Method for predicting functional outcome of rhegmatogenous retinal detachment involving macular area

Abstract

FIELD: ophthalmology; ophthalmic surgery.SUBSTANCE: intended to predict the functional outcome of surgical treatment of rhegmatogenous retinal detachment involving the macular zone. Before surgery, optical coherence tomography of the macular area of the retina is performed. The length of the retinal photoreceptors in the central B-scan, the degree of damage to the ellipsoid zone, the duration of retinal detachment and the location of the retinal break are determined. Based on the complex of obtained indicators, the predicted maximum corrected visual acuity (MCVA) is calculated 6 months after surgical treatment using the developed mathematical formula. If the MCVA value is more than 0.6, a favorable functional outcome of surgical treatment is predicted.EFFECT: objective personalized prognosis of maximum visual acuity in the postoperative period, which allows for the optimization of patient management tactics through a comprehensive assessment of the structural parameters of the retina and the patient's clinical data.1 cl, 3 ex

Description

[0001] The invention relates to the field of medicine, namely to ophthalmology, and is intended to predict the functional outcome of rhegmatogenous retinal detachment involving the macular zone.

[0002] Rhegmatogenous retinal detachment (RRD) is one of the most severe ocular diseases, leading to a significant decline in visual function. Despite the high effectiveness of modern surgical treatments in achieving anatomical success, functional outcomes in the postoperative period remain variable and difficult to predict, indicating the need for objective criteria for assessing the functional potential of the retina.

[0003] A known method for predicting the functional state of the retina after surgery for its detachment, including the preoperative determination of the amplitude-temporal parameters of the electroretinogram and the threshold of retinal electrical sensitivity based on the phosphene phenomenon in both eyes. Moreover, if the amplitude-temporal parameters change by no more than 28% compared to the fellow healthy eye and the threshold of electrical sensitivity is up to 180 μA, the functional preservation of the retina is predicted [patent RU 2050827, 1992]. In this method, the assessment of the functional outcome is based on a comparative analysis of the electrophysiological parameters of the affected and fellow eyes, which allows us to draw a conclusion about the potential preservation of the retina after surgical treatment. At the same time, the known method does not provide for a quantitative prediction of postoperative visual acuity and allows us to evaluate the general trend of the functional outcome.Furthermore, this method relies on specialized electrophysiological studies that require additional equipment, making it difficult to use in routine clinical practice. It also does not take into account the morphological state of the macular region, specifically the outer layers of the retina and photoreceptors. Furthermore, this method is used postoperatively to assess visual function.

[0004] A known method for determining postoperative visual acuity (VA) in patients with primary RRD, includes determining preoperative visual acuity, duration and height of retinal detachment in the macular zone (MA), retinal detachment area, recording the b-wave of a general electroretinogram, measuring intraocular pressure and subsequent calculation of the predicted postoperative visual acuity using a mathematical formula [patent RU 2270596, 2006]. In this method, predicting the functional outcome is based on an analysis of a set of clinical, electrophysiological and morphological parameters expressed in arbitrary units, while the weighting coefficients of the factors are determined on the basis of the Spearman rank correlation coefficient based on the results of examining a large sample of patients. However, the known method has a number of limitations.In particular, it does not take into account the condition of the outer retinal layers and photoreceptors of the retinal mucosa, which, according to current understanding, play a key role in determining the functional outcome after surgical treatment of rhegmatogenous retinal detachment. Furthermore, the method is based on electrophysiological studies and parameters expressed in arbitrary units, which complicates its practical application and limits the reproducibility of results in routine clinical practice. The method is also used postoperatively to determine visual function.

[0005] The closest analogue (prototype) of the claimed invention is a method for predicting postoperative visual acuity in endovitreal surgery for rhegmatogenous retinal detachment [patent RU 2654585 C1, 2018], including measuring the length of the anteroposterior axis of the eye, determining the best-corrected visual acuity, the duration of retinal detachment and the duration of surgical manipulations in the vitreous cavity intraoperatively, followed by calculating the predicted value of postoperative best-corrected visual acuity according to a linear regression formula using the specified parameters. In the known method, the predicted value of postoperative best-corrected visual acuity is calculated based on clinical and intraoperative indicators. This method allows for a quantitative assessment of the expected postoperative VA 6 months after surgical treatment of rhegmatogenous retinal detachment.

[0006] However, the disadvantage of this method is the lack of assessment of the morphological state of the macular zone of the retina, in particular, the outer layers of the retina and photoreceptors, and the use of the duration of surgical manipulations in the vitreous cavity as a prognostic parameter limits the possibility of using the method at the stage of preoperative planning and reduces its clinical versatility, focusing mainly on clinical and intraoperative indicators, which reduces the accuracy of predicting the functional outcome in patients with pronounced morphological changes in the outer layers of the retina with comparable clinical data.

[0007] The objective of the present invention is to develop a method for preoperative prediction of the functional outcome of retinal detachment.

[0008] The technical result of the invention is the possibility of preoperative planning of the most adequate tactics of surgical intervention in case of rhegmatogenous retinal detachment.

[0009] The technical result is achieved through a set of quantitative and qualitative morphological characteristics of the macular zone based on optical coherence tomography data with the receipt and evaluation of a quantitative indicator of the visual acuity, calculated using a specific formula 6 months after surgical treatment.

[0010] Increasing the reliability and reproducibility of predicting the BCVA 6 months after surgical treatment of RRD by taking into account the condition of the outer layers of the retina (length of photoreceptors, condition of the ellipsoid zone), using objective digital values ​​of OCT biomarkers in the regression formula, obtaining a model that explains a significant proportion of the variability in postoperative BCVA in the analyzed clinical sample ensures the clinical accuracy of the forecast necessary for choosing surgical treatment tactics.

[0011] The method is carried out as follows

[0012] Prior to surgery, optical coherence tomography of the macular area of ​​the retina is performed. The length of the retinal photoreceptors in the central B-scan, the degree of ellipsoid zone impairment, the duration of retinal detachment, and the location of the retinal break are determined. The predicted best-corrected visual acuity (BCVA) 6 months after surgery is calculated using the formula: Y = K + b1 × X1 + b2 × X2 + b3 × X3 + b4 × X4,

[0013] K - constant=0.466; b1-b4 - regression coefficient values: b1=0.0033, b2=-0.103, b3=-0.0020, b4=-0.064, X1-X4 - values ​​of the patient's parameters under study: X1 - preoperative photoreceptor length (μm), X2 - ellipsoid zone (EZ) integrity in points: 0 - EZ intact, 1 - EZ continuous with hyporeflective areas, 2 - EZ discontinuous, 3 - EZ absent, X3 - duration of rhegmatogenous retinal detachment (days), X4 - retinal break localization: 0 - upper, 1 - lower. If the PMCO value is more than 0.6, a favorable functional outcome of surgical treatment of rhegmatogenous retinal detachment involving the macular zone is predicted.

[0014] OCT scanning of the macular zone is performed on any clinically certified device that provides sufficient resolution to visualize the outer layers of the retina, preferably in the cross-line mode for measurement at the fovea. The length of the photoreceptors is measured as the distance in micrometers from the inner border of the external limiting membrane (ELM) to the outer end of the photoreceptors in the central B-scan. The condition of the ellipsoid zone (ELZ) is assessed using a point scale: 0 - ELZ is intact; 1 - ELZ is continuous with hyporeflective areas; 2 - discontinuous ELZ; 3 - absent ELZ. The duration of retinal detachment is defined as the number of days since the decrease in vision. The localization of the break according to ophthalmoscopy data is determined in points as superior - 0, inferior - 1.

[0015] This formula was derived from statistical analysis of clinical data from patients with primary RRD involving the macular area. Prognostically significant parameters influencing BCVA were selected using correlation analysis, which yielded parameters demonstrating a statistically significant relationship with the functional outcome of treatment. To validate the resulting predictive model, it was verified on a sample of 271 patients undergoing surgery for RRD, with functional outcome assessed 6 months after surgery. The maximum deviation of the predicted BCVA from the actual value was 0.2, with a mean deviation of 0.06, which is considered clinically insignificant.

[0016] The regression coefficients of the indicators selected to predict the final postoperative BCVA and the constant value calculated by the multiple linear regression method are presented below:

[0017]

[0018] The proposed method is illustrated by the following clinical examples:

[0019] 1. Patient K., 54 years old, diagnosed with primary RRD involving the retinal zone and a superior retinal break. Retinal detachment lasted 18 days. Preoperative OCT of the retinal zone revealed the following parameters: photoreceptor length - 82 µm, ellipsoid zone impairment grade - 0 (preserved).

[0020] In the preoperative period, the predicted BCVA 6 months after surgery was calculated using the formula:

[0021]

[0022] The BCVA was 0.71, which corresponds to a favorable functional outcome and allows for objective information about the patient's current functional status. Given the high potential for visual recovery, the patient was recommended for urgent surgical intervention. Six months after surgery, the actual BCVA was 0.7. The deviation of the predicted value from the actual value was 0.01, demonstrating high prognostic accuracy.

[0023] 2. Patient M., 63 years old, diagnosed with primary RRD involving the retinal mucosa, inferior retinal break. Retinal detachment duration: 26 days. Preoperative OCT of the retinal mucosa revealed the following parameters: photoreceptor length - 68 µm, ellipsoid zone defect degree - 2 (discontinuous).

[0024] Predicted BCVA at 6 months:

[0025] MCOS 6мес =0.466+0.0033⋅68-0.103⋅2-0.0020⋅26-0.064⋅1=0.37

[0026] The BCVA is 0.37, which corresponds to a moderate functional prognosis and indicates limited potential for central vision recovery after vitreoretinal surgery. The actual BCVA 6 months after surgery was 0.4. The deviation of the predicted value from the actual value was 0.03, indicating sufficient prognostic accuracy. Despite the limited recovery of visual function according to the BCVA, the risk of loss of functional response determines the need for urgent surgery.

[0027] 3. Patient S, 71 years old, diagnosed with primary retinal detachment involving the macular region, superior retinal break. Retinal detachment duration: 38 days. Preoperative optical coherence tomography of the macular region revealed the following parameters: photoreceptor length - 45 μm, ellipsoid zone impairment degree - 2 (discontinuous).

[0028]

[0029] The BCVA is 0.22, which corresponds to an unfavorable functional prognosis and indicates a low expected level of central vision recovery after vitreoretinal surgery, which allowed for objective patient information. Surgical treatment is indicated on a planned basis due to the low expected level of functional recovery of central vision. The actual BCVA 6 months after surgery was 0.2. The deviation of the predicted value from the actual value is 0.02, which is clinically insignificant and indicates sufficient prognostic accuracy.

[0030] Thus, the proposed method allows predicting the functional outcome of surgical treatment of rhegmatogenous retinal detachment with sufficient clinical accuracy and can be used for preoperative planning and informing patients about the possible outcome of surgical intervention.

Claims

A method for predicting the functional outcome of surgical treatment of rhegmatogenous retinal detachment involving the macular zone, characterized in that prior to surgery, optical coherence tomography of the macular zone of the retina is performed, the length of the retinal photoreceptors in the central B-scan, the degree of damage to the ellipsoid zone, the duration of retinal detachment and the localization of the retinal break are determined, and the predicted best-corrected visual acuity (BCVA) is calculated 6 months after surgical treatment using the formula: Y=K+b1×X1+b2×Х2+b3×Х3+b4×Х4, K is a constant = 0.466; b1-b4 are the regression coefficient values: b1 = 0.0033, b2 = -0.103, b3 = -0.0020, b4 = -0.064, X1-X4 are the values ​​of the patient's parameters under study: X1 is the preoperative length of photoreceptors, µm, X2 is the integrity of the ellipsoid zone (EZ) in points: 0 - EZ is intact, 1 - EZ is continuous with hyporeflective areas, 2 - EZ is intermittent, 3 - EZ is absent, X3 is the duration of rhegmatogenous retinal detachment, days, X4 is the localization of the retinal break: 0 - superior, 1 - inferior, and if the PMVA value is more than 0.6, a favorable functional outcome of surgical treatment of rhegmatogenous retinal detachment with involvement of the macular zone is predicted.

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