children’.

BILATERAL RING-SHAPED CORNEAL OPACITY: CASE REPORT AND REVIEW OF THE LITERATURE

Purpose: To describe a bilateral corneal ring-shaped opacity that does not resemble any known corneal degeneration, dystrophy or other disorder, that occurs without any associated ocular or systemic disease. Methods: Case report and review of literature. Results: The authors describe the clinical history and examination of an 80 year old man, with an asymptomatic ring-shaped corneal opacity, bilateral and symmetrical, in the deep stroma of the corneal mid-periphery. The surrounding corneal stroma was clear, and the tear film, epithelium and its basement membrane, Descemet's membrane and endothelium were normal. This rare corneal anomaly was discovered by chance and its etiology is unknown. Conclusions: These rings may result from deposits of unknown origin or possibly a rare corneal dystrophy.

Climatic Droplet Keratopathy in Argentina: Involvement of Environmental Agents in Its Genesis Which Would Open the Prospect for New Therapeutic Interventions.

Climatic droplet keratopathy (CDK) is a degenerative corneal disease of unknown etiology. We described CDK for the first time in Latin America in the Argentinean Patagonia (El Cuy). A deeper knowledge of CDK pathogenic mechanisms will provide new therapeutic strategies. For that reason we investigated the prevalence of CDK in El Cuy and its existence in other 3 provinces with similar climate. Patients eyes were examined, habits throughout lives were inquired about, and serum ascorbate (sAA) was determined. All individuals work outdoors for most of the day. All regions had normal O3 levels. Individuals from regions 1, 2, and 3 had very low consumption of vegetables/fruits and low sAA levels. Conversely, region 4 individuals had balanced diet and higher sAA concentrations. CDK was only found in region 3 where individuals had partial deficiency of sAA and did not use eye protection. No CDK was found in regions 1 and 2 where individuals had similar work activities and dietary habits to those in region 3 but wear eye protection. No disease was found in region 4 where individuals work outdoors, have balanced diet, and use eye protection. To summarize, the CDK existence was related not only to climate but also to the dietary habits and lack of protection from sunlight.

Prevalence of corneal diseases in the rural Indian population: the Corneal Opacity Rural Epidemiological (CORE) study

ObjectiveThe present population-based study was undertaken to estimate the prevalence, determinants and causes of corneal morbidity and blindness in a rural North Indian population.DesignPopulation-based study in India with 12 899...

Peripheral hypertrophic subepithelial corneal degeneration presenting with bilateral nasal and temporal corneal changes.

To characterise the history, clinical and histopathological features of patients with bilateral nasal and temporal peripheral hypertrophic subepithelial corneal degeneration in a German population. A detailed ophthalmological and dermatological history and clinical findings were recorded of nine patients with bilateral simultaneous nasal and temporal peripheral corneal degeneration from two centers in Germany. Excised tissues were studied by histopathology, immunohistochemistry, and transmission electron microscopy. Foreign body sensation and need of artificial tear substitutes were the only symptoms reported regularly. Schirmer's and Jones-test were normal in all, but fluorescein break-up time of >10 s was found in five eyes of four patients. Best corrected visual acuity was reduced only under glare conditions. Corneal topography revealed irregular astigmatism in 13 of 14 eyes. Follow-up median time was 35 months. Most cases were stable within the follow-up period. Light and electron microscopy revealed the findings of superficial vascularised corneal hypertrophic scars, oxytatlan fibers, and discontinued Bowmans layer. In this series of German patients with peripheral hypertrophic subepithelial corneal degeneration, the changes were predominantly located in the palpebral aperture and often present in both eyes. No associated surface disease could be established in this study. Light and transmission electron microscopy showed histological features that are similar to Salzmann's corneal changes without any inflammation. We hypothesise that light exposure and a localised limbal insufficiency could be involved in the pathogenesis.

