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Electroretinography (ERG) is a diagnostic procedure utilized to assess and evaluate the functionality of the retina and optic nerve by measuring the electrical responses generated by retinal cells when exposed to light stimuli. This test is particularly important for diagnosing various retinal conditions and understanding the overall health of the retina. Prior to the procedure, mydriatic drops are administered to dilate the pupil, which enhances the visibility of the retina during testing. Depending on the specific protocol being followed, the patient may undergo a period of dark or light adaptation lasting several minutes to prepare the retina for accurate measurement. During the procedure, electrodes are carefully placed on the surface of the eye under dim red light to minimize any interference with the test results. Various types of electrodes can be employed, including contact lens electrodes that rest directly on the cornea or gold Mylar tape electrodes positioned between the lower eyelid and the sclera or cornea. These electrodes are then connected to a recording device that captures the electrical activity of the retina. To ensure stability during the test, the patient's head is supported using head and chin rests. The retina is stimulated by a series of light flashes emitted from a bright light source, which may include LEDs, a strobe lamp, or a full-field dome equipped with its own illumination. The electrical responses elicited by these light flashes are recorded first in a dark environment and subsequently with background lighting. The resulting electrical activity is captured by the electrodes and represented digitally as a waveform. In the case of conventional full field or flash ERG, specifically identified by CPT® code 92273, the test evokes a summation of the electrical responses from the entire retina using a Ganzfeld stimulus, which scatters light throughout the eye. While this method effectively records the overall retinal response, it does not provide localized responses. In contrast, multifocal ERG (mfERG) stimulates multiple areas of the retina simultaneously, allowing for the recording of electrical responses from different retinal regions at the same time. After the completion of the ERG test, two primary components are typically analyzed: the a-wave, which reflects the health of the photoreceptors in the outer retina, and the b-wave, which indicates the health of the inner layers of the retina. A comprehensive written interpretation of the findings is subsequently provided to assist in clinical decision-making.
© Copyright 2025 Coding Ahead. All rights reserved.
The electroretinography (ERG) procedure is indicated for the evaluation and diagnosis of various conditions affecting the retina and optic nerve. The following are specific indications for performing this test:
The electroretinography (ERG) procedure involves several critical steps to ensure accurate measurement of the retina's electrical responses. The first step is the administration of mydriatic drops to dilate the pupil, which is essential for optimal visualization of the retina during the test. Following this, the patient undergoes a period of adaptation, either in darkness or light, lasting several minutes, depending on the specific protocol being utilized. This adaptation phase is crucial as it prepares the retinal cells for the subsequent light stimulation.
After the completion of the electroretinography test, the recorded data is analyzed to evaluate the health and functionality of the retina. Two primary components of the electrical response are typically assessed: the a-wave, which corresponds to the health of the photoreceptors in the outer retina, and the b-wave, which indicates the health of the inner layers of the retina. A comprehensive written interpretation of the findings is then provided to the referring physician, which aids in clinical decision-making and further management of the patient's condition. Patients may experience temporary visual disturbances due to the mydriatic drops used during the procedure, and it is generally advised that they have someone accompany them home, especially if they have undergone pupil dilation.
| Short Descr | FULL FIELD ERG W/I&R | Medium Descr | FULL FIELD ELECTRORETINOGRAPHY W/I&R | Long Descr | Electroretinography (ERG), with interpretation and report; full field (ie, ffERG, flash ERG, Ganzfeld ERG) | Status Code | Active Code | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 1 - Diagnostic Tests for Radiology Services | Multiple Procedures (51) | 7 - Special payment adjustment rules on the technical component (TC) of multiple diagnostic ophthalmology services apply... | Bilateral Surgery (50) | 2 - 150% payment adjustment does NOT apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 0 - Payment restriction for assistants at surgery applies to this procedure... | Co-Surgeons (62) | 0 - Co-surgeons not permitted for this procedure. | Team Surgery (66) | 0 - Team surgeons not permitted for this procedure. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | APC Status Indicator | Procedure or Service, Not Discounted when Multiple | Type of Service (TOS) | Q - Vision Items or Services | Berenson-Eggers TOS (BETOS) | none | MUE | 1 |
| 51 | Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d). | GW | Service not related to the hospice patient's terminal condition | 26 | Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number. | TC | Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | 52 | Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | RT | Right side (used to identify procedures performed on the right side of the body) | 24 | Unrelated evaluation and management service by the same physician or other qualified health care professional during a postoperative period: the physician or other qualified health care professional may need to indicate that an evaluation and management service was performed during a postoperative period for a reason(s) unrelated to the original procedure. this circumstance may be reported by adding modifier 24 to the appropriate level of e/m service. | 25 | Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service: it may be necessary to indicate that on the day a procedure or service identified by a cpt code was performed, the patient's condition required a significant, separately identifiable e/m service above and beyond the other service provided or beyond the usual preoperative and postoperative care associated with the procedure that was performed. a significant, separately identifiable e/m service is defined or substantiated by documentation that satisfies the relevant criteria for the respective e/m service to be reported (see evaluation and management services guidelines for instructions on determining level of e/m service). the e/m service may be prompted by the symptom or condition for which the procedure and/or service was provided. as such, different diagnoses are not required for reporting of the e/m services on the same date. this circumstance may be reported by adding modifier 25 to the appropriate level of e/m service. note: this modifier is not used to report an e/m service that resulted in a decision to perform surgery. see modifier 57 for significant, separately identifiable non-e/m services, see modifier 59. | 53 | Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | 76 | Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 77 | Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 79 | Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.) | AQ | Physician providing a service in an unlisted health professional shortage area (hpsa) | CC | Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed) | CR | Catastrophe/disaster related | E2 | Lower left, eyelid | GA | Waiver of liability statement issued as required by payer policy, individual case | GC | This service has been performed in part by a resident under the direction of a teaching physician | GY | Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit | GZ | Item or service expected to be denied as not reasonable and necessary | LT | Left side (used to identify procedures performed on the left side of the body) | Q6 | Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
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