Download Comparison of Ultrasound Biomicroscopic Parameters After Laser

March 2008
Journal Review
111
JOURNAL
REVIEW
Comparison of Ultrasound Biomicroscopic
Parameters After Laser Iridotomy In Eyes
With Primary Angle Closure And Primary
Angle Closure Glaucoma
T Dada, S Mohan, R Sihota, R Gupta, V Gupta and RM Pandey
Eye 2007; 21:956-961
Primary angle-closure glaucoma (PAGG) is the major
form of glaucoma in the Asian population and an important
cause for blindness worldwide. The development of
primary angle closure (PAC) into PACG can be prevented
by performing a laser peripheral iridotomy (LPI).
However, there has been no accurate and objective
documentation of the changes in anterior chamber
angle morphology induced by an LPI in various subtypes
of PACG.
The aim of this study, which was conducted at RP center
AIIMS was to find out changes in anterior segment
morphology after laser peripheral iridotomy in primary
angle closure and primary angle closure glaucoma using
ultrasound biomicroscopy (UBM)
Ninety-three eyes of 93 patients underwent anterior
segment evaluation including gonioscopy, disc
evaluation with +90D lens, applanation intraocular
pressure, and standard achromatic perimetry. A single
trained ophthalmologist took the UBM images pre-and
post-LPI. Trabecular-Iris Angle (TIA), the AngleOpening Distance (AOD 250/500) and the Central
Anterior Chamber depth (ACD) were measured.
The superior TIA widened from mean of 7.54 ± 3.15
to 15.66 ± 6.69O and inferior TIA increased from mean
of 9.0+-4.7to 15.9+-3.7after LPI in PAC.
In PACG the mean superior angle changed from
4.55 ± 2.5to 6.12 ± 3.9 and inferior angle increased
from 4.75 ± 2.0to 7.9 ± 3.7. The mean ACD
increased from 2.19 ± 0.36 to 2.30 ± 0.36 mm in
PAC group with no significant change seen in the
PACG group 1.79 ± 0.32 vs. 1.82 ± 0.33 mm,
(P = 0.13).
According to the authors this study is the first one to
demonstrate clearly that there is widening of the
anterior chamber angle and deepening of the anterior
chamber after LPI in eyes with PAC but there is no
significant change in any of the anterior segment
parameters in eyes with PACG
In conclusion, this ultrasound biomicroscopic study
establishes that LPI opens the narrow angle recess and
deepens the anterior chamber in eyes with PAC but is
not effective in altering the anterior segment
morphology in eyes with PACG
112
Kerala Journal of Ophthalmology
Vol. XX, No. 1
Archipelago Keratitis : A Clinical Variant of
Recurrent Herpetic Keratitis ?
Eric E Gabison, Nicolas Alfonsi, Serge Doan, Louis Racine, Gilles Sultan, Christophe Baudouin, Thanh Hoang-Xuan.
Ophthalmology 2007;114:2000-2005
Herpes simplex keratitis (HSK) is the leading infectious
cause of unilateral corneal blindness in industrialized
countries. During the primary infection, HSK is the
result of viral replication, and it takes on a dendritic
aspect in 50 % of cases.
In this study which was designed as a case series
study, a series of 6 patients with an unusual form of
superficial keratitis were analysed at Department of
Ophthalmology, Foundation Ophthalmologique
A.deRoth-schild and Bichat Hospital, Paris, France.
Here the authors describe a series of 6 patients with
keratitis consisting of foci of epithelial erosions
associated with subepithelial nummular inflammatory
infiltrates and disposed in a radial, centripetal,
archipelago like pattern originating from limbus. All
the patients had a past history of herpetic epithelial
keratitis, herpetic vesicles on the ipsilateral lid or both.
Polymerase chain reaction – based screening for herpes
simplex virus 1 and 2 in corneal scrapings demonstrated
positive results in 2 patients. In vivo corneal confocal
microscopy revealed focal areas of hyperreflective
epithelial cells and hyperreflective subepithelial
dendritic structures overlying activated keratocytes. All
the patients improved with oral valacyclovir treatment
followed by topical steroid therapy.