Anterior amorphous corneal opacity and corneal thinning

PurposeTo present the clinical features of four cases with bilateral anterior amorphous corneal opacity. MethodsA retrospective study in four patients with bilateral anterior amorphous corneal opacity was conducted. Examinations included visual acuity, keratometry, slit-lamp biomicroscopy, confocal microscopy, anterior segment optical coherence topography, and histology. ResultsThree female and one male patients (mean age, 52.3 ± 8.9 years) showed bilaterally oval, amorphous sheetlike corneal opacities with central depression and thinning. Superior limbal opacities were observed in two of these patients. The best-corrected visual acuity ranged from 20/50 to 20/400, and the mean of the keratometry was 39.81 ± 3.97 D (diopters). They had mild dry eyes. The anterior segment optical coherence topography demonstrated hyporeflective abnormalities in the anterior depressed stroma in these four patients. Confocal microscopy revealed large round cells at the epithelial layer in one patient, and amorphous opacities with some strand-shaped opacities in the anterior stroma in all four patients. The mean of the corneal endothelial cells density in the eight eyes was 1521 ± 402 cells/mm2. Central corneal stromalysis occurred in three patients, and descemetocele developed in two eyes. One patient received penetrating keratoplasty and two underwent lamellar keratoplasty. The histology of the corneal specimen revealed edematous basal epithelial cells, focal collagen disorganization in the thin stroma, and wartlike excrescences in a thickened Descemet's membrane. ConclusionAnterior amorphous corneal opacity is a rare keratopathy and may be one kind of rare corneal degeneration or dystrophy. Corneal stromalysis may occur in hyporefrective amorphous opacities and progress to descemetocele.

Simultaneous Conventional Photorefractive Keratectomy and Corneal Collagen Cross-linking for Pellucid Marginal Corneal Degeneration

To present the results after simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking for pellucid marginal corneal degeneration. In this prospective, interventional case series, 6 patients (8 eyes) with pellucid marginal corneal degeneration were enrolled. All patients underwent simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking; corneal epithelium was removed by transepithelial phototherapeutic keratectomy during treatment (Cretan protocol plus conventional photorefractive keratectomy). Visual and refractive outcomes were evaluated along with endothelial cell density preoperatively and at 1, 3, 6, and 12 months postoperatively. No intraoperative or postoperative complications were observed in any of the patients. LogMAR mean uncorrected distance visual acuity improved significantly from 1.05 ± 0.33 preoperatively to 0.41 ± 0.27 (P = .018) at 12 months postoperatively. Mean corrected distance visual acuity did not change significantly (P > .05) postoperatively. Mean spherical equivalent improved significantly from -3.52 ± 2.29 diopters preoperatively to -1.57 ± 1.76 diopters (P = .028) at last follow-up. Mean corneal astigmatism was significantly reduced from -6.83 ± 2.33 diopters preoperatively to -4.71 ± 1.89 diopters (P = .018) at the last follow-up. No endothelial cell density alterations were observed throughout the follow-up period (P > .05). Simultaneous conventional photorefractive keratectomy combined with corneal collagen cross-linking seems to be an effective, safe, and promising treatment for the management of pellucid marginal corneal degeneration.

Peripheral hypertrophic subepithelial corneal degeneration – clinical and histopathological features

To refine the diagnostic criteria for peripheral hypertrophic subepithelial corneal degeneration (PHSD) and characterize its clinical phenotype, histopathology and immunohistochemical features. Diagnostic criteria were refined on the basis of literature data. Fourteen patients (13 women and one man; median age 52 years, range 33-66) were identified based on these criteria. Keratectomy specimens were evaluated via routine and immunohistochemical stainings. The main outcome measures were symptoms, clinical phenotype, immunological status and histopathologic results. We defined the diagnostic criteria of typical PHSD as elevated circumferential and perilimbal subepithelial fibrosis with focal superficial corneal neovascularization, which were supported by female sex (93%), bilaterality (86%), the centre being in the upper quadrants (81%) and irregular astigmatism of two dioptres or more. The typical symptoms were reduced vision (86%) and the symptoms of ocular surface disease (64%). Light microscopy showed fibrosis with abundant collagen deposition but no inflammation in all patients. An immunohistochemical analysis of nine patients showed uniform staining for vimentin in three distinct types of fibroblasts in variable proportions: keratocyte-like cells that were positive for CD34, myofibroblasts that were positive for smooth muscle actin (SMA) and fibroblasts that were negative for CD34 and SMA. Small numbers of CD68-positive macrophages were also found. Peripheral hypertrophic subepithelial degeneration is characteristic of middle-aged women, in whom it is typically a bilateral idiopathic degeneration of the cornea associated with ocular surface disease and reduced vision. The fibrotic lesions probably undergo remodelling, inducing changes in corneal contour. A smouldering low-grade inflammation favouring low TGF-β1 concentrations is postulated as the primary pathological process leading to PHSD.

