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Corneal hysteresis (CH) is a critical biomechanical property of the cornea that reflects its viscoelastic characteristics. This property is assessed through a specialized procedure that involves applying an external shear force to the cornea using a puff of air, which causes the cornea to flatten, a process known as applanation. Following this, an infrared beam is utilized to monitor the changes in the cornea's shape. The measurement of corneal hysteresis is derived from the difference in air pressure during the applanation process, specifically the pressure required to flatten the cornea when the air is applied and the pressure when the air is released. This measurement is significant as it provides insights into the stiffness or rigidity of the cornea and its ability to withstand intraocular pressure (IOP). Corneal hysteresis is particularly valuable in the context of glaucoma management, as it can offer independent information that aids in both the diagnosis and ongoing management of this condition. Additionally, it may assist in identifying eyes that are at an increased risk for developing keratoconus, a progressive eye disease that affects the cornea's shape and thickness. Furthermore, corneal hysteresis measurements can be used in conjunction with topographic assessments to evaluate the geometric properties of the eye. They also play a role in monitoring the accuracy of tonometric devices, providing a corneal compensated intraocular pressure (IOPcc) measurement that is crucial for comprehensive eye care.
© Copyright 2025 Coding Ahead. All rights reserved.
Corneal hysteresis determination is performed for various clinical indications, particularly in the context of assessing corneal health and intraocular pressure management. The following conditions may warrant this procedure:
The procedure for corneal hysteresis determination involves several key steps that ensure accurate measurement and interpretation of the corneal response to applied air pressure. The following procedural steps are typically followed:
After the corneal hysteresis determination procedure, patients may experience minimal discomfort, which typically resolves quickly. There are generally no specific post-procedure care instructions required, as the procedure is non-invasive and does not involve any surgical intervention. However, patients should be advised to report any unusual symptoms or prolonged discomfort to their healthcare provider. The results of the corneal hysteresis measurement will be discussed with the patient during a follow-up appointment, where the implications for their ocular health and any necessary management strategies will be outlined.
| Short Descr | CORNEAL HYSTERESIS DETER | Medium Descr | CORNEA HYSTERESIS DETERMIN IMPULSE STIMJ UNI/BI | Long Descr | Corneal hysteresis determination, by air impulse stimulation, unilateral or bilateral, with interpretation and report | 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 | STV-Packaged Codes | Type of Service (TOS) | Q - Vision Items or Services | Berenson-Eggers TOS (BETOS) | M5C - Specialist - ophthalmology | 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). | GA | Waiver of liability statement issued as required by payer policy, individual case | 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. | 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. | 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). | 57 | Decision for surgery: an evaluation and management service that resulted in the initial decision to perform the surgery may be identified by adding modifier 57 to the appropriate level of e/m service. | 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. | 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. | 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.) | 95 | Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system. | GC | This service has been performed in part by a resident under the direction of a teaching physician | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | GW | Service not related to the hospice patient's terminal condition | GX | Notice of liability issued, voluntary under payer policy | 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 | RT | Right side (used to identify procedures performed on the right side of the body) | 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 |
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