giant papillary conjunctivitis
Introduction
Introduction to giant papillary conjunctivitis Giant papillary conjunctivitis (GPC) is a non-infectious immune inflammatory response that mainly affects the upper conjunctiva. Named for the presence of "huge" nipples (diameter 1.0 mm) on the surface of the conjunctiva. basic knowledge The proportion of illness: 0.003% Susceptible people: no specific population Mode of infection: non-infectious Complications: conjunctival hyperemia
Cause
Cause of giant papillary conjunctivitis
(1) Causes of the disease
More with wearing hydrophilic contact lenses, glaucoma follicles, exposed corneal sutures, prosthetic eyes, scleral buckling and keratoconus lesions, termination of wearing glasses and after treatment can be cured.
(two) pathogenesis
1. Mechanical and depositional theory GPC is generally considered to be a disease associated with wearing contact lenses and ocular prostheses. It has recently been discovered that exposed corneal sutures and other protrusions (such as protruding scleral buckling) can also cause GPC. In this case, the blink frequency may exceed the normal frequency (about 20,000 times a day). Therefore, it is believed that the foreign body is mechanically wounded with the upper eyelid conjunctiva accompanied by blinking action.
Deposits on the surface of the contact lens can also cause eyelid trauma. Fowler et al found that the deposits of contact lenses worn by GPC patients exceeded 90% of the surface area of the contact lens, compared with only 5% of asymptomatic patients, especially soft contact lenses. It can accumulate deposits that even professional technicians can't clean. These deposits include: mucus, cell debris and bacteria. After cleaning the lens with a protein-removing preparation, the patient's symptoms can disappear and last for up to 2 months. (such as papain) can increase the tolerance to the lens after removing the protein, and the permeability of the lens material can also affect the incidence of GPC.
Recent studies have suggested that meibomian gland inflammation and meibomian gland dysfunction are also associated with GPC. One possibility is that meibomian gland dysfunction and its tear film instability and dry eye cause a common cause. The mechanical trauma of the lens to the conjunctiva, there is evidence that the lactoferrin concentration of tears in GPC patients decreases, this decline may promote the deposition of a large number of bacteria and their products in the lens, but also promote the occurrence of infection, especially Staphylococcal infection.
2. Type I hypersensitivity
Type I hypersensitivity may play a role in the pathogenesis of GPC, and it has been found that there is a close correlation between atopy and GPC.
As with other forms of allergic conjunctivitis, mast cells have been confirmed in the epithelial layer of GPC patients. Most of the mast cells are degranulated in histology, and Henriquez et al found 30% of the conjunctiva in GPC patients. Mast cells are in the degranulated state, while in VKC, 80%. The increase in free IgE levels in tears also suggests a type I hypersensitivity reaction, as mast cell degranulation is triggered by IgE cross-linking. A consistent phenomenon is the type of cell infiltration, infiltrating cells are eosinophils, basophils and neutrophils, which are inflammatory mediators released by mast cells and later released by inflammatory cytokines. Attraction, vasoactive substances and chemicals released by mast cells include: histamine, serotonin, leukotrienes, prostaglandins, tryptase, chymotrypsin, cathepsin G, PAF, eosinophils and hooligans Granulocyte chemokines and the like.
3. Delayed hypersensitivity reaction
Metz et al found significant CD4 T lymphocyte infiltration in the GPC and VKC conjunctiva, and these cells have the characteristics of memory T cells (CD45RO). HLA-DR positive indicates that these cells are activated and the number of macrophages is increased. It is suggested that there is a local antigen presentation process.
4. The role of other cells
In the stromal layer of the conjunctiva of GPC patients, the number of eosinophils increases, alkaline tear protein adheres to the contact lens, and major basic protein of eosinophils can be observed in the conjunctival biopsy specimens of GPC and VKC patients. , MBP) deposition, but MBP was only detected in contact lenses of specific patients.
Many neutrophils can be observed in biopsy specimens of GPC patients. The concentration of neutrophil chemotactic factor (NCF) in GPC tears is 15 times that of normal tears. These NCF may be damaged by Secretion of conjunctival epithelial cells, the appearance of NCF suggests the relationship between trauma and GPC. The NCF concentration of tears in contact lens wearers but not GPC is only three times the normal level. The above phenomenon suggests simple physics. Trauma plays a role in the early stages of GPC pathogenesis, and the conjunctival goblet cells and non-cup-shaped epithelial cells can produce GPC-specific thick filamentous secretions.
5. Immunohistochemistry of the conjunctiva
Immunohistochemical studies of sputum conjunctiva and bulbar conjunctiva from untreated, severely staged GPC patients revealed multiple inflammatory cell infiltrations in diseased tissues, including mast cells, eosinophils, and hooliganism. The increase in the number of neutrophils, macrophages and CD4 T cells suggests that type I and type IV hypersensitivity reactions occur, whereas in the corresponding VKC patients, the infiltrating cell pattern is similar to GPC, but neutrophil infiltration is more common. Heavy, while the number of CD4 T cells is small.