Intrastromal Corneal Ring Segment with and without Collagen Corneal Crosslinking vs Penetrating Keratoplasty for the Treatment of Keratoconus

ABSTRACT Keratoconus (KC) is a noninflammatory progressive corneal degeneration that cause irregular astigmatism especially in moderate and advanced cases, the irregular astigmatism can not be corrected by glasses, contact lenses are the only optical way for improving the visual acuity (VA) in these patients. In this retrospective study, we shall present the results of eight patients suffering from KC who were treated by PKP in one eye (PKP group) and ICRS (ICRS group) with or without CXL in the second eye. All the ICRS surgeries, the CXL and the PRK were performed at the I Vision, Refractive Surgery and Keratoconus Treatment Center in Haifa, Israel, by the same surgeon (AB), the PKPs were performed elsewhere, because they were treated in our medical center after the PKP. How to cite this article Barbara R, Barbara A. Intrastromal Corneal Ring Segment with and without Collagen Corneal Crosslinking vs Penetrating Keratoplasty for the Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2014;3(2):88-94.

Ozone therapy in ophthalmology

Currently, ozone therapy is a method of treatment used in various fields of medicine, e.g., in treatment of neuropathies, liver diseases, as well as in cosmetology, surgery, traumatology, obstetrics, gynecology, urology, cardiology, pulmonology, gastroenterology, neurology, dentistry, otorhinolaryngology, ophthalmology. Recently, ozone therapy is increasingly used clinically as a complement to the classical treatment, which is contributed by the low cost and relative safety of the method. Ozone therapy as a modern and effective method of treatment continues to evolve, finding new areas of application, mechanisms of its action are being clarified, new techniques and new indications are offered. The main properties of ozone therapy are the stimulation of the antioxidant defense system, hypoxia reduction and metabolism activation, including carbohydrate and lipid metabolism, and improving blood circulation. Currently papers devoted to the application of ozone in ophthalmology in treatment of age-related macular degeneration, viral conjunctivitis and keratitis, corneal degenerations, purulent corneal ulcer, pigmentary retinal degeneration, optic neuritis and atrophy, degenerative changes of the choroid, high myopia, hemophthalmia, rhegmatogenous retinal detachment, diabetic retinopathy are known.

Characteristics of corneal topographic and pachymetric patterns in patients with pellucid marginal corneal degeneration

To determine the characteristics of the shape of the cornea in patients with pellucid marginal corneal degeneration (PMD) and to compare these characteristics to those of eyes with keratoconus and eyes of normal subjects. This was a retrospective, cross-sectional case-series in which 49 eyes of 33 patients with PMD, 51 eyes of 51 patients with keratoconus and 53 eyes of 53 subjects with normal corneas (controls) were examined and compared. For all eyes, we obtained the topographic patterns of the axial power maps, anterior and posterior elevation maps and pachymetric maps using a rotating Scheimpflug camera. The eyes were classified into the respective patterns by visual inspection of these maps. In eyes with PMD, the most common axial power map pattern was the crab claw pattern (78 %) followed by the inferior steepening pattern (18 %). In eyes with keratoconus, the most common pattern was the inferior steepening pattern (67 %). The most common pattern in the elevation maps for both surfaces was the asymmetric island in eyes with PMD and keratoconus. Although the decentered pattern, including the decentered oval (27 %) and decentered round (20 %) pattern, on pachymetric map was specific to eyes with PMD, the incidence of these patterns was relatively low. The similarity in the topographic and pachymetric patterns in eyes with PMD and keratoconus suggests that they may be a continuity of the same disorder with different phenotypes.

