Grading nuclear, cortical and posterior subcapsular cataracts using an objective scatter index measured with a double-pass system.
OBJECTIVE
To evaluate objectively intraocular scattering in eyes with nuclear, cortical and posterior subcapsular cataracts by means of an objective scatter index (OSI) obtained from double-pass images. To compare the results with those obtained using clinical conventional procedures.


METHODS
In this prospective, observational, cross-sectional, non-consecutive case series study, 188 eyes with cataracts of 136 patients were analysed (123 eyes had nuclear, 41 eyes had cortical and 24 eyes had posterior subcapsular cataracts). The control group consisted of 117 eyes of 68 healthy patients. Patient examination included subjective refraction, best spectacle-corrected visual acuity (BSCVA), cataract grade using the lens opacities classification system III (LOCS III) and OSI.


RESULTS
We found a decrease in the BSCVA and an increase in the OSI with increasing cataract grade. Statistically significant differences were observed when the OSI of eyes without cataracts and those with different LOCS III were compared. The comparison between the OSI and LOCS III reported good percentages of agreement regarding the number of eyes classified in equivalent levels: 72.4% (nuclear cataracts), 86.6% (cortical cataracts) and 84.3% (posterior subcapsular cataracts). A non-linear regression model was applied between OSI and BSCVA, which resulted in the following multiple correlation coefficients: r=0.878 (nuclear), r=0.843 (cortical) and r=0.844 (posterior subcapsular).


CONCLUSIONS
The results of the study showed that OSI is a useful parameter for evaluating large amounts of intraocular scattering that can be used, in combination with other conventional procedures, as a valuable tool in clinical practice to grade cataracts objectively.
Centre de Desenvolupament de Sensors, Instrumentació i Sistemes (CD6), Universitat Politècnica de Catalunya, Rambla Sant Nebridi 10, 08222 Terrassa, Barcelona, Spain. mvilasec@oo.upc.edu
Meritxell
M
Vilaseca
Maria José
MJ
Romero
Montserrat
M
Arjona
Sergio Oscar
SO
Luque
Juan Carlos
JC
Ondategui
Antoni
A
Salvador
José L
JL
Güell
Pablo
P
Artal
Jaume
J
Pujol
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000145:classification* / Q000473:pathology*; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012029:Refraction, Ocular; D012542:Scattering, Radiation; D012720:Severity of Illness Index; D014792:Visual Acuity