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Review article/Pregledni prispevek

THE BIRMINGHAM EYE TRAUMA TERMINOLOGYSYSTEM (BETT)

BIRMINGHAMSKI TERMINOLOŠKI SISTEM OČESNIH POŠKODB (BETT)

Ferenc Kuhn1, 2, Viktoria Mester2, 3, Robert Morris1, Clark D. Witherspoon1

1 United States Eye Injury Registry, Birmingham, Alabama, U. S. A.2 Department of Ophthalmology, University of Pécs, Hungary

3 Mafraq Hospital, Abu Dhabi, U. A. E.

Arrived 2002-02-28, accepted 2002-03-14; ZDRAV VESTN 2002; 71: Supl. II: 17–9

Ključne besede: poškodbe očesa; klasifikacija

Izvleček – Izhodišča. Analiza uporabe terminologije očesnihpoškodb in izdelava vseobsgajočega a enostavnega sistemapoimenovanja.

Metode. Izčrpen pregled literature v mednarodnih oftalmo-loških revijah.

Rezultati. Razvit je bil nov sistem poimenovanja očesnih pošk-odb pri katerem je referenčni organ vedno oko. Vse vrste pošk-odb so nedvoumno definirane in uvrščene v klasifikacijo.Odmevi kažejo, da je bil predlog klasifikacije v svetu širokosprejet, tako med raziskovalci kot tudi med kliničnimi oftal-mologi; sistem terminologije so sprejela tudi najpomembnejšamednarodna strokovna telesa v oftalmologiji.

Zaključki. BETT ima dobre možnosti, da zamenja tradiciona-lni način poimenovanja očesnih poškodb in tako zagotovi stan-dardizirano osnovo za epidemiološke in klinične študije.

Opomba urednika: Terminologija, ki je predstavljena v članku je mednarodno sprejeta in uveljavljena, zato jo je potrebno uporabljati tudi v Sloveniji. Predvsemopozarja na razliko med izrazom: perforativna rana, ki je po BETT penetrantna rana. Perforativna rana je po BETT tista, ki smo jo doslej imenovali dvojnaperforativna rana.

Key words: ocular trauma; classification

Abstract – Background. To analyze the currently used oculartrauma terms and design a comprehensive yet simple newsystem.

Methods. Extensive survey of the recent international oph-thalmic literature.

Results. A new system to describe globe injuries was designedin which the tissue of reference is always the globe itself. Allinjury types are unambiguously defined and are part of anoverall classification. Early results show that the proposal hasbeen welcomed by practitioners and researchers alike; the sys-tem has also been officially endorsed by several national andinternational organizations.

Conclusions. BETT has a good chance of replacing the indi-vidual interpretation associated with the current terminolo-gy, thereby providing a standardized basis for epidemiologicand clinical practice and research.

IntroductionWithout a standardized terminology of eye injury types, it isimpossible to design projects such as the development of theocular trauma score; clinical trials in the field of ocular traumacannot be planned and the communication between oph-thalmologists remains ambiguous. Multiple literature exam-ples demonstrate the lack of definitions, with obvious impli-cations. For example, »Blunt injury«: If the consequences areblunt, it is a contusion (closed globe injury) (1). If the inflict-ing object is blunt, it is either a contusion or a rupture (openglobe injury) (2). To add to the confusion, the two terms haveeven been thrown together as »contusion rupture« (3). Sincethe word »blunt« is ambiguous and contusion and rupture havevastly different implications, it is best to eliminate »blunt« fromour eye injury vocabulary. »Blunt nonpenetrating globe inju-

ry« (3): Do sharp nonpenetrating injuries also occur? »Bluntpenetrating trauma« (4): Aren’t all penetrating injuries sharp?»Sharp laceration« (5): Is there a laceration that is blunt? »Bluntrupture« (6): Is there a rupture that is sharp?

