Indian Journal of Ophthalmology

BRIEF COMMUNICATION
Year
: 2010  |  Volume : 58  |  Issue : 1  |  Page : 59--60

Pseudo-gonio synechia: An artifact on two-mirror gonioscopy


Chandra Sekhar Garudadri 
 LV Prasad Eye Institute, Kallam Anji Reddy Campus, LV Prasad Marg, Banjara Hills, Hyderabad - 500 034, India

Correspondence Address:
Chandra Sekhar Garudadri
LV Prasad Eye Institute, Kallam Anji Reddy Campus, LV Prasad Marg, Banjara Hills, Hyderabad - 500 034
India

Abstract

Gonioscopy is an important component of evaluation of any glaucoma patient. Goldmann two-mirror and Sussman or Zeiss four-mirror are the commonly used gonioscopes. Presence of synechia in the angle is diagnostic of angle closure disease in an occludable angle. A patient with pseudo-goniosynechia that disappeared on indentation gonioscopy with Sussman lens but persisted with manipulation gonioscopy with a Goldmann lens is reported.



How to cite this article:
Garudadri CS. Pseudo-gonio synechia: An artifact on two-mirror gonioscopy.Indian J Ophthalmol 2010;58:59-60


How to cite this URL:
Garudadri CS. Pseudo-gonio synechia: An artifact on two-mirror gonioscopy. Indian J Ophthalmol [serial online] 2010 [cited 2020 Apr 9 ];58:59-60
Available from: http://www.ijo.in/text.asp?2010/58/1/59/58473


Full Text

Gonioscopy is an essential part of the work up for proper diagnosis and classification of glaucoma. The visualization of the angle would vary depending on the optics and the mechanics of lens used. Indentation gonioscopy has been advocated to differentiate between appositional and synechial closure of the angle. [1] Variations in gonioscopic techniques are evident from the published epidemiological studies of glaucoma. [2],[3],[4],[5],[6],[7] As per the World Glaucoma Association's (WGA) consensus statement "The best lens to use remains controversial. Many specialists say that the use of a four-mirror lens is mandatory. Many others disagree. Many closed angles can be "manipulated" open using a Goldmann lens. However, a small proportion of appositionally closed angles cannot. In these cases, the use of a four-mirror lens is mandatory. For this reason, the minimum standard is a four-mirror lens." [8] In this report we present an additional benefit of indentation gonioscopy.

 Case Report



A 45-year-old female patient presented for a routine ophthalmic evaluation. Her visual acuity was 20/20 in each eye without correction, the intraocular pressure was 15 mm Hg in both eyes. The anterior segment examination was unremarkable, with a deep anterior chamber. She underwent gonioscopy as a part of routine complete evaluation. [Figure 1] A, B show the gonioscopic appearance of the angle with what looks like a typical goniosynechia in a wide open angle both with Goldmann (two-mirror) and Sussman (four-mirror) gonioscope. Indentation with the Sussman lens results in the disappearance of the synechia [Figure 2]A as opposed to the Goldmann lens where in spite of the patient looking towards the mirror, with increased illumination and height of slit beam as well as "manipulation", the "synechia" persists [Figure 2]B. This finding we believe is due to a bulge in the periphery of the iris close to the iris insertion, which viewed end-on in gonioscopy looks like a synechia. Indentation flattens the peripheral iris and the bulge making the "synechia" disappear.

 Discussion



The WGA consensus statement reiterates the difference of opinion among specialists about the ideal gonioscope. [8] The published epidemiological studies on angle closure glaucoma have used varying gonioscopic techniques. There have been two population-based studies in Singapore and Mongolia. [2],[3] In a report looking at the relationship between peripheral anterior synechia (PAS) and angle width the authors found the prevalence of synechiae in wide open angles to vary from 1.88% (Mongolia) to 3.68% (Singapore). [4] In the three epidemiological studies from South India, the prevalence of primary angle closure (PAC) varied from 0.71 to 4.32%. [5],[6],[7] It is possible that the differences in the prevalence of angle closure [5],[6],[7] may in part be due to the differences in methodology of gonioscopy. While manipulative gonioscopy can open the angle in 90-95% of cases, indentation is necessary in the rest. [1] In this case documenting the differentiation of true from pseudo-synechia was possible by indentation gonioscopy with a four-mirror and not by manipulative gonioscopy by a Goldmann gonioscope. We believe that this is an additional advantage of indentation gonioscopy, and indentation gonioscopy is essential to differentiate between pseudo and true goniosynechia.

References

1Thomas R, Thomas S, Chandrashekar G. Gonioscopy. Indian J Ophthalmology 1998;46:255-61.
2Foster PJ, Baasanhu J, Alsbirk PH, Munkhbayar D, Uranchimeg D, Johnson GJ. Glaucoma in Mongolia - A population-based survey in Hovsgol province, northern Mongolia. Arch Ophthalmol. 1996;114:1235-41.
3Foster PJ, Francis TS, Machin OD, Tze-Pin Ng, Joe G, Devereux, et al. The Prevalence of Glaucoma in Chinese Residents of Singapore: A Cross-Sectional Population Survey of the Tanjong Pagar District, Arch Ophthalmology. 2000;118:1105-11.
4Foster PJ, Aung T, Nolan WP, Machin D, Baasanhu J, Khaw PT, et al. Defining "occludable" angles in population surveys: drainage angle width, peripheral anterior synechiae, and glaucomatous optic neuropathy in east Asian people. British J Ophthalmology 2004;88:486-90..
5Jacob A, Thomas R, Koshi SP, Braganza A, Muliyil J. Prevalence of primary glaucoma in an urban South Indian population. Indian J Ophthalmology 1998;46:81-6.
6Dandona L, Dandona R, Mandal P, Srinivas M,. John RK,. McCarty CA. et al Angle-closure glaucoma in an urban population in southern india. The andhra pradesh eye disease study. Ophthalmology 2000;107:1710-6.
7Vijaya L, George R, Arvind H, Baskaran M, Ramesh VS, Raju P, et al. Prevalence of primary angle-closure disease in an urban south Indian population and comparison with a rural population. The Chennai Glaucoma Study. Ophthalmology. 2008;115:655-60.
8Foster PJ, He M, Liebmann JF. Epidemiology, classification and mechanism. In: Angle closure and angle closure glaucoma. The Hague, Netherlands: Kugler Publications; 2006. p. 15.