Optimization of Diagnosis and Surgical Treatment of Involutional Entropion of the Lower Eyelid

Background: Rolling inwards of the lid margin is called entropion, and is produced by a disparity in length and tone between the anterior skin muscle, and posterior tarso-conjunctival laminae of the eyelid. Involutional, cicatricial, spastic, or congenital are some of the classifications involutional entropion there is general instability of the lid structures with age .A weakness of the posterior retractors of the lid occurs, together with a laxity of the medial and lateral canthal ligaments, accompanied by a loss of posterior support ,as atrophy of the orbital fat leads to enophthalmos. The current treatment modalities for this condition are surgical in nature, although non-surgical temporary medical treatment are also used. It's a commonest types of eyelid asymmetry. Corneal and conjunctival damage may lead to abrasions, scarring, corneal thinning, or corneal neovascularization due to this misalignment. Unilateral or bilateral entropion is possible. Involutional entropion of lower eyelids are common, but cicatricial upper eyelids are common. Entropion of lower eyelid is a much more prevalent than entropion of the upper eyelid. Objective: The purpose is to review the scientific literature on diagnosis and surgical management of involutional entropion of the lower eyelid. Methodology: The data were collected from the various electronic data bases like google scholar, PubMed and various books. Conclusion: After reviewing the articles, we come to the conclusion that the signs and symptoms of involutional entropion are easily manageable by given treatment.

A Clinical Case of Fitting Scleral Lens for Correction of Pellucid Marginal Degeneration

Background. Pellucid Marginal Degeneration (PMD) is a rare bilateral degenerative corneal disease. It causes corneal ectasia with bilateral, clear, inferior (typically 4 o’clock to 8 o’clock), peripheral corneal thinning. It usually affects about 80% of corneal stroma, which leads to the corneal ectasia above the thinning area as well as provokes the irregular astigmatism and visual impairment that are difficult to correct. Purpose. To study the possibilities of correction and social rehabilitation in a patient with PMD wearing scleral lenses. Materials and methods. The study included a patient with PMD, signs of corneal dysfunction and narrow-angle subcompensated glaucoma in the right eye, and PMD of the cornea resulted in a corneal leukoma – terminal glaucoma in the left eye. In addition to standard ophthalmic methods, we performed corneal topography and optical coherence tomography (OCT). For intraocular pressure measurement, ICARE IOP tonometer was used in several areas of the intact peripheral cornea. Results. Prior to lens fitting, UCVA in the right eye amounted to 0.06. Scleral lens helped achieve a high visual acuity of 0.9–1.0. The lens was well-tolerated by the patient. Conclusion. Scleral lenses may be a good choice for patients with irregular cornea caused by corneal dystrophy. Not only they are easy to use and have a good visual effect, but they also help patients with social rehabilitation.

A Mouse Model of Brittle Cornea Syndrome caused by mutation in Zfp469

Brittle Cornea Syndrome (BCS) is a rare recessive condition characterised by extreme thinning of the cornea and sclera. BCS results from loss-of-function mutations in the poorly understood genes ZNF469 or PRDM5. In order to determine the function of ZNF469 and to elucidate pathogenic mechanisms, we used genome editing to recapitulate a human ZNF469 BCS mutation in the orthologous mouse gene, Zfp469. Ophthalmic phenotyping showed that homozygous Zfp469 mutation causes significant central and peripheral corneal thinning arising from reduced stromal thickness. Expression of key components of the corneal stroma in primary keratocytes from Zfp469BCS/BCS mice is affected, including decreased Col1a1 and Col1a2 expression. This alters the type I:type V collagen ratio and results in collagen fibrils with smaller diameter and increased fibril density in homozygous mutant corneas, correlating with decreased biomechanical strength in the cornea. Cell-derived matrices generated by primary keratocytes show reduced deposition of type I collagen offering an in vitro model for stromal dysfunction. Work remains to determine whether modulating ZNF469 activity will have therapeutic benefit in BCS or in conditions such as keratoconus where the cornea thins progressively.

A Mouse Model of Brittle Cornea Syndrome caused by mutation in Zfp469.

Brittle Cornea Syndrome (BCS) is a rare recessive condition characterised by extreme thinning of the cornea and sclera. BCS results from loss-of-function mutations in the poorly understood genes ZNF469 or PRDM5. In order to determine the function of ZNF469 and to elucidate pathogenic mechanisms, we used genome editing to recapitulate a human ZNF469 BCS mutation in the orthologous mouse gene, Zfp469. Ophthalmic phenotyping showed that homozygous Zfp469 mutation causes significant central and peripheral corneal thinning arising from reduced stromal thickness. Expression of key components of the corneal stroma in primary keratocytes from Zfp469BCS/BCS mice is affected, including decreased Col1a1 and Col1a2 expression. This alters the type I:type V collagen ratio and results in collagen fibrils with smaller diameter and increased fibril density in homozygous mutant corneas, correlating with decreased biomechanical strength in the cornea. Cell-derived matrices generated by primary keratocytes show reduced deposition of type I collagen offering an in vitro model for stromal dysfunction. Work remains to determine whether modulating ZNF469 activity will have therapeutic benefit in BCS or in conditions such as keratoconus where the cornea thins progressively.