Combined Tissue Excision and Corneal Tuck for the Surgical Treatment of Extremely Advanced Pellucid Marginal Corneal Degeneration

Pellucid marginal corneal degeneration (PMCD) is managed surgically in the advanced stages of the disease, but extreme thinning extending over a very wide area in most of the corneal circumference represents a true surgical challenge that makes conventional approaches unsuitable. Here, we present the results of a new procedure (partial excision of the corneal ectasia and tuck of the residual thinned corneal lips left behind) performed in 3 eyes of 2 patients with extremely advanced PMCD, judged unsuitable for undergoing conventional surgical approaches. Preoperatively, uncorrected visual acuity was limited to the perception of hand motion in 1 eye, which presented with hydrops, and to finger counting at 1 m in the other 2 eyes. With a follow-up of 3 to 4 years, a complete, stable resolution of the ectasia was seen in all cases. As early as 1 year postoperatively, the best spectacle-corrected visual acuity was 20/30 to 20/50 with no subsequent substantial changes. Partial excision of the ectasia and tucking was found to work successfully at achieving both a new corneal shape compatible with visual rehabilitation and restoring peripheral corneal thickness in advanced cases of PMCD that were unsuitable for conventional surgery.

Dietary α-Lipoic Acid Prevents UVB-Induced Corneal and Conjunctival Degeneration Through Multiple Effects

This study investigated the effects of dietary α-lipoic acid (α-LA) against ultraviolet B (UVB)-induced corneal and conjunctival degeneration in a mouse model. Female CBA mice were randomly divided into five study groups, including blank control, UVB without α-LA, and UVB with dietary α-LA at 1, 10, and 100 mg/kg body weight. Following UVB exposure, corneal surfaces were assessed along with immunohistochemistry for nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), malondialdehyde (MDA) accumulation, and P63⁺ basal cell distribution. Matrix metalloproteinase (MMP)-2 and MMP-9 activities were determined by gelatin zymography. ELISA assay was performed to confirm the findings of immunohistochemistry for NF-κB, COX-2, and MDA, along with the levels of TNF-α and IL-6. Tear production and goblet cell density were determined after tear strip assay and periodic acid Schiff staining, respectively. The results showed that UVB irradiation caused corneal surface damage, polymorphonuclear leukocyte infiltration, and loss of P63⁺ basal cells. Dietary α-LA ameliorated the UVB-induced corneal damage while simultaneously reducing MDA accumulation and maintaining P63⁺ basal cell survival. NF-κB-p65, COX-2, TNF-α, IL-6, and MMP-9 activity were all reduced by dietary α-LA. In addition, α-LA helped to reverse aqueous tear reduction, conjunctival squamous epithelium metaplasia, and goblet cell loss after UVB exposure. Dietary α-LA can prevent UVB-induced corneal damage and can be used as a prophylactic agent prior to excessive UVB exposure.

Structural, Morphological, and Functional Correlates of Corneal Endothelial Toxicity Following Corneal Exposure to Sulfur Mustard Vapor

Sulfur mustard (SM) is a highly reactive vesicant that causes severe ocular injuries. Following exposure to moderate or high doses, a subset of victims develops a chronic injury known as mustard gas keratopathy (MGK) involving a keratitis of unknown etiopathogenesis with secondary keratopathies such as persistent epithelial lesions, corneal neovascularization, and progressive corneal degeneration. This study was designed to determine whether SM exposure evokes acute endothelial toxicity and to determine whether endothelial pathologies were specifically observed in MGK corneas as opposed to healed corneas. Corneas of New Zealand white rabbits were exposed to SM vapor, and the corneal endothelium was evaluated at 1 day and 8 weeks using scanning electron microscopy (SEM), transmission electron microscopy (TEM), in vivo confocal microscopy (IVM), and fluorescent microscopy. Barrier function was measured by uptake of a fluorescent dye injected into the anterior chamber. A centripetal endothelial injury at 1 day was observed by SEM, TEM, IVM, and fluorescent microscopy. In vivo confocal microscopy revealed additional cytotoxicity between 1 and 13 days. In contrast to healed corneas, which appeared similar to sham-exposed naive eyes at 8 weeks, MGK corneas exhibited significant evidence of continued pathological changes in the endothelium. Endothelial toxicity occurs at the right time and with the appropriate pathophysiology to contribute to MGK. Based on these findings, we propose a model that explains the relationships among SM dose, the biphasic progression, and the various clinical trajectories of corneal SM injury and that provides a mechanism for temporal variations in MGK onset. Finally, we discuss the implications for the management of SM casualties.

