QuizWise 9

Q 1. In which of the following classifications of bleb is corkscrew appearance of vessels a factor for grading the bleb?

1. Wuerzburg bleb classification score
2. Mainz bleb classification
3. Moorfield’s bleb grading system
4. Indiana bleb appearance

Q 2. Which of the following is not a treatment option for a leaking bleb? 

1. Contact lens
2. Bleb excision with conjunctival advancement
3. Collagen cross linking
4. Bleb needling

Q 3.Who coined the term filtration surgery

1. De Wecker
2. von Graefe
3. Wescott
4. Kelly

Q 4. What is the concentration of 5 Fluorouracil used intra-operatively in trabeculectomy surgery?

1. 0.2 mg/ml
2. 0.5 mg/ml
3. 20 mg/ml
4. 50 mg/ml

Q 5. Following are complications of hypotony post glaucoma surgery, except?

1. Choroidal effusion
2. Suprachoroidal hemorrhage
3. Hypotonic maculopathy
4. Vitreous misdirectionAnswers A – Wuerzburg classification 

Answers 