Higher-order aberrations of lenticular opacities.
OBJECTIVE
To measure and quantify higher-order aberrations induced by different types of lenticular opacities.


METHODS
Department of Ophthalmology, University of Auckland, and Department of Ophthalmology, Auckland Public Hospital, Auckland, New Zealand.


METHODS
Patients with lenticular opacities were recruited from outpatient clinics of a major tertiary referral center for ophthalmology. Patients were included if they had clinically evident, mild to moderate lenticular opacity with no coexisting ocular pathology. Patients were examined using standard preoperative techniques with additional assessment by wavefront aberrometry (Zywave, Bausch & Lomb) and Scheimpflug photography (EAS-1000, Nidek). For comparison, 20 eyes of 10 subjects with no lenticular opacity (control group) were recruited and assessed in an identical manner.


RESULTS
Thirty persons were recruited and 40 eyes assessed, 20 with lenticular opacities. Ten eyes had predominantly cortical opacification, and 10 had mainly nuclear opacification. In eyes with predominantly cortical opacification, the mean logMAR uncorrected visual acuity (UCVA) was 0.5 +/- 0.2 (SD) (6/18 Snellen equivalent) and the mean logMAR best spectacle-corrected visual acuity (BSCVA), 0.2 +/- 0.2 (6/9). Analysis of aberrometry data for a 6.0 mm pupil in this group revealed an increase in coma of cosine phase (Z(3), P =.06) and tetrafoil of cosine phase (Z(4), P =.07) compared to eyes in the control group. Eyes with predominantly nuclear opacification had a mean logMAR UCVA of 0.7 +/- 0.2 (6/30) and a logMAR BSCVA of 0.4 +/- 0.2 (6/15). Aberrometry data for this cohort for a 6.0 mm pupil showed a statistically greater amount of spherical aberration (Z(4)(0), P =.001) and tetrafoil of cosine phase (Z(4), P =.005; Z(4)(-4), P =.004).


CONCLUSIONS
This pilot study suggests that different types of early lenticular opacities induce different wavefront aberration profiles. Predominantly cortical opacification produced an increase in coma and nuclear opacification induced an increase in spherical aberration compared to eyes without opacities. Both types of lenticular opacities also induced a higher amount of tetrafoil. This could explain the significant visual symptoms in patients with early cataract and relatively good high-contrast Snellen acuity.
Sachdev
Nisha
N
Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
Ormonde
Susan E
SE
Sherwin
Trevor
T
McGhee
Charles N J
CN
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000150:complications* / Q000473:pathology; D019781:Corneal Topography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis / Q000209:etiology*; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology*; D014792:Visual Acuity