According to the authors, Archipelago Keratitis may
arise from centripetal progression of marginal HSK. This
clinical pattern may be the result of the migration of
limbal stem cells across the HSV marginal ulcer,
resulting in HSV dissemination toward the center of
the cornea.
To conclude Archipelago Keratitis may be a new clinical
variant of herpetic keratitis, reflecting herpetic
dissemination from limbus to the center of the cornea.
Sterile Endophthalmitis after Intravitreal
Triamcinolone: A Possible Association with
Uveitis
Mehryar Taban, Rishi P. Singh, Jeffrey Yau-Huei Chung, Careen Y. Lowder, Victor l. Perex.
Am J Ophthalmol 2007;144:50-54
Intravitreal injections of Triamcinolone (IVTA) to treat
macular pathologic features have increased
exponentially in frequency in the last few years.
The forms of endophthalmitis described to occur
after IVTA are infectious endophthalmitis,
sterile endophthalmitis, and pseudo endophthalmitis.
The latter is not really endophthalmitis and results when
triamcinolone particles migrate into the anterior
chamber to masquerade as a hypopyon and is more
likely to occur in pseudophakic or aphakic patients or
patients with periphearal iridectomy.
Normally triamcinolone - crystalline, milky liquid,
remains in the vitreous for a few days after injection as
a discrete white cloud with little or no reaction in the
March 2008
Journal Review
surrounding vitreous. However, sterile endophthalmitis
may occur in rare instance. Sterile endophthalmitis is
believed to result from an inflammatory reaction to
either triamicinolone or more likely to its
vehicle. Kenalog-40 the commercial form of
triamcinolone contains 0.99 % benzyl alcohol, 0.75 %
carboxymethylcellulose sodium, and 0.04 % polysorbate
80 in the suspension and the presence of these
chemicals may serve as a potential stimulus for an
inflammatory reaction with the eye.
Factors supporting sterile endophthalmitis include
earlier presentation, lack of pain, and relative rapid
recovery of vision with good prognosis.
The purpose of this study was to report an association
between uveitis and sterile endophthalmitis after
intravitreal triamcinolone acetonide injections.
A retrospective analysis of all patients receiving
intravitreal triamcinolone injection at the Cole Eye
Institute, Ohio US from January 2006 to September
2006 was carried out to evaluate for the occurrence of
bacterial or sterile endophthalmitis. Indication for
treatment, ocular history, best-corrected Snellen visual
acuity and clinical findings were recorded from clinical
charts before injection and at last follow-up.
A total of 310 eyes received intravitreal triamcinolone
injection for various causes.There were no cases of
culture-positive infectious endophthalmitis. There were
Reviewed by
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six cases (1.9 %) of sterile endophthalmitis. Of these
cases, four had prior history of uveitis, whereas only
20 out of the 310 cases had a prior history of uveitis.
All six patients sought treatment within three days of
injection and all recovered rapidly. Presenting visual
acuity was either counting fingers or hand movements.
Median best-corrected visual acuity before injection was
20/100 whereas median final visual acuity was 20/80.
Reported risk factors for developing sterile
endophthalmitis after IVTA injection are pseudophakia
with impaired posterior capsule, diagnosis of CME
resulting from Irvine-Gass syndrome, and prior
vitrectomy.
This study suggests that prior history of uveitis may be
an additional risk factor for developing sterile
endophthalmitis after IVTA injection. Four (67 %) of
six patients with sterile endophthalmitis had history of
uveitis, whereas only 20 (6.4 %) of 310 total patients
who received IVTA had history of uveitis. Thus, in
patients with a history of uveitis, there was an incidence
rate of 20 % (four of 20) compared with 0.68% (two
of 290) for other causes.
In conclusion, an additional risk factor for developing
sterile endophthalmitis after IVTA injection is prior
history of uveitis. Such patients should be advised about
the increased risk and caution should be exercised
before injecting these patients.
Dr Alex Baby DO, DNB. Little Flower Hospital and Research Centre, Angamaly.