Blepharophimosis is an ophthalmic syndrome manifested by bilateral ptosis in combination with a decrease in the vertical and horizontal size of the eyelids. The main symptoms are: pathological eye incision, increased fatigue when performing visual work, visual impairment, impaired accommodation. To make a diagnosis, physical examination, ultrasound of the eye, biomicroscopy, visometry, non-contact tonometry are used. Treatment tactics are reduced to operative multi-stage reconstruction of the eyelids, including canthoplasty with subsequent correction of ptosis.
General information
Blepharophimosis is one of the forms of eyelid dysplasia, first described in 1889 by the French ophthalmologist Vinh. Sporadic forms of pathology are observed in 55% of cases. It is possible to identify genetic mutations or establish a hereditary predisposition using the genealogical method only in 45% of patients. Male and female individuals get sick with the same frequency. The disease is more often diagnosed in residents of North, East and Southeast Asia, which is due to national peculiarities of appearance. There are no statistical data on the general prevalence of blepharophimosis in ophthalmology.
Causes
The etiology of the disease is not fully understood. The disease can develop in isolation or be detected in the structure of genetic pathologies (Schilbach-Rott syndrome, mouth-face-finger syndrome). Blepharophimosis can often be diagnosed in other family members, which indicates its hereditary nature. Triggering factors are:
- Teratogenic effects. The most pronounced embryotoxic effect is caused by the intake of alcoholic beverages, smoking, and the consumption of narcotic drugs during pregnancy. All of the above contributes to the occurrence of sporadic mutations.
- Taking medications. Eye defects are often caused by the use of medications by pregnant women that affect the formation of the eyeball. These include warfarin, antipsychotics, narcotic analgesics, sympathomimetics, and nervous system stimulants.
- Infectious diseases. The onset of symptoms of the disease may be due to intrauterine infection with measles virus, rubella, herpes. Viral agents are able to penetrate the hematoplacental barrier and negatively affect the embryogenesis of the organ of vision.
- The influence of physical factors. The development of congenital blepharophimosis is provoked by radiation exposure. This is usually associated with X–ray diagnostics during pregnancy, less often with exposure to ionizing radiation at home or at work.
Pathogenesis
Blepharophimosis is a congenital, genetically determined pathology. The type of inheritance is autosomal dominant. Scientists associate the development of the disease with mutations of the FOXL2 gene, which is localized at 3q22.3-q23. The disease is characterized by the phenomenon of formation of pathological tissues in the orbital zone. The formation of adhesions leads to fusion of the palpebral edges, more often – lateral. The anomaly is formed in the first trimester of pregnancy, when the eyelid and eyeball are laid. The effect of teratogenic factors on the sixth month of fetal embryogenesis provokes a violation of the splitting of the frontonasal and maxillary processes on the lower and upper eyelid.
With intrauterine infection with herpes, rubella or measles viruses in genetically compromised individuals, the process of differentiation of eyeball structures is disrupted, this causes multiple malformations of the visual organ. Blepharophimosis syndrome is considered as one of the manifestations of myogenic, less often neurogenic ptosis. With the myogenic nature of the disease, eyelid dysplasia is combined with dystrophic changes in the circular muscle of the eye. Persons with neurogenic form have underdevelopment of the oculomotor nerve. At the same time, the innervation of the skin in the orbital region is disturbed.
Symptoms
The first symptoms of the disease are detected in the neonatal period. Parents pay attention to the unusual cut of the child’s eyes. The eye slit is not only excessively narrow, but also shortened. The deformation of the medial angle of the eye is visualized. In patients, the underdevelopment of the bridge of the nose is determined. The distance between the right and left eyeball is increased, which indicates hypertelorism. The distance between the inner corners of the eye slits is also increased. A vertical fold of the skin of a semilunar shape is found, located in the area of the lower eyelid. The upper eyelid is lowered. The closure of the eye slit is sharply limited.
