Comparison of ultrasound biomicroscopy and ultrasonographic parameters in eyes with phacomorphic glaucoma and eyes with mature cataract.
OBJECTIVE
To compare data on anatomical and biometric parameters, and their combination, obtained by using ultrasound biomicroscopy (UBM) and A-scan in eyes with phacomorphic glaucoma (PG) and eyes with mature cataract and to determine differences that may predispose to development of PG.


METHODS
Eighty patients (80 eyes) were enrolled in this cross-sectional study. Anterior chamber parameters, namely anterior chamber depth (ACD), angle-opening distance (AOD), iris-lens contact distance (ILCD), and trabecular-ciliary process distance (TCPD), among other parameters, were assessed by UBM (35 MHz), while axial length (AL) and lenticular thickness (LT) were determined by A-scan biometry. Absolute lenticular position (ALP) and relative lenticular position (RLP) were also compared.


RESULTS
The mean AL of eyes with PG was less (P = 0.64) than the mean AL of eyes with mature cataract. The mean ILCD value in eyes with PG (1.30 ± 0.78 mm) was significantly higher (P = 0.0015) than that in eyes with mature cataract (0.86 ± 0.32 mm). The mean AOD value in eyes with PG (0.15 ± 0.10 mm) was significantly lower (P < 0.0001) than that in eyes with mature cataract (0.23 ± 0.06 mm); similarly, the mean RLP value in eyes with PG (0.20 ± 0.02) was significantly lower (P < 0.0001) than that in eyes with mature cataract (0.17 ± 0.02). TCPD showed negative correlation with LT r = -0.514; P = 0.017, r2= 0.264, in eyes with phacomorphic glaucoma and mature cataracts showed significant negative correlation of ILCD with AL (r = -0.575; P = 0.025, r2= 0.330).


CONCLUSIONS
The results of UBM examination suggest that there are multiple mechanisms underlying the pathophysiology of PG, namely crowding of the anterior segment, increased iris-lens contact distance, and a more pronounced anterior shift of the lens. Simultaneous evaluation of anatomic and biometric parameters can improve diagnostic accuracy in predicting cases at risk for PG.
Institute of Ophthalmology, Joseph Eye Hospital, Tiruchirappalli, 620001, Tamil Nadu, India. umasujata@yahoo.com.
Sujata
S
Subbiah
Institute of Ophthalmology, Joseph Eye Hospital, Tiruchirappalli, 620001, Tamil Nadu, India.
Philip A
PA
Thomas
Institute of Ophthalmology, Joseph Eye Hospital, Tiruchirappalli, 620001, Tamil Nadu, India.
C A
CA
Nelson Jesudasan
D000869:Anterior Eye Segment / Q000000981:diagnostic imaging*; D002386:Cataract / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D007908:Lens, Crystalline / Q000000981:diagnostic imaging*; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D014065:Tonometry, Ocular
Biometric parameters; Phacomorphic glaucoma; Primary angle-closure glaucoma; Ultrasound biomicroscopy