1. Which of the following is not true regarding serous choroidal detachment.
a. Precipitating factor is usually hypotony
b. Surgical intervention is needed for most of the cases
c. It leads to low IOP with shallow anterior chamber
d. All of the above.
2. Which among the following is a complication of bleb needling.
a. Hypotony .
b. Choroidal haemorrhage
c. Choroidal effusion
d. All of the above
3. Which of the following is treatment modality for encysted bleb.
a. Bleb needling
b. Surgical excision of the cystic wall with application of mitomycin C
c. Valve removal and reimplantation in another site
d. All of the above
4. True regarding histological feature of encapsulated ble
a. Outer surface consist of tightly packed collagen
b. Transformation of fibroblasts into myofibroblasts is seen in outer layer
c. Pseudo-endothelium is formed towards base of plate
d. All of the above
5. Which of the following statement is true regarding bleb encystment
- It develops when Tenon’s capsule adheres to the episclera
- Results in IOP elevation
- Results in decreased IOP.
- a and d
- a and b
QuizWise 2 responses
Answer 1 b (Surgical intervention is needed for most of the cases.)
Causes for low intraocular pressure with shallow or flat anterior chamber in postoperative condition are conjunctival wound leaks and serous choroidal detachments.The precipitating factor for the serous choroidal detachment is usually hypotony. Most cases usually resolve on conservative therapy that consists of frequent topical steroids and cycloplegics with or without systemic steroids along with management of the event precipitating hypotony.
Reference: Vijaya L, Manish P, Ronnie G, Shantha B. Management of complications in glaucoma surgery. Indian journal of ophthalmology. 2011 Jan;59(Suppl1):S131. doi: 10.4103/0301-4738.73689
Answer 2. D. all of the above
A major complication of needling—with an incidence reported between 15–30%—is postoperative hypotony, especially if the scleral flap has to be lifted during the needling procedure. Typical signs of hypotony are flattening of the anterior chamber, overfiltration and choroidal effusion. One major complication is vision-threatening choroidal hemorrhage. Late ocular hypotony may cause maculopathy, chorioretinal folds of the posterior pole, tortuosity of the retinal vessels and visual loss.
Reference: Laspas P, Culmann PD, Grus FH, Prokosch-Willing V, Poplawksi A, Pfeiffer N, Hoffmann EM. A new method for revision of encapsulated blebs after trabeculectomy: combination of standard bleb needling with transconjunctival scleral flap sutures prevents early postoperative hypotony. PloS one. 2016;11(6).doi: 10.1371/journal.pone.0157320
Answer 3. D (all of the above)
An encapsulated cyst (also called Tenon’s cyst) develops when Tenon’s capsule adheres to the episclera, forming a high, domed, smooth, two-layered bleb. The encapsulated cyst is impermeable to aqueous humour, which results in IOP elevation. The treatment options in these cases include needling and mitomycin C usage but with limited success, surgical excision of the cystic wall with application of mitomycin C, or valve removal and reimplantation in another site.
Reference: Al-Mosallamy SM. Decapsulation versus valve re implantation in cases with an encysted Ahmed valve in refractory glaucoma. Delta Journal of Ophthalmology. 2015 Jan 1;16(1):22. http://djo.eg.net/article.asp?issn=1110-9173;year=2015;volume=16;issue=1;spage=22;epage=26;aulast=Al-Mosallamy
Answer 4. c. Pseudoendothelium is formed towards base of plate.
The cystic wall of these encapsulated blebs (EBs) had an overall thickness of 1.5-2 mm. Histopathologically, the smooth inner surface (facing the base plate of the AGV) consisted of tightly packed collagen fibers with signs of elastoid degeneration, and formation of a pseudoendothelium toward the base plate. There was pronounced transformation of fibroblasts into myofibroblasts in this inner layer. The outer layer was highly vascularised. In these vessels electron microscopy revealed thrombosis.
Reference: Al-Mosallamy SM. Decapsulation versus valve re implantation in cases with an encysted Ahmed valve in refractory glaucoma. Delta Journal of Ophthalmology. 2015 Jan 1;16(1):22. http://djo.eg.net/article.asp?issn=1110-9173;year=2015;volume=16;issue=1;spage=22;epage=26;aulast=Al-Mosallamy
Answer 5. e -both a and b
An encapsulated cyst (also called Tenon’s cyst) develops when Tenon’s capsule adheres to the episclera forming a high, domed, smooth, two-layered bleb. The encapsulated cyst is impervious to aqueous humor, which results in IOP elevation. Over time, this barrier may become less dense and the IOP may normalize. With excessive fibrosis and persistent IOP elevation, however, further intervention may be necessary
Reference: Eibschitz-Tsimhoni M, Schertzer RM, Musch DC, Moroi SE. Incidence and management of encapsulated cysts following Ahmed glaucoma valve insertion. Journal of glaucoma. 2005 Aug 1;14(4):276-9.