Older patients complain of rapid eye fatigue with visual loads, excessive tearing, a feeling of a foreign body or “sand” under the eyelids. Due to the narrow orbital slit, the functioning of the accommodation apparatus is disrupted, which leads to visual dysfunction. In patients with a severe course of the disease, there is a lag in mental development. In the case of concomitant development of microphthalmos, visual acuity is reduced to complete blindness. Most patients have increased dryness of the eyes, often xerophthalmia is detected. Due to a cosmetic defect, social adaptation is disrupted.
Complications
The most common complication of blepharophimosis is ectropion of the eyelid. Patients are at risk of infectious complications of the anterior segment of the eye (conjunctivitis, keratitis, blepharitis). The pathology of eyelid closure and the defective structure of the tear film provoke the occurrence of dry eye syndrome. There is a high probability of inflammation of the nasolacrimal canal with the subsequent development of dacryocystitis. A defect in the bone wall of the eye socket leads to a relative elongation of the longitudinal axis of the eye and secondary hypermetropia. The exception is patients with microphthalmos.
Diagnostics
The diagnosis is based on the data of physical examination and specific techniques. Visually, a decrease in the size of the vertical and horizontal eye slits, ptosis, hypoplasia of the orbital edge of the bridge of the nose is determined. The degree of limitation of the mobility of the upper eyelid is measured. The following instrumental research methods are used:
- Visometry. The nature of visual dysfunction depends on the severity of the disease. In mild forms, visual acuity corresponds to the norm. With a complicated course, visual impairment can reach amaurosis.
- Biomicroscopy of the eye. Examination of the anterior segment of the eyeball reveals injection of conjunctival vessels and ulceration of the cornea. These changes are secondary in nature.
- Non-contact tonometry. In the anamnesis, patients have a violation of the secretion of watery moisture. In some cases, this leads to a decrease in intraocular pressure.
- Ultrasound of the eyes. Ultrasound examination reveals bilateral symmetrical hypoplasia of the upper parts of the eye socket. It is possible to visualize a decrease in the diameter of the eyeball, which indicates microphthalmia.
Differential diagnosis is performed with blepharochalasis and pseudoptosis. With blepharochalasis, the development of clinical symptoms is due to overhanging of the skin, the location of the upper eyelid is not changed. A distinctive feature of pseudoptosis is the secondary omission of the upper eyelid. The main etiological factor is eyeball hypotrophy, endophthalmos, strabismus.
Treatment
Treatment tactics depend on the anatomical features of the ocular slit and concomitant lesions, developed individually for each patient. As a rule, patients need multi-stage reconstruction. First of all, the correction of the telecanthus and the reverse epicanthus is shown. To do this, transnasal fixation or Z-plasty is performed. Next, canthoplasty is performed. The purpose of the surgical intervention is to correct the incision of the eyes. After the canthotomy, the canthal tendon is partially removed and the eyelid tissues are fixed to the periosteum of the orbit. A cosmetic suture is applied in the incision area.
If necessary, ptosis is corrected at the final stage of reconstruction. With a less pronounced cosmetic defect, they are limited to carrying out cantopexy. During the operation, the lateral palpebral corner is tightened. External sutures are removed 5-7 days after surgery. Less often, additional plastic surgery is performed on the medial part of the upper eyelid. The patient should be under the dynamic supervision of an ophthalmologist. If necessary, 3-6 months after the last operation, corrective plastic surgery of the position of the upper eyelid is performed.
Prognosis and prevention
Timely surgical intervention allows you to fully restore the functions of the eyelids, eliminate or minimize a cosmetic defect. Correction of visual dysfunction with concomitant microphthalmos is not possible. Specific prevention of blepharophimosis has not been developed. Non-specific preventive measures are based on the prevention of exposure to teratogenic factors (alcohol, ionizing radiation, narcotic drugs, etc.) during pregnancy. If there are cases of blepharophimosis in parents or close relatives, a geneticist’s consultation is necessary.