Introduction

Of all the subspecialties within ophthalmology, refractive surgery may be the most rapidly evolving. The language associated with visual acuity assessments is likewise changing in an effort to clarify intended meanings. With this edition, the BCSC Section 13 Committee introduces a switch in the manner in which the Section refers to the assessment of corrected and uncorrected visual acuity to reflect trends in the ophthalmic literature. Where the Section used the term best-corrected visual acuity (BCVA) in previous editions, it will now use corrected distance visual acuity (CDVA). Similarly, uncorrected visual acuity (UCVA) will be replaced by uncorrected distance visual acuity (UDVA). A visual acuity conversion chart is available on the inside front cover.

Refractive surgeons, as in all medical specialties, also use numerous abbreviations and acronyms in discussing and describing their field, especially for the continually emerging and changing refractive procedures. Thus, this edition also debuts another addition: the following list of frequently used terms as an aid to readers while reading this text as well as the refractive surgery literature in general.

Abbreviations and Acronyms Common to Refractive Surgery

ACS anterior ciliary sclerotomy

AHWP Asian Harmonization Working Party (for device regulation)

AK arcuate keratotomy

ArF argon-fluoride (laser)

ASA advanced surface ablation

BCVA best-corrected visual acuity (replaced by corrected distance visual acuity, CDVA, in this edition)

CCD charge-coupled device

CCL collagen crosslinking (also CXL)

CDVA corrected distance visual acuity (also called best-corrected visual acuity, BCVA)

CE mark Conformité Européene mark (product approval used in European countries, similar to US FDA approval)

CK conductive keratoplasty

CXL collagen crosslinking (also CCL)

D diopter

DLK diffuse lamellar keratitis

Epi-LASIK epipolis laser in situ keratomileusis

Femto-LASIK femtosecond laser in situ keratomileusis

FLEx femtosecond lenticule extraction

GAT Goldmann applanation tonometry

GHTF Global Harmonization Task Force (international medical device regulation)

HDE Humanitarian Device Exemption

Hex K hexagonal keratotomy

Ho:YAG holmium-yttrium-aluminum-garnet (laser)

ICL implantable collamer lens

ICRS intrastromal corneal ring segments

IOL intraocular lens

IOP intraocular pressure

I–S inferior–superior (value)

KC keratoconus

LASEK laser subepithelial keratomileusis

LASIK laser in situ keratomileusis

logMAR base-10 logarithm of the minimum angle of resolution

LRI limbal relaxing incision

LTK laser thermokeratoplasty

Nd:YAG neodymium-doped yttrium aluminum garnet (laser)

OCT optical coherence tomography

PCO posterior capsule opacification

PERK Prospective Evaluation of Radial Keratotomy (study)

PIOL phakic intraocular lens

PISK pressure-induced stromal keratopathy

PKP penetrating keratoplasty

PMD pellucid marginal degeneration

PMMA polymethylmethacrylate

PRK photorefractive keratectomy

PTK phototherapeutic keratectomy

ReLEx refractive lenticule extraction

RGP rigid gas-permeable (contact lenses)

RK radial keratotomy

RLE refractive lens exchange

RMS root mean square

RSB residual stromal bed

corneal power (K) simulation measurements small-incision lenticule extraction

uncorrected visual acuity (replaced by uncorrected distance visual acuity, UDVA, in this edition) uncorrected distance visual acuity (also called uncorrected visual acuity, UCVA)