The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery: report 2, relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture.
OBJECTIVE
To describe the relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture rates in patients undergoing cataract surgery.DesignThe Royal College of Ophthalmologists' National Ophthalmology Database (NOD) study.


METHODS
Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Data parameters included: demographics, biometry, ocular copathology, visual acuity measurements, and surgical complications including posterior capsule rupture, or vitreous loss or both (PCR).


RESULTS
Consultant surgeons performed a higher proportion of operations on eyes whose axial length were at the extremes. Glaucoma and age related macular degeneration were more common in eyes with shorter axial lengths, whilst previous vitrectomy was associated with longer axial lengths. Eyes with brunescent or white cataracts or amblyopia were more common at both axial length extremes. Preoperative visual acuities were similar for eyes with axial length measurements up to approximately 28 mm and worse for eyes with longer axial length measurements. PCR rates showed little change with axial length (overall mean 1.95%, 95% CI: 1.89 to 2.01%), except for a borderline increase in eyes with axial length <20.0 mm where rates were 3.6% (95% CI: 2.0 to 6.3%). The likelihood of PCR in eyes with axial length <20.0 mm was 1.88 times higher than those of ≥20.0 mm (P=0.0373).


CONCLUSIONS
Rates of ocular comorbidities vary by axial length. PCR rates in eyes with very short or long axial lengths were lower than expected.
The NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
A C
AC
Day
The Royal College of Ophthalmologists' National Ophthalmology Database, Euston, London, UK.|Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, UK.
P H J
PH
Donachie
The Royal College of Ophthalmologists' National Ophthalmology Database, Euston, London, UK.|Bristol Eye Hospital, Bristol, Bristol, UK.
J M
JM
Sparrow
The Royal College of Ophthalmologists' National Ophthalmology Database, Euston, London, UK.|Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, UK.
R L
RL
Johnston
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058452:Axial Length, Eye / Q000473:pathology*; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D016208:Databases, Factual; D005128:Eye Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009885:Ophthalmology / Q000706:statistics & numerical data*; D057851:Posterior Capsular Rupture, Ocular / Q000453:epidemiology*; D057234:Preoperative Period; D011446:Prospective Studies; D012955:Societies, Medical; D006113:United Kingdom; D014792:Visual Acuity / Q000502:physiology*; D014822:Vitreous Body / Q000473:pathology