Abstract
Purpose:
The ability to discern contrast is an important aspect of vision. Cataracts affect this ability. Presently, a frequently used method to determine contrast sensitivity (CS) is the Pelli-Robson Chart (P-R), which evaluates central CS based on the ability to read Sloan Letters, organized into triplets of decreasing contrast. The Spaeth/Richman Contrast Sensitivity (SPARCS) test uses alternate black and white square wave bars, which test CS centrally and also in four peripheral quadrants. The purpose of the present study is to compare the results of determining CS using PR and SPARCS in healthy controls and in those with cataract.
Methods:
Patients with cataract and age-matched normal controls were prospectively evaluated using PR and SPARCS, version H2/H3. Testing was performed in each eye separately in a standardized testing environment. SPARCS contrast scores were determined for central, right upper (RUQ), right lower (RLQ), left upper (LUQ) and left lower quadrants (LLQ). PR and SPARCS scores for each area of vision in cataract patients were compared with age-matched controls.
Results:
Forty-three eyes from 23 patients and 119 eyes from 61 controls were analyzed. The mean scores for SPARCS in the center quadrant were 13.4 and 14.44 in the cataract and control groups, respectively (p<0.001). PR mean scores were 1.32 and 1.45 in the cataract and control groups, respectively (p<0.001). Intraclass correlation coefficients for patients with cataract were 0.76 for PR and 0.61 for SPARCS. There was excellent agreement between the ability of PR and SPARCS to detect the effect of cataract on central CS.
Conclusions:
This study illustrates the significant influence of cataract on CS, both centrally and peripherally. SPARCS offers the advantage of determining contrast peripherally as well as centrally. SPARCS is a user-friendly, highly specific and sensitive method of determining CS, without influence of effects of visual acuity or literacy.
Keywords: 445 cataract •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques •
478 contrast sensitivity