6. Adhesion molecules
Like other forms of allergic conjunctivitis, vascular endothelial cell adhesion molecules may play an important role in the cellular infiltration of tissues during the onset of GPC. Many cytokines (IL-1, IL-4, TNF- and IFN-) ) can induce vascular endothelial cells to express immunoglobulin-like intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin and others, or up-regulate the basal expression of its ICAM-1, which captures circulating leukocytes that carry the corresponding ligand during vascular flow and then assists in extravasation through the cell wall, in patients with GPC, ICAM The expression of -1 and E-selectin is elevated, while only a small number of blood vessels express VCAM-1 in the GPC tarsal tissue.
Immunoglobulin
A GPC model was established in the monkey eye, and IgA, IgM, and IgE in the tears were found to be elevated. Plasma cells, lymphocytes, and mast cells were found in the conjunctival stroma. Studies on normal people showed that tears were worn in hard contact lenses. The level of immunoglobulin is higher than that of soft contact lens. The reason may be related to the decrease of corneal sensitivity in hard contact lens. The changes of tear in GPC patients are not consistent.
8. Balance theory
Non-atopic patients with simple corneal deposits or raised filter bubbles can cause severe focal GPC. The above examples suggest that there is no specific antigen in the contact lens, eye prosthesis or suture, but simple Mechanical damage, a significant sign of mast cell degranulation after mechanical stimulation is the occurrence of wheal reaction, several different mechanisms can be associated with mast cell degranulation, including reverse nerve stimulation, human skin mast cells against P Substance, VIP, somatostatin, morphine and complement anaphylatoxins C3a and C5a stimulation, and membrane IgE cross-linking can occur degranulation, mast cells can produce and store IL-4, IL-4 can induce T helper cells, especially It is a Th2-type cell and, therefore, indirectly leads to the production of cytokines that cause an allergic reaction, including IL-4 and IL-5.
Compared with VKC, GPC has a mild degree of eosinophil infiltration, which may be related to the type of T helper cells and atopic phenotype. Eosinophils need to receive IL-5-producing Th2 type CD4+ T cells. The effect of a certain mutual inhibition between non-atopic individuals, Th1 and Th2 type cells, but in atopic individuals, there is positive feedback of Th2 type cells, resulting in amplification of certain cytokine production patterns, Devitrification of mast cells may be the first step in the same pathway in non-atopic individuals, and long-term mechanical stimulation of contact lenses or ophthalmic prostheses will lead to chronic hypertrophy in non-atopic individuals. Cell degranulation, if mast cells are still in the first step of the inflammatory process, then cell infiltration and its clinical features will be very similar to hay fever allergic conjunctivitis, once T lymphocytes and eosinophils are involved, their characteristics will be similar At VKC.
9. Other theories
In patients with GPC, reverse stimulation of unmyelinated nerve fibers will result in degranulation of mast cells, thus causing a large area of inflammation involvement, which may explain the mechanism of GPC caused by sutures, and sodium cromolyn can block triggering by capsaicin. The radioactive stimulation of primary afferent terminals, substance P can cause degranulation of mouse mast cells, leading to secondary granulocyte infiltration, increased tissue edema and vascular permeability.
Prevention
Giant papillary conjunctivitis prevention
Choose a suitable contact lens, and pay attention to the contact lens and the wearing time of the prosthetic eye, while preventing the effects of allergic factors.
Complication
Giant papillary conjunctivitis complications Conjunctival congestion
Conjunctival congestion.
Symptom
Giant papillary conjunctivitis symptoms common symptoms itching hyperemia
The initial symptoms of GPC are mild, with mild irritation, thin viscous secretions and mild itching. If not treated properly, the condition will gradually worsen, due to viscous secretions and protein covering the lens surface. Vision blur can occur, and the persistent foreign body sensation during wearing the lens forces the patient to reduce the wearing time. When the condition reaches a certain level, the patient will be forced to stop wearing the lens and see the doctor. The itching after removing the lens and the eyelid sticking after waking up Together is also a common complaint of GPC.
GPC progresses slowly, and the early manifestations are mild hyperemia and thickening of the upper conjunctiva. As the disease progresses, the inflammatory cell infiltration increases, the conjunctiva begins to thicken and turbid, and the secretions in the early stage are filamentous. Further aggravation of the disease, white mucous secretions, usually located in the inferior vault, continuous contact with the contact lens or contact with the irritant, will lead to further conjunctival hyperemia and inflammatory reaction, the palpebral conjunctiva will appear nipple and gradually increase, in Under normal physiological conditions, the diameter of the nipple is less than 0.3 mm, the diameter of the nipple of giant papillary conjunctivitis is greater than 0.3 mm, and when the diameter of the nipple is greater than 1.0 mm, it is called a giant nipple.