Comparison of Amsler–Krumeich and Sandali Classifications for Staging Eyes with Keratoconus

Keratoconus (KC) is the most common corneal ectasia characterized by progressive corneal thinning, protrusion, and irregular astigmatism. The Amsler–Krumeich classification based on the analysis of corneal topography, corneal thickness, refraction and biomicroscopy is the most commonly used; recently, a new classification based on anterior segment Optical Coherence Tomography was introduced by Sandali and colleagues. Since there is no information about the possible agreement between these two classifications, the aim of this study is to compare the stratification of consecutive KC patients using the Amsler–Krumeich and Sandali classifications, and to further ascertain KC cases in which one classification is preferred over the other. Overall, 252 eyes of 137 patients (41.45 ± 16.93 years) were analyzed: in 156 eyes (61.9%), the Amsler and Sandali staging differed in one stage while in 75 cases (29.8%) it differed in two or more stages. In 222 eyes (88.1%), the Sandali staging was higher compared to the Amsler one. These results show that the two classifications are not fully interchangeable: the Amsler–Krumeich classification is more appropriate in identifying and longitudinally monitoring patients with early stages of KC, while the Sandali classification for the diagnosis and follow-up of patients with more advanced stages, particularly when a surgical planning has to be chosen.

Quantitative comparison of corneal surface areas in keratoconus and normal eyes

Keratoconus is a highly prevalent corneal disorder characterized by progressive corneal thinning, steepening and irregular astigmatism. To date, pathophysiology of keratoconus development and progression remains debated. In this study, we retrospectively analysed topographic elevation maps from 3227 eyes of 3227 patients (969 keratoconus and 2258 normal eyes) to calculate anterior and posterior corneal surface area. We compared results from normal eyes and keratoconus eyes using the Mann–Whitney U test. The Kruskal–Wallis test was used to compare keratoconus stages according to the Amsler–Krumeich classification. Keratoconus eyes were shown to have statistically significantly larger corneal surface areas, measured at the central 4.0 mm and 8.0 mm, and total corneal diameter. However, no significant increase in corneal surface area was seen with increasing severity of keratoconus. We suggest that these results indicate redistribution, rather than increase, of the corneal surface area with keratoconus severity.

Risk factors and evaluation of keratoconus progression after penetrating keratoplasty with anterior segment optical coherence tomography

To determine the risk factors and unique characteristics of keratoconus (KC) progression after penetrating keratoplasty (PK), anterior segment optical coherence tomography parameters were statistically analyzed in comparison with eyes undergoing PK for other diseases as a control. Ninety-one eyes maintaining clear PK grafts for over 10 years were divided into 2 groups according to the primary indication for PK (KC vs Others groups). Corneal thinning indicators (inferior host thinnest corneal thickness/central corneal thickness [IHT/CCT], inferior graft thinnest corneal thickness/CCT [IGT/CCT]), were smaller whereas anterior chamber depth, and steepest corneal power (Ks), and maximum corneal power (Kmax) were larger in the KC group with statistical significance. Graft size, Kmax and Ks correlated with IHT/CCT and IGT/CCT in the KC group. These correlations were not detected in controls. Graft size and postoperative period were selected by multivariate regression analysis as factors for corneal ectatic changes in the KC group. In conclusion, KC eyes long after PK show inferior graft and host corneal thinning, and corneal protrusion. Corneal power parameters such as Kmax or Ks can be used to monitor KC progression after PK. A small graft might lead to KC progression after PK.

Peripheral Ulcerative Keratitis in a Patient with Bilateral Scleritis: Medical and Surgical Management

Peripheral ulcerative keratitis (PUK) is a group of corneal disorders that cause peripheral corneal thinning, threatening globe integrity in advance stages. It is usually associated with systemic autoimmune diseases and management is based on local and systemic approaches. We present the case of a 47-year-old man with a previous history of bacterial keratitis in his left eye presenting with 1 month of bilateral ocular pain and redness. At examination, diffuse bilateral globe inflammation with paracentral corneal thinning in his left eye was observed. He was diagnosed with bilateral scleritis and PUK in his left eye. Workup for associated systemic autoimmune disease yielded negative results. The patient was started on pulses of intravenous methylprednisolone followed by oral prednisone failing to achieve sufficient control of the inflammatory syndrome. Subsequently, periodic intravenous cyclophosphamide was administered with a favorable response. A multilayer amniotic membrane graft was applied, but there was rapid melting with reabsorption of the tissue, resulting in extreme corneal thinning at the inferior paracentral cornea. A decentered 8.5-mm superficial anterior lamellar keratoplasty (SALK) was then performed obtaining the donor graft with a femtosecond laser but performing manual trepanation in the recipient. At 12 months, visual and biomicroscopic measures do not show deterioration and inflammation remains under control with oral azathioprine as maintenance regime. The management of PUK includes both systemic immunosuppression and tectonic procedures to preserve the globe integrity. Diverse surgical techniques have been attempted, but no definitive guidelines are available. Decentered large SALK is a simple technique that can yield acceptable visual results.