Neues zur Biomechanik der Kornea beim Keratokonus

Keratoconus is a bilateral, progressive, non-inflammatory corneal degeneration characterized by a conical protrusion of the cornea which leads to marked corneal thinning thereby inducing severe visual impairment due to increasingly irregular astigmatism. Current corneal imaging technology provides an accurate anatomical and topographical analysis of the cornea which is the 'gold standard for the diagnosis of keratoconus and preoperative screening in refractive surgery. Until recently evaluation of corneal biomechanics was feasible only in vitro as the technology required for in vivo analysis was not available. However, in recent years methods have been developed which enable an accurate in vivo analysis of corneal biomechanics thereby enhancing the early detection of keratoconus and improving the safety profile of corneal refractive procedures.

Spontaneous Bleb Formation in a Presumed Pellucid Marginal Corneal Degeneration With Acute Hydrops

To report a case of spontaneous bleb formation in a presumed pellucid marginal corneal degeneration with acute hydrops. A 51-year-old man reported sudden ocular pain with a lower conjunctival mass in his left eye. A clinical examination was performed to investigate this lesion. The intraocular pressure in the left eye was markedly lower compared with that in the opposite eye. Slit-lamp examination of the left eye showed a conjunctival mass inferior to the corneoscleral limbus adjacent to corneal epithelial and stromal edema without perforation. Corneal topography showed the typical bow tie appearance of corneal steepening rotated 120 degrees clockwise. The right eye was totally normal. Fourier-domain optical coherence tomography with a corneal anterior module adaptor clearly showed a break in Descemet membrane and a ruptured corneal stromal cleft under the conjunctiva near the corneal limbus that resulted in spontaneous bleb formation. The cornea gradually healed after bandage treatment; the spontaneous bleb became smaller and the corneal stromal cleft and edema regressed at 3 months with corneal scarring. The intraocular pressure in the left eye recovered to the same level as that in the opposite eye in association with the decreased bleb size. This case indicated that spontaneous bleb formation in a pellucid marginal corneal degeneration should be included in the differential diagnosis of a conjunctival mass of unknown origin.

Corneal thickness measured by Scheimpflug imaging in children with Down syndrome

To measure corneal thickness via the use of a Scheimpflug imaging system (OCULUS Optikgeräte GmbH, Wetzlar, Germany) in children with Down syndrome. This prospective, nonrandomized, clinical trial included children with Down syndrome and age- and sex-matched healthy controls. All subjects received a complete ophthalmologic examination. Corneal topography measurements were acquired by means of Scheimpflug imaging. Central corneal thickness (CCT), thinnest point of cornea (TP), and corneal volume (CV) were analyzed. A total of 27 children with Down syndrome and 37 control subjects were included in the study. In children with Down syndrome, the mean CCT was 494.27 ± 47 μm, the mean TP was 487 ± 49 μm, and the mean CV was 56.2 ± 6. In the controls, the mean CCT was 539.3 ± 40 μm, the mean TP was 538.0 ± 40.8 μm, and the mean CV was 61.3 ± 4. For all 3 parameters, the difference was statistically significant (P < 0.001). In the Down syndrome group, the CCT was <500 μm in 16 subjects (59.2%) and <450 μm in 5 (18.5%). In the control group, the CCT was <500 μm in 14 subjects (37.8%) and <450 μm in 2 (5.4%). In this study, corneal thickness was less in children with Down syndrome than in healthy control subjects. Decreased corneal thickness may be an early sign of a degenerative corneal disease such as keratoconus in children with Down syndrome.

Three hundred and sixty degree retinotomy for retinal detachments with severe proliferative vitreoretinopathy

To assess the anatomic and functional results of 360° retinotomy for rhegmatogenous retinal detachment (RD) with severe proliferative vitreoretinopathy (PVR). Retrospective, non-comparative, interventional, case study of 20 consecutive patients. All surgical operations are as follows: vitrectomy, membrane peeling, PFCL, circumferential 360° retinotomy with anterior retinectomy, and silicone oil tamponade. The decision to pursue retinotomy was made during surgery after exploring all conventional techniques and after maximum membrane removal. The mean number of previous interventions was 1.7 (median 2; range: 0-4). All retinas were reattached at the end of surgery. After 38 months of mean follow-up (range: 18-53 months) the complete retinal reattachment rate was 70 % (14/20). At the end of follow-up, four eyes (20 %) were enucleated and two patients are deceased. Silicone oil was removed in five eyes (25 %). Five eyes (25 %) developed corneal degeneration, four (20 %) rubeosis and one eye (5 %) presented an optic nerve atrophy. Final post-operative visual acuity in eyes with reattached retinas (n = 14) was better or equal to 20/200 in two cases, counting fingers in six cases , hand movements in five cases and light perception in one case. Only two of 20 operated eyes (10 %) had visual acuity better or equal to 20/200, but only four eyes (20 %) were enucleated. The aim of 360° retinotomy is to avoid further surgery on already fragile and multi-operated eyes.