There is a great variability in the appearance and location of the nipple. A1lansmith divides the upper conjunctiva into three zones: zone 1 is the conjunctiva near the iliac crest; zone 3 is the zone near the iliac crest; In the 2nd zone, the soft contact lens associated with the giant papillary conjunctivitis nipple first appeared in zone 1, then progressed to zone 2 and zone 3, while the hard zone, then progressed to zone 2 and zone 1, due to exposure of the suture, GPC occurs in banded corneal degeneration and glaucoma filtering blebs, which are characterized by large clusters of large papillae in the stimulation zone. These signs suggest that chronic mechanical stimulation is an important predisposing factor for giant papillary conjunctivitis in these cases.
Allansmith divides GPC into four phases based on its clinical performance:
Stage I: There is a small amount of mucous secretion in the morning, and there is itching when the lens is taken out; there are occasional deposits on the surface of the lens; the appearance of the palpebral conjunctiva is normal, and may be accompanied by mild to moderate congestion.
Stage II: mucous secretions and itching are aggravated, the feeling of contact lens is increased; the surface of the lens has deposits; the visual acuity is slightly decreased; symptoms appear often within a few hours after wearing the lens, and the patient's ability to wear glasses is reduced or restricted. Slit lamp examination showed mild congestion of the upper conjunctiva, thickening, nipples with different sizes of nipples, diameter more than 0.3mm, adjacent nipples can be fused, raised due to tissue thickening, after fluorescent staining More clearly.
Stage III: mucus secretions and itching are obviously aggravated, and there are often deposits on the surface of the lens. It is difficult to keep the lens clean; each contact has the feeling of contact lens, and the lens is over-displaced, resulting in blurred vision; The wearing time was significantly reduced; the conjunctiva was obviously congested and thickened, the blood vessels were blurred, the size and number of nipples increased, and the nipple was uplifted. Due to the scar formation under the conjunctiva, the top of the nipple was white and fluorescein was stained.
Stage IV: The patient can't stand wearing the mirror at all. After wearing the mirror, it feels uncomfortable for a short time; the surface of the lens quickly forms sediment and dirt, the lens shifts greatly, and the mucous secretion is quite large. In severe cases, the eyelid sticks in the morning. Together, the upper conjunctiva nipple is further enlarged, the diameter is more than 1mm, the tip of the nipple is flat, and the fluorescein is colored.
The clinical classification of GPC indicates the progression of the lesion, but there are often differences in different individuals. Some patients have only early epithelial conjunctiva changes, but have serious symptoms; while others have no symptoms, but on The palpebral conjunctiva has obvious inflammation and nipple hyperplasia.
Seasonal allergy is a risk factor for patients with soft contact lenses. GPC patients have a higher incidence of contact lens preservation solutions, drugs, fungi, pollen and animal allergies than those without GPC contact lenses.
Examine
Giant papillary conjunctivitis examination
Cytological examination of conjunctival sac secretions revealed eosinophilia associated with allergic factors.
The huge nipple is covered with thickened, irregular conjunctival epithelial cells with many crypts. In many cases, epithelial erosion and corresponding fluorescein staining can be observed. Under electron microscope, epithelial cells can be seen in different sizes and lose normal. In the polygonal morphology, the microvilli on the surface are flat, clustered and branched. The increase in mucus secretion of giant papillary conjunctivitis is not related to the increase in the density of goblet cells on the nipple surface, but is related to the increase in the surface area of the conjunctiva covering the surface of the nipple. In the crypt between the nipples, there are often a large number of mucus-secreting cells that are not goblet cells. The secretory vesicles of these cells are significantly increased. The typical feature of giant papillary conjunctivitis is eosinophils and mast cells in the parenchymal parenchyma. Basophils, lymphocytes and plasma cells are infiltrated, but eosinophils, mast cells and basophils are not common in the conjunctival epithelium.
Diagnosis
Diagnosis and differentiation of giant papillary conjunctivitis
GPC can be clinically diagnosed based on a history of wearing a contact lens or installing an eye prosthesis, combined with clinical signs and signs of a giant papilla.
GPC must be differentiated from VKC. The two diseases are often difficult to distinguish in appearance. However, most of VKC occurs in adolescent children. Most of them disappear at the age of 20, which is a very serious disease. It is not related to wearing contact lenses. GPC generally Wearing contact lenses, without corneal ulcers and corneal opacity, VKC patients with conjunctival scrapings generally have eosinophils, while GPC patients only account for 25%, similarly, VKC patients have eosinophilic particles, while GPC patients In the absence of VKC patients, the histamine level of tears was significantly increased, while in GPC patients there was no significant increase.
Occasionally, bacterial conjunctivitis is similar to GPC symptoms, but the secretion of bacterial conjunctivitis is mostly purulent, white-viscous, a small number of chlamydia, adenovirus and follicular follicles of primary herpetic conjunctivitis and giant papilla of GPC Confusion, can be distinguished by contact lens or other eye prosthesis.