Development of standardizedclassification of ocular traumaterminologyAn unambiguous system in ocular traumatology must satisfythe following three criteria. 1. Each term has a unique defini-tion. Currently, it is exceptional that definitions in publica-tions are provided at all or that their use is enforced (7). 2. Noterm can be applied for two different injury types. Unfortu-nately, numerous examples show that the same term (»perfo-

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rating«) is used to describe two distinctly different clinicalentities: an injury with a single [entrance] wound (8) or onewith both entrance and exit wounds (9). 3. No injury is de-scribed by different terms. Unfortunately, numerous examplesshow the opposite: an injury with both entrance and exitwounds is referred to as »double penetrating,« (10) »double-perforating,« (11) and »perforating;« (12) or the same injury isalternatively referred to either as penetrating or as perforat-ing – even within the same article (13).Birmingham Eye Trauma Terminology (BETT) satisfies allcriteria by: providing a clear definition for all injury types(Tab. 1).

DiscussionThe key to BETT’s logic is to understand that all terms relate tothe whole eyeball as the tissue of reference. Standardizing inju-ry types also has far-reaching prognostic implications (seeChapter 3). For instance: Many variables characterize an ob-ject (e.g., aerodynamics, kinetic energy) (14). The most im-portant, kinetic energy (E), is determined by the mass (m) andthe velocity (v); E = 1/2 mv2. Blunt objects need higher kineticenergy to enter the eye (rupture) and are thus capable of in-flicting more damage than sharp objects (laceration). Evenwhen the blunt object causes a closed globe injury (contu-sion), the visual consequences can be more devastating (e.g.,choroidal rupture at the fovea) than in eyes with an open globetrauma (e. g., retinal tear).While in BETT, a »penetrating corneal injury« is unambigu-ously an open globe injury with a corneal wound, the sameterm had two potential meanings before: an injury penetrat-ing into the cornea (i. e., a partial-thickness corneal wound: aclosed globe injury) or an injury penetrating into the globe (i.e., a full-thickness corneal wound: an open globe injury). Whenthe tissue of reference changes, the terminology must reflectthat; e. g.: »The intra-ocular foreign body must possess certainenergy to perforate the eye’s protective wall«, the tissue ofreference is obviously the sclera/cornea. If the object pene-trates either of these tissues, it does not become intraocularbut remains intrascleral/corneal. Perforation means that theobject entered the tissue on one side and left it on the otherside.BETT (15) has been endorsed by several organizations suchas the: American Academy of Ophthalmology; InternationalSociety of Ocular Trauma; Retina Society; United States EyeInjury Registry and its 25 international affiliates; Vitreous So-ciety; and the World Eye Injury Registry. BETT it is mandatedby several journals such as: Graefe’s Archives; Journal of EyeTrauma; Klinische Monatsblätter; and Ophthalmology.It is desirable for BETT to also become the language of every-day clinical practice.

References1. Joseph E, Zak R, Smith S, Best W, Gamelli R, Dries D. Predictors of blinding

or serious eye injury in blunt trauma. J Eye Trauma 1992; 33: 19–24.2. Russell S, Olsen K, Folk J. Predictors of scleral rupture and the role of

vitrectomy in severe blunt ocular trauma. Am J Ophthalmol 1988; 105: 253–7.

3. Liggett PE, Gauderman WJ, Moreira CM, Barlow W, Green RL, Ryan SJ. Parsplana vitrectomy for acute retinal detachment in penetrating ocular injuries.Arch Ophthalmol 1990; 108: 1724–8.

4. Meredith TA, Gordon PA. Pars plana vitrectomy for severe penetratinginjury with posterior segment involvement. Am J Ophthalmol 1987; 103:549–54.

5. De Juan E, Sternberg P Jr., Michels RG. Penetrating ocular injuries. Ophthal-mology 1983; 90: 1318–22.

6. Klystra JA, Lamkin JC, Runyan DK. Clinical predictors of scleral rupture afterblunt ocular trauma. Am J Ophthalmology 1993; 115: 530–5.

7. Alfaro V, Liggett P. Vitrectomy in the management of the injured globe. In:Philadelphia: Lippincott Raven, 1998.

Tab. 1. Terms and definitions in BETT.*

Tab. 1. Izrazoslovje in definicije BETT.*

Term Definition and explanationIzraz Definicija in razlaga

Sclera and cornea.Beločnica in roženica.

Though technically the eyewall has three coats poste-rior to the limbus, for clinical and practical purposesviolation of only the most external structure is takeninto consideration.Čeprav ima stena očesa za limbusom tri plasti, je tumišljena zunanja stena (beločnica).

Closed globe injury No full-thickness wound of eyewall.Zaprta poškodba očesa Ni rane skozi vso debelino očesne stene.

Open globe injury Full-thickness wound of the eyewall.Odprta poškodba očesa Prisotna je rana skozi vso debelino očesne ste-

ne.

Contusion There is no (full-thickness) wound.Udarnina Ni rane skozi vso debelino očesne stene.

The injury is either due to direct energy delivery bythe object (e. g., choroidal rupture) or to the changesin the shape of the globe (e. g., angle recession).Poškodba je bodisi posledica direktnega prenosaenergije objekta na oko (npr. ruptura žilnice) ali pata povzroči spremembo oblike zrkla (npr. recesijazakotja).

Lamellar laceration Partial-thickness wound of the eyewall.Lamelarna raztrganina Rana, ki sega delno v očesno steno.

Rupture Full-thickness wound of the eyewall, caused bya blunt object.

Ruptura Rana, ki sega skozi vso debelino očesne stene,povzročena s topim predmetom.Since the eye is filled with incompressible liquid, theimpact results in momentary increase of the IOP. Theeyewall yields at its weakest point (at the impact siteor elsewhere; example: an old cataract wound de-hisces even though the impact occurred elsewhere);the actual wound is produced by an inside-out mecha-nism.Ker je oko napolnjeno z nestisljivo tekočino, udarecpovzroči trenutno povečanje IOP. Stena se predrena najšibkejšem mestu (bodisi na mestu udarca alidrugje; npr. stara rane po operaciji katarakte se lahkoodpre kljub temu, da je udarec na drugem mestu);rana nastane zaradi pritiska od znotraj navzven.

Laceration Full-thickness wound of the eyewall, caused bya sharp object.

Raztrganina Raztrganina skozi vse plasti očesa, ki jo po-vzroči oster predmet.The wound occurs at the impact site by an outside-inmechanism.Rana nastane na mestu udarca zaradi vpliva pred-meta od zunaj.

Penetrating injury Entrance wound.Penetrantna poškodba Prisotna je vstopna rana.

If more than one wound is present, each must havebeen caused by a different agent.Če je prisotnih več vstopnih ran, je bila vsaka po-vzročena z drugim predmetom.Retained foreign object/s.Prisoten/ni tujek/i v očesu.Technically a penetrating injury, but grouped sepa-rately because of different clinical implications.Gre za penetrantno poškodbo, vendar za ločenoskupino zaradi različnih kliničnih implikacij.

Perforating injury Entrance and exit wounds.Perforativna poškodba Prisotna je vstopna in izstopna rana.

Both wounds caused by the same agent.Obe rani sta povzročeni z istim predmetom.

* Some injuries remain difficult to classify. For instance, an intravitreal pellet istechnically an IOFB injury. However, since this is a blunt object that requires ahuge impact force if they enter, not just contuse, the eye, there is an element ofrupture involved. In such situations, the ophthalmologist should either describethe injury as »mixed« (i. e., rupture with an IOFB) or select the most serious typeof the mechanisms involved.

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8. Punnonen E, Laatikainen L. Prognosis of perforating eye injuries withintraocular foreign bodies. Acta Ophthalmol 1989; 66: 483–91.

9. Ramsay RC, Knobloch WH. Ocular perforation following retrobulbar anes-thesia for retinal detachment surgery. Am J Ophthalmol 1978; 86: 61–4.

10. Ramsay RC, Cantrill HL, Knobloch WH. Vitrectomy for double penetratingocular injuries. Am J Ophthalmology 1985; 100: 586–9.

11. Topping TM, Abrams GW, Machemer R. Experimental double-perforatinginjury of the posterior segment in rabbit eyes. Arch Ophthalmol 1979; 97:735–42.

12. Hutton WL, Fuller DG. Factors influencing final visual results in severelyinjured eyes. Am J Ophthalmology 1984; 97: 715–22.

13. Hassett P, Kelleher C. The epidemiology of occupational penetrating eyeinjuries in Ireland. Occup Med 1994; 44: 209–11.

14. Dziemian A, Mendelson J, Lindsey D. Comparison of the wounding charac-teristics of some commonly encountered bullets. J Trauma 1961; 1: 341–53.

15. Kuhn F, Morris R, Witherspoon CD, Heimann K, Jeffers J, Treister G. Astandardized classification of ocular trauma terminology. Ophthalmology1996; 103: 240–3.