JP2019201850A - Method for predicting risk of decrease in cornea endothelial cell density - Google Patents

Abstract

To provide a method suitable for predicting the risk of decrease in cornea endothelial cell density.SOLUTION: The method includes the step of inspecting iris damages of a subject and the step of inspecting hydatoid cytokine densities of the subject, and on the basis of the respective results of inspection of the iris damages and the hydatoid cytokine densities, the risk of decrease in cornea endothelial cell density of the subject is predicted.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for use in predicting the risk of a decrease in corneal endothelial cell density.

The cornea is a translucent body that plays the role of a lens in the front center of the eyeball, and has a five-layer structure of corneal epithelium, Bowman's membrane, corneal stroma, Descemet's membrane, and corneal endothelium. Corneal endothelial dysfunction, i.e. bullous keratopathy, caused by corneal endothelial damage is the most common cause of blindness resulting from corneal disease. Bullous keratopathy is usually said to develop when the density of corneal endothelial cells of about 2500 to 3000 cells / mm ² is about 500 cells / mm ² or less. Clinical factors such as dystrophy and internal eye surgery are considered to be involved. However, in all cases with these clinical factors, corneal cell density did not decrease, and it was not clear why corneal endothelial cells decreased or in which patients corneal endothelial cells decreased. That is, the detailed cause of the decrease in the corneal endothelial cell density is unknown, and the risk of the decrease in the corneal endothelial cell density is difficult to predict. Since corneal endothelial cells do not divide and the number of them is decreasing, clinically, we consider cases with low corneal endothelial cell density during intraocular treatment such as surgery to be cautionary, and conservatively progress after surgery Even if there were cases in which the cell density in the cornea significantly decreased during the observation process, there was no choice but to continue the follow-up, and its treatment and prevention were difficult.

  On the other hand, research on a decrease in the density of corneal endothelial cells has also been conducted extensively. According to the inventors, there is a case in which the cytokine composition of the anterior chamber water changes at a stage where corneal endothelial cell density has decreased but has not yet led to bullous keratopathy, and when bullous keratopathy has developed The kind of the anterior chamber fluid cytokine which rises is specified (nonpatent literature 1). It has also been clarified that in cases where the severity of iris damage is high, the decrease in corneal endothelial cell density after corneal transplantation is accelerated, in other words, the rate of decrease is increased (Non-patent Document 2). It has also been clarified that the decrease rate of the corneal endothelial cell density is significantly increased in cases where the specific cytokine concentration in the anterior aqueous humor is high before surgery (Non-patent Document 3). There may be a correlation between iris damage and anterior aqueous humor cytokine concentration, such as higher anterior chamber cytokine levels in cases with iris damage compared to cases without iris damage. It has been reported (Non-Patent Document 4).

Takefumi Yamaguchi, et. Al., “Elevated Cytokine Levels in the Aqueous Humor of Eyes With Bullous Keratopathy and Low Endothelial Cell Density”, Investigative Ophthalmology & Visual Science, The Association for Research in Vision and Ophthalmology, November 2016, Vol. 57, No. 14, P5954-5962 Nobuhito Ishii, et al., “Factors associated with graft survival and endothelial cell density after Descemet ’s stripping automated endothelial keratoplasty”, Scientific Reports, Macmillan Publishers Limited, 28 April 2016, 6: 25276, DOI: 10.1038 / srep25276, P1-10 Yukari Yagi-Yaguchi, “Preoperative Aqueous Cytokine Levels Are Associated With a Rapid Reduction in Endothelial Cells After Penetrating Keratoplasty”, American Journal of Ophthalmol, Elsevier Inc., 2017, Vol. 181, P166-173 Naohiko Aketa, et. Al., “Iris Dammage Is Associated With Elevated Cytokine Levels in Aqueous Humor”, Investigative Ophthalmology & Visual Science, The Association for Research in Vision and Ophthalmology, 2017, Vol. 58, No. 6, BIO42-51

  As described above, in conventional clinical practice, it has been considered difficult to predict the risk of corneal endothelial cell density reduction and take necessary measures. However, recent research suggests that there is a direct strong link between, for example, decreased corneal endothelial cell density and the pathologic environment of the anterior aqueous humor, such as corneal endothelial cell density. The results that can be expected to be applied to the prediction of the risk of decrease are being obtained. If the risk of decrease in corneal endothelial cell density can be predicted, it is possible to provide information on the predicted postoperative value in advance for corneal transplant surgery patients or endoscopic surgery patients such as cataracts and glaucoma. Various contributions can be expected, such as prevention of the decrease in the amount of cancer, or early application of treatment.

  Therefore, an object of the present invention is to provide a method suitable for predicting the risk of decrease in corneal endothelial cell density.

  The method according to one aspect of the present invention includes a first examination procedure for examining the degree of iris damage of a subject, and a second examination procedure for examining the anterior chamber fluid cytokine concentration of the subject. And the risk of a decrease in the corneal endothelial cell density of the subject based on the respective test results of the anterior aqueous humor cytokine concentration.

  Predicted that the degree of iris damage is related to the state of the anterior aqueous humor environment, and in cases with high severity of iris damage, the anterior aqueous humor cytokine concentration is high and therefore the risk of reducing corneal endothelial cell density is also high Can hold. However, the level of iris damage alone is not always sufficient to predict the risk of corneal endothelial cell density reduction. Therefore, the anterior aqueous humor cytokine concentration is examined together, and in addition to the degree of iris damage, the measured value of the anterior aqueous humor cytokine concentration is used as an index for predicting the corneal endothelial cell density. Thereby, it is possible to reliably predict the risk of decrease in corneal endothelial cell density without relying on test results of a single index. That is, while using the degree of iris damage as a guideline for predicting the risk of corneal endothelial cell density reduction, the measured value of the anterior chamber cytokine concentration is further used as an index for quantitative prediction of the risk of corneal endothelial cell density reduction. Thereby, a reliable prediction can be made regarding the risk of corneal endothelial cell density reduction.

  In the above aspect, in the first inspection procedure, it is determined whether or not the degree of iris damage of the subject exceeds a predetermined level, the second inspection procedure is performed on the subject exceeding the predetermined level, The reduction risk may be predicted based on the inspection result of the second inspection procedure. A subject whose iris damage degree is higher than a predetermined level is predicted to have a considerably high risk of corneal endothelial cell density reduction. For such subjects, the risk of a decrease in corneal endothelial cell density can be reliably predicted by conducting an examination of the anterior aqueous humor cytokine concentration and using the obtained numerical values for prediction. On the other hand, for subjects who have a relatively low risk of increasing the aqueous humor cytokine concentration, the burden on the subject can be reduced by omitting the procedure after the examination of the anterior aqueous humor cytokine concentration.

  In the above aspect, in the first inspection procedure, the degree of iris damage may be inspected based on the iris image of the subject imaged using far infrared light. According to this, even if the eye has a disease such as a corneal cloudy eye, the degree of iris damage can be accurately inspected using an image using far-infrared light.

  In the above aspect, in the second examination procedure, the anterior chamber fluid cytokine concentration may be examined using tears collected from the subject. There is a correlation between the cytokine concentration in the tear fluid and the anterior chamber fluid cytokine concentration, and if the cytokine concentration in the tear fluid is examined, the anterior chamber fluid cytokine concentration can be indirectly examined. Tear fluid is present on the surface of the eye and can be collected from the subject with less invasiveness than the anterior aqueous humor. Therefore, compared with the case where the anterior aqueous humor is collected and the cytokine concentration is directly examined, the burden on the subject can be reduced.

FIG. 9 shows a procedure of a method according to one embodiment of the present invention. The image which shows the example applicable to each of the grades 0-4 of the degree of iris damage. The figure which shows the procedure of the method which concerns on the other form of this invention. Correlation coefficient between the measured value of tear cytokine concentration and the measured value of anterior aqueous humor cytokine concentration in a measurement test conducted to confirm the correlation between tear cytokine concentration and anterior aqueous humor cytokine concentration The figure which shows the result of having calculated | required p value and 95% confidence interval. The figure which shows the relationship between the density | concentration of the anterior aqueous humor MCP-1 and the density | concentration of tears IL-4 of each sample in a measurement test. The figure which shows the relationship between the density | concentration of the anterior aqueous humor MCP-1 of each sample in a measurement test, and the density | concentration of tears IL-1 (alpha).

  An example of the procedure of the prediction method according to one embodiment of the present invention is shown in FIG. The illustrated method includes a procedure for examining the degree of iris damage (first examination procedure), a procedure for examining the anterior chamber cytokine concentration (second examination procedure), and corneal endothelial cell density based on the examination results. And a procedure for predicting the reduction risk (prediction procedure). Hereinafter, specific contents of each procedure will be described in order.

(Iris damage test)
The examination of the degree of iris damage is performed by, for example, irradiating far-infrared light to the anterior eye portion of the subject and photographing an iris image based on the reflected light. As an example of an inspection device for acquiring such an image, an anterior ocular segment optical interferometer can be used. By acquiring an image of the iris by far-infrared light, for example, even an eye with a disease such as a corneal cloudy eye, an image reflecting the state of the iris should be acquired and used to determine the degree of iris damage Is possible. However, the inspection of the degree of iris damage may be performed using another inspection device such as a slit lamp inspection device.

  The examination result of the degree of iris damage can be shown by classifying the iris image according to the severity of the degree of iris damage. As an example, the severity is evaluated by dividing into 5 grades of grades 0 to 4. Grade 0 is a normal case with no iris damage, Grade 1 is a case with damage only in one quadrant of the iris, Grade 2 is a case with damage only in the two quadrants of the iris, Grade 3 is A case in which damage has occurred over the three quadrants of the iris, grade 4 is a case in which damage has occurred over the entire surface of the iris. By analyzing the photographed iris image, it is possible to determine which of the grades 0 to 4 corresponds to the degree of damage to the subject's iris. In addition, the example of each image of grade 0-4 is shown in FIG. Whether the iris image of the subject corresponds to grade 0 to 4 may be determined by visual inspection by the examiner, or may be determined using an image processing method. For example, the iris damage reference image is prepared in advance, the iris image is divided into four quadrants, and the iris damage degree is determined by a method such as whether or not there is an image having a matching level with the reference image or more in each quadrant. It is also possible to make a uniform determination.

  After determining the grade of the degree of iris damage, the risk of decreasing the corneal cell density of the subject may be further predicted based on the test results. For example, the correlation between the degree 0 to 4 of the degree of iris damage and the decrease risk of the corneal endothelial cell density is investigated in advance, an evaluation standard is set in advance based on the result of the investigation, and the grade as the result of the examination of the degree of iris damage And the evaluation criteria may be compared to predict the level of decrease in the corneal endothelial cell density of the subject. For example, if the degree of iris damage is grade 3 or higher, the risk of a decrease in corneal endothelial cell density may be predicted to be correspondingly high. However, there are cases in which the cytokine concentration is relatively high even if the degree of iris damage is mild. For example, in a case where there is a history of argon laser iridotomy or capsular glaucoma and the corneal endothelial cell density has already decreased, the cytokine concentration may be relatively high even if the degree of iris damage is mild. Considering the existence of such exceptional cases, it is not always appropriate to uniformly predict that the risk of reduction in corneal endothelial cell density is low due to the mild degree of iris damage. Therefore, even when the evaluation standard is set as the risk of reduction is high when the degree of iris damage is grade 3 or higher, if the evaluation standard is set to grade 2 or lower, it is not determined definitively as the risk of reduction is low, and this is an exceptional case You may make it add further examination, such as whether or not.

  The iris damage in the above procedure is a concept including iris depigmentation, iris defect, and iris parenchymal damage. Since the iris pigment epithelial cells are cells existing on the surface of the iris, any of the above diseases can be regarded as a state in which the iris pigment epithelial cells are damaged. Therefore, iris damage is a concept that should be broadly interpreted as meaning that the state of the iris pigment epithelial cells is not in a normal state.

(Examination of anterior aqueous humor cytokine concentration)
In the examination of the anterior chamber fluid cytokine concentration, the cytokine concentration in the anterior chamber water in the subject is measured by using a known measurement method such as a multiplex bead assay method or an enzyme-linked immunosorbent assay (ELISA). Is implemented. The multiplex bead assay is highly sensitive and accurate, and can measure the concentration of a plurality of substances (for example, about 50) simultaneously, and the amount of anterior aqueous humor that can be collected is small. Suitable for concentration inspection. Examples of cytokines serving as an index for concentration measurement include IL-6, IL-1, IL-12, TNFα, MCP-1, IFNγ, and sICAM-1.

  The sample used for the examination of the anterior aqueous humor cytokine concentration may be an anterior aqueous humor collected from the subject, but tears can also be used. In cases of developing specific corneal diseases, there is a strong correlation between the cytokine concentration in tears and the cytokine concentration in anterior aqueous humor. Moreover, tears are present on the surface of the eye and can be collected from the subject with less invasiveness than the anterior aqueous humor. Therefore, if the cytokine concentration is measured using the subject's tears, the anterior chamber fluid cytokine concentration can be indirectly examined.

(Prediction of risk of decrease in corneal endothelial cell density)
The risk of decreasing the corneal endothelial cell density is predicted based on the above-described test results of the degree of iris damage and the concentration of anterior chamber fluid. If the degree of iris damage exceeds a predetermined level and the anterior aqueous humor cytokine concentration is higher than a predetermined level, the risk of a decrease in corneal endothelial cell density is considerably high, for example, for future bullous keratopathy It can be determined that the onset is predicted with high probability. As a procedure for carrying out such a prediction, an evaluation criterion for associating each test result of the degree of iris damage and anterior aqueous humor cytokine concentration with the risk of decreasing the corneal endothelial cell density is set in advance, and the test in each of the above test procedures An example is a procedure for comparing a result with an evaluation standard and predicting a decrease risk of corneal endothelial cell density in a subject. For example, when the degree of iris damage is grade 3 or higher in FIG. 2 or when the degree of cytokine damage is higher than a predetermined level even if the degree of iris damage is less than grade 3, the risk of corneal endothelial cell density decreasing after corneal transplantation Can be predicted to be high. In this case, as an example of the cytokine concentration, 100 pg / ml for IL-alpha, 10 pg / ml for IL-β, 500 pg / ml for IL-6, 10 pg / ml for IL-10, IL-12p70 and IL-17A, Using MCP-1 at 700 pg / ml, TNFα at 150 pg / ml, and INFγ at 80 pg / ml, it can be determined that the concentration is higher than a predetermined level when the concentration is higher than those values. However, the standard of these concentrations may change as appropriate depending on the measurement method and the like, and may be set as appropriate according to the clinical setting. Furthermore, the reduction risk prediction may be performed, for example, by classifying the reduction risk into a plurality of stages and determining which classification the test result of the subject belongs to. The classification used for evaluation criteria and determination can be set by performing the above-described tests on a large number of cases and calculating the correlation between the test results and the decrease rate of the corneal endothelial cell density in each case.

  For subjects with low severity of iris damage, it can be estimated that, except for the exceptional cases described above, the anterior chamber cytokine concentration is low and the risk of corneal endothelial cell density reduction is correspondingly low. . As shown in FIG. 1, when the iris damage degree test and the anterior aqueous humor cytokine concentration test are performed in a permutation, it is judged that the iris damage degree test result is good, that is, the degree of damage is below a predetermined level. For those who are to be tested, the test of the anterior chamber fluid cytokine concentration may be omitted, leading to a prediction that the risk of reduction is low. In other words, the anterior aqueous humor cytokine concentration test is performed only in cases where the degree of iris damage of the subject exceeds a predetermined level, and the obtained anterior aqueous humor cytokine concentration is compared with a predetermined evaluation standard to determine the corneal endothelial cell density. The risk of reduction may be predicted. In this case, the examination of the degree of iris damage is positioned as a procedure for selecting a case where the examination of the anterior aqueous humor cytokine concentration should be performed. However, as described above, some cytokine concentrations do not necessarily depend on the degree of iris damage, and even if the degree of iris damage is low, the cytokine concentration may be high. Therefore, when selecting a case where a cytokine concentration test should be performed based on the result of the test of the degree of iris damage, for example, a case of an iris damage degree of grade 3 or higher, or a hereditary cornea such as Fuchs corneal endothelial dystrophy Do not rely on the level of iris damage, such as applying a cytokine concentration test, in cases where the eye is a corneal endothelial cell-depleted eye that has a cause other than internal disease and is associated with iris damage, etc. Considering these clinical factors, selection criteria for cases to be examined for cytokine concentration may be appropriately set.

  However, the method of the present invention is not limited to the form of FIG. For example, as shown in FIG. 3, the examination of the degree of iris damage and the examination of the anterior aqueous humor cytokine concentration are performed in parallel, and the risk of corneal endothelial cell density reduction is predicted by combining the examination results. Good. In this case, since the degree of iris damage and the anterior chamber fluid cytokine concentration are examined for all cases, the risk of corneal endothelial cell density reduction can be predicted by combining the respective examination results. For example, it is possible to predict the risk of corneal endothelial cell density reduction in multiple stages according to the combination of grades 0 to 4 as the result of iris damage test and the numerical range of anterior chamber fluid cytokine concentration. is there. Regardless of whether the procedure of FIG. 1 or FIG. 3 is used, when the examination of the degree of iris damage and the examination of the concentration of anterior aqueous humor are performed on all cases, the cytokine is in spite of the low degree of iris damage. It is possible to reliably extract a case having a high concentration and improve the accuracy of predicting the risk of a decrease in corneal endothelial cell density.

  Next, a specific example in which the above method is applied to an actual case will be described. As a result of the examination of the degree of iris damage on 340 cases, 98 grade 0, 85 grade 1, 78 grade 2, 45 grade 3, 28 grade 4, 28 measurement inability There were 8 people. Unmeasurable cases are due to extremely strong corneal opacity. In addition, for the same 340 cases, the anterior chamber fluid cytokine concentration before the operation was examined, and the correlation between the test result and the decrease rate of the corneal endothelial cell density after the operation was investigated. As a result, the rate of decrease in corneal endothelial cell density is extremely small in cases where the anterior chamber fluid cytokine concentration shows a normal value, and the rate of decrease in corneal endothelial cell density is the case in cases where the anterior chamber fluid cytokine concentration is moderately increased. There was a big trend. Acute dysfunction of corneal grafts was observed in cases where the anterior aqueous humor cytokine concentration was as high as 1000 times the normal value. Further, among the cases to which corneal endothelium transplantation was applied, the relationship between the grade of iris damage degree and anterior aqueous humor cytokine concentration was confirmed for some of the cases judged to be grades 1-4 (67 eyes) The results showed that the anterior aqueous humor cytokine concentration was very high in 9% for grade 1, 45% for grade 2, 40% for grade 3, and 70% for grade 4. In cases with very high anterior aqueous humor cytokine levels, a sharp decrease in corneal endothelial cells was observed after corneal endothelial transplantation. A comparison between Grade 1 and Grade 4 cases shows a clear link between the degree of iris damage and the risk of decreased corneal endothelial cell density, but is not necessarily linear in the intermediate stages of Grades 2 and 3. Correlation may not exist. Therefore, it is important to predict the risk of corneal endothelial cell decrease by combining the classification of the severity of iris damage and the measurement of anterior aqueous humor cytokine concentration.

  Moreover, the result of the measurement test implemented in order to confirm the correlation with tear cytokine concentration and anterior aqueous humor cytokine concentration is shown in FIGS. The test was conducted on 37 eyes (14 men, 33 women) who developed bullous keratosis, and the tears and anterior aqueous humor in each case were collected as samples and included in the obtained samples. The cytokine concentration was measured, and the correlation between the two concentrations was evaluated by a method of evaluating by the correlation coefficient r, p value and 95% confidence interval (95% CI). As cytokines to be measured, IL-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-17A, MIP-1α, MIP-1β 19 types of cytokines, MCP-1, TNF-α, IFN-α, IFN-γ, E-Selectin, P-Selectin, sICAM-1, and IP10 were selected.

  FIG. 4 shows the correlation coefficient r regarding the relationship between the measured values of 19 cytokine concentrations in the anterior aqueous humor and the measured values of three cytokine concentrations of IL-1α, IL-1β, and IL-4 in tear fluid. , P value (P value) and 95% confidence interval (95% CI) are shown in tabular form. As shown in bold letters in the table, it was confirmed that there was a strong correlation between some tear cytokines selected as measurement targets and anterior aqueous humor cytokines. That is, IL-1α in tear fluid has a strong correlation with IL-1α, MIP-1α, MCP-1, E-Selectin, and P-Selectin in anterior chamber water, and IL-1β in tear fluid is an anterior chamber. There is a strong correlation with IL-17A in water, and IL-4 in tears is strongly correlated with IL-1α, IL-10, MIP-1α, MCP-1, E-Selectin and S-selectin in anterior aqueous humor It was confirmed that it has sex. FIG. 5 shows the results of plotting the measurement results of the sample with the concentration of the anterior aqueous humor MCP-1 on the horizontal axis and the concentration of tear IL-4 on the ordinate, and FIG. The result of plotting the measurement results of the sample with the concentration of 1 on the horizontal axis and the concentration of tear IL-1α on the vertical axis is shown. As is clear from these results, there is a strong correlation between the cytokine concentration in tear fluid and the cytokine concentration in anterior aqueous humor depending on the type of cytokine. Therefore, the tear cytokine concentration can be measured, and the anterior chamber cytokine concentration can be estimated from the measurement results, or the anterior chamber cytokine concentration can be replaced with the tear cytokine concentration to predict the risk of corneal endothelial cell density reduction It was confirmed.

  As described above, according to the method of the present invention, by using the test result of the degree of iris damage and the test result of the anterior chamber fluid cytokine concentration in combination, it is possible to predict with high reliability regarding the risk of decreasing the corneal endothelial cell density. Can be done. If the risk of decreasing the corneal endothelial cell density can be predicted, a path to preventive treatment according to the risk can be opened. For example, it is possible to suppress a decrease in corneal endothelial cell density by applying a preventive treatment such as administration of an inhibitor of a corneal endothelial cell reducing factor, or transplantation or injection of iris epithelial cells. In addition, for cases where surgery such as corneal transplantation should be applied, the risk of corneal endothelial cell density reduction is predicted at the pre-operative stage, and prophylactic treatment is performed for high-risk cases, and the postoperative course Improvements can be made, or useful information regarding the presence or absence of postoperative risks can be provided to the patient at the preoperative stage. It is also possible to provide information that the risk of a decrease in corneal endothelial cell density is low in the future in cases where the risk of the decrease in corneal endothelial cell density is low.

Claims (4)

  A first examination procedure for examining the degree of iris damage of the subject and a second examination procedure for examining the anterior chamber fluid cytokine concentration of the subject, each examination of the degree of iris damage and the anterior chamber fluid cytokine concentration A method for predicting a risk of a decrease in corneal endothelial cell density of the subject based on a result.   In the first inspection procedure, it is determined whether or not the degree of iris damage of the subject exceeds a predetermined level, the second inspection procedure is performed on the subject exceeding the predetermined level, and the second inspection is performed. The method of claim 1, wherein the risk of reduction is predicted based on test results of a procedure.   The method according to any one of claims 1 and 2, wherein in the first inspection procedure, the degree of iris damage is inspected based on an iris image of a subject photographed using far-infrared light.   The method according to any one of claims 1 to 3, wherein in the second examination procedure, the anterior chamber fluid cytokine concentration is examined using tears collected from a subject.