Evaluation of ocular surface impairment in meibomian gland dysfunction of varying severity using a comprehensive grading scale

This study aimed to propose a comprehensive grading scale to evaluate different clinical manifestations in patients with varying severity of meibomian gland dysfunction (MGD) and analyze the correlations between the parameters of ocular surface impairment in MGD.A total of 63 patients with MGD were enrolled. Ten specific symptoms were evaluated each with a subjective score and total score was applied to grade the severity of MGD. Thirty-seven patients were diagnosed with mild, 19 with moderate, and 7 with severe MGD. Slit-lamp and keratography were used to assess the signs of ocular surface and meibomian gland (MG). In vivo confocal microscopy (IVCM) was performed to evaluate the corneal nerves and dendritic cells. The differences and correlations between symptoms, signs, and IVCM parameters were analyzed.Dryness, foreign body sensation, asthenopia, and photophobia were the most common and severe symptoms in our patients. The severe MGD group showed worse MG expressibility, Meibum score, Meiboscore, MG score, and higher nerve reflectivity (P < .05). The mild MGD group showed higher nerve density (P < .05). Total symptom score was negatively correlated with nerve density (r = -0.374, P < .05), while positively correlated with nerve reflectivity and dendritic cell density (r = 0.332 and 0.288, respectively, P < .05). MG score was correlated with nerve reflectivity (r = 0.265, P < .05).The comprehensive grading scale was suitable for evaluating clinical manifestations in MGD of varying severity. The relationship between the specific symptoms, signs, and IVCM results concerning whole ocular surface impairment could help elucidate MGD pathophysiology and benefit evaluation or treatment in the future.

Corneal Epithelial Cell Fate Is Maintained during Repair by Notch1 Signaling via the Regulation of Vitamin A Metabolism

Integrity and preservation of a transparent cornea are essential for good vision. The corneal epithelium is stratified and nonkeratinized and is maintained and repaired by corneal stem cells. Here we demonstrate that Notch1 signaling is essential for cell fate maintenance of corneal epithelium during repair. Inducible ablation of Notch1 in the cornea combined with mechanical wounding show that Notch1-deficient corneal progenitor cells differentiate into a hyperplastic, keratinized, skin-like epithelium. This cell fate switch leads to corneal blindness and involves cell nonautonomous processes, characterized by secretion of fibroblast growth factor-2 (FGF-2) through Notch1(-/-) epithelium followed by vascularization and remodeling of the underlying stroma. Vitamin A deficiency is known to induce a similar corneal defect in humans (severe xerophthalmia). Accordingly, we found that Notch1 signaling is linked to vitamin A metabolism by regulating the expression of cellular retinol binding protein 1 (CRBP1), required to generate a pool of intracellular retinol.

[Anhidrotic ectodermal dysplasia: "congenital ameibomia"]

Anhidrotic ectodermal dysplasia is a congenital, generally X-linked dermatosis that associates facial dysmorphy, short stature, and severe blepharitis. The anomalies of the skin are epidermic abnormalities; reduction of the glands of the derm, particularly the sweat glands, explaining the hypohidrosis; onychodysplasia; trichodysplasia; and abnormal dentition. The ophthalmologic manifestations are palpebral anomalies with a reduction in or an absence of Meibomian glands, dysfunction of the Moll and Zeis glands, leading to chronic squamous blepharitis and lacrimal punctal atresia. These anomalies result in severe attacks of the ocular surface, developing during the second decade, which are often invalidating and require a rigorous follow-up to avoid corneal complications.

Increased Tear Evaporation in a Patient with Ectrodactyly-Ectodermal Dysplasia-Clefting Syndrome

PURPOSE

To describe the tear function and ocular surface disorders in a patient with ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome.

METHODS

Routine ophthalmic examinations were performed, including slit-lamp biomicroscopy, anterior segment photography including transillumination photos of the lids, Schirmer tests I and II, tear film break-up time (BUT) assessment, corneal fluorescein staining, DR-1 tear film lipid layer interferometry, and tear evaporation rate measurements.

RESULTS

Slit-lamp examination revealed conjunctival hyperemia, superficial punctate keratopathy, and corneal leucoma with neovascularization. Although the Schirmer test values were within normal limits, the BUT value was 0 s in both eyes. Transillumination of the lids showed the absence of meibomian glandular structures. DR-1 tear film lipid layer interferometry results were dry eye grade 5 with an irregular tear film, areas of corneal surface exposure, and several dry spots. The tear evaporation rate was elevated and was measured as 6.98 x 10(-7) g/cm2 per second (normal, 4.1 +/- 1.4 x 10(-7) g/cm2 per second).

CONCLUSION

The ocular surface disorder and shortened BUT in EEC syndrome were attributed to the absence of meibomian glands, leading to lipid layer deficiency in the tear film with a concomitant increase in tear evaporation.

Ophthalmic manifestations of ectrodactyly-ectodermal dysplasia-clefting syndrome

Ophthalmic manifestations are a common component of the ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome; however, few ophthalmic publications have specifically addressed these features. The authors describe a 38-year-old patient with EEC syndrome who demonstrated several associated ocular signs and symptoms. The ophthalmic findings in this patient included bilateral entropion with secondary trichiasis, and shallow inferior fornices with symblepharon. Interestingly, the patient also had vertically deficient tarsi and absence of the meibomian glands. Ophthalmologists should be aware of the ocular signs and symptoms associated with EEC because some manifestations can potentially be sight threatening.

Ocular manifestations in a father and son with EEC syndrome

BACKGROUND

The ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome is a rare disease which follows an autosomal-dominant pattern of inheritance. Due to the ectodermal dysplasia there is atresia of the lacrimal duct system and aplasia of the meibomian glands with a defective tear film. Therefore, vascularized corneal scars often form during early adult life.