Peripheral Hypertrophic Subepithelial Corneal Degeneration: Nomenclature, Phenotypes, and Long-Term Outcomes

To describe the long-term outcomes of peripheral hypertrophic subepithelial corneal degeneration. Retrospective case series. Twenty-two patients under the care of the External Disease Service, Moorfields Eye Hospital. All patients matching clinical diagnostic criteria were included. Symptomatic patients were managed either conservatively or were offered superficial keratectomy in progressive cases where symptom control was inadequate. All excised tissue was examined histologically. Clinical phenotype, symptoms, recurrence rate after surgery, and histopathologic results. Twenty-two white patients (20 women and 2 men; age range, 27-88 years; median age, 42 years) had peripheral, usually bilateral (20/22 [91%]), elevated circumferential peripheral subepithelial corneal opacities and adjacent abnormal limbal vasculature, with or without pseudopterygia in 9 patients (41%), among whom 7 (32%) patients had bilateral disease. Apart from the abnormal vasculature, there were no signs of chronic ocular surface inflammation. Symptoms were ocular surface discomfort in 10 patients (45%), reduced vision in 4 patients (18%), and both of these in 5 patients (23%). Three patients (14%) were asymptomatic. There was no treatment in 6 patients (27%), topical lubricants in 8 patients (36%), spectacles in 1 patient (5%), and superficial keratectomy in 7 patients (32%; 5 bilateral), which was repeated for incomplete primary excision in 1 eye of 2 patients (9%) and for a bilateral recurrence in 1 patient (5%). Median follow-up after excision was 5 years (range, 1-11 years). Histopathologic changes were similar to those observed in pterygia (vascular component) and Salzmann's nodular degeneration (corneal component). Peripheral hypertrophic subepithelial corneal degeneration is an uncommon, usually bilateral, idiopathic disorder, occurring mostly in white women with a distinct phenotype. The condition was first described in 2003. Further cases among some patients have been described in more recent case series of Salzmann's nodular degeneration and diffuse keratoconjunctival proliferation, as well as in the previously described familial pterygoid corneal degeneration. Surgical excision was required in 30% of patients in this series, with infrequent short-term recurrences. The cause is uncertain. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Peripheral hypertrophic subepithelial corneal degeneration: characterization, treatment and association with human leucocyte antigen genes

To evaluate the efficacy of keratectomy in treating irregular astigmatism caused by peripheral hypertrophic subepithelial corneal degeneration (PHSD) and to study the possible underlying immunological risk factors. Patients (14 eyes) with diagnosed PHSD were treated with superficial keratectomy with or without the assistance of phototherapeutic keratectomy (VisX S4; VisX Inc., Santa Ana, CA, USA). Thirteen patients were subjected to analysis of human leucocyte antigen (HLA) genes, complement C4 gene numbers and total plasma immunoglobulin levels. Immunological risk factors between patients and a control group comprising 150 individuals were compared. The mean preoperative best spectacle corrected visual acuity (BCVA) improved from 0.16 ± 0.22 (LogMAR scale range 0-0.7) to 0.06 ± 0.13 (-0.1-0.4) (p < 0.01). The mean preoperative astigmatism decreased significantly from 3.8 ± 2.1 D (range 1.2-8.2) to 2.1 ± 1.4 (range 0.6-5.0, p = 0.02) based on corneal topography. The HLA-B*44 allele and the ancestral haplotype (AH) 8.1 were found significantly more often in PHSD patients than in controls (both p = 0.03). No differences in the C4 genes were found. Astigmatism secondary to PHSD can be effectively treated with keratectomy. Peeling of the fibrotic tissue reduced astigmatism and improved visual performance. We suggest that HLA-B*44 allele and AH 8.1 haplotype are immunological factors predisposing to the development of PHSD. The consequent disruption/alteration of the limbal barrier may lead to corneal peripheral fibrous formation inducing astigmatism.