PATIENTS

Father aged 41 years, and son aged 23 months. Both patients: stenosis/atresia of lacrimal duct systems (the father had twice undergone dacryocystorhinostomy externally) with epiphora, lip-palate clefting, syndactylies of fingers and toes, lobster deformities of hands. Additional ophthalmological findings in the father: bilaterally extracted juvenile cataracts with implantation of intraocular lenses, bilateral extensive vascularized corneal scars. Additional dermatological findings in the father: malignant melanoma of the calf, now in complete remission following several operations on the melanoma and several cycles of chemotherapy for the metastases.

DISCUSSION AND THERAPEUTIC CONCLUSIONS

Father and son show the full clinical picture of the EEC syndrome with clefting, lobster-like deformities of the hands and ectodermal dysplasia with tear duct atresia and aplasia of the meibomian glands with defective tear film. During childhood, the main handicapping features are the clefting and the hand deformities with their respective multiple operative revisions. During early adulthood, however, the ocular problems become the predominantly handicapping aspects of the EEC syndrome; due to the ectodermal dysplasia, vascularized corneal scarring develops. Tearing and secondary inflammation due to lacrimal duct atresia has to be treated by early dacryocystorhinostomy. As secondary infections promote the development of corneal scars, one should not postpone the operation too long. Infections have to be treated promptly by local antibiotics. Because of the aplasia of the meibomian glands, artificial tear substitution should be given on a regular basis to support the defective tear film. Thus, the development of vascularized corneal scars can perhaps be delayed. Once corneal scarring has developed, perforating keratoplasty has a poor prognosis due to the ectodermal dysplasia, the absence of the meibomian glands and the defective tear film. Three factors lead to the formation of vascularized corneal scars: recurrent infections of lid margins and conjunctiva due to obstructed tear ducts; defective tear film with insufficient lipid phase due to the aplasia of the meibomian glands; and primary corneal epithelial defects in the course of the generalized ectodermal dysplasia.

Absent meibomian glands: a marker for EEC syndrome

A patient with a 20 year history of severe keratoconjunctivitis of unknown origin was found, on assessment at a blepharitis clinic, to have complete absence of meibomian glands. Further examination revealed the features of EEC syndrome. To our knowledge, this is the only case to have been diagnosed in this way. The ocular complications of EEC syndrome and other ectodermal dysplasias are reviewed.

Congenital deficiency of meibomian glands

A 16-year-old girl presented with contact lens intolerance. She was found to have a marked deficiency of meibomian glands in the upper lids and almost total absence in the lower lids. Evidence of tear film instability was found and attributed to deficient lid oil production. A daily wear soft contact lens was later fitted and tolerated.

Absent meibomian glands in the ectrodactyly, ectodermal dysplasia, cleft lip-palate syndrome

A 27-year-old woman with the syndrome characterized by ectrodactyly, ectodermal dysplasia, and cleft lip-palate had an absent lacrimal punctum in each eye, with signs and symptoms of nasolacrimal obstruction during childhood. Examination disclosed bilateral corneal vascularization and opacification, with diffuse superficial punctate staining of the ocular surface epithelium by fluorescein, an instantaneous tear film break-up time, and normal Schirmer tear measurements. A full-thickness biopsy specimen of the eyelid confirmed the absence of meibomian glands that had been suspected because of absent meibomian gland orifices and secretions. The total absence of meibomian gland secretions in this patient may be a primary feature of this case and may contribute to a lipid-deficient and unstable tear film with resultant desiccation and destruction of the ocular surface epithelium. Breakdown of the corneal epithelium in association with obstruction and infection of the nasolacrimal system may be a particularly disastrous combination for the cornea that resulted in the recurrent, severe bacterial corneal ulcers found in our patient.

Lid splitting and posterior lamella cryosurgery for congenital and acquired distichiasis

Congenital distichiasis is a rare condition with an accessory row of lashes at the Meibomian gland orifices. We suggest "acquired distichiasis" as an appropriate term for the accessory row of lashes in or near the Meibomian gland orifices, occurring as a result of such conditions as Stevens-Johnson syndrome, ocular pemphigoid, or chemical and physical injuries. We report a new treatment technique in which the eyelid is divided along the gray line then followed by cryotherapy to the posterior lid lamella. This removes the distichiatic lashes without damaging the normal lashes in the anterior lid lamella and avoids depigmentation. Histologic examination demonstrates the aberrant lashes result from a metaplasia of tissues in or around the Meibomian glands. Thirteen eyelids with acquired distichiasis and four eyelids with congenital distichiasis have been followed up for eight to 48 months. All have been greatly improved.

Congenital euryblepharon

Three cases of congenital euryblepharon are presented. In these cases, horizontal width of the eyelid margin is abnormally increased in comparison to the globe and orbit. The 3 cases were all different. One case had involvement of all 4 lids. Another had unilateral involvement of upper and lower eyelids. A third case had bilateral lower lid involvement associated with other anomalies. The additional anomalies which have not been previously reported include a double row of meibomian gland orifices and an extreme lateral displacement of the lower canaliculus and punctum. All cases had varying degrees of vertical shortage of skin in the involved lids leading to lagophthalmos with a mild to moderate exposure keratitis. A review of previously reported cases of euryblepharon is made. The types of surgical procedures used to correct the deformities are discussed.

Distichiasis of the lids and lymphedema of the lower extremities: a report of ten cases

Ten members belonging to two different families were affected by distichiasis of the lids (double row of eyelashes) and lymphedema of the lower extremities. Other less frequent congenital anomalies, such as pterygium colli and ptosis were found in some affected members. The previously reported cases were reviewed. A single pleiotropic gene with a high penetrance and a variable expressivity is responsbile for the different anomalies of this dominantly inherited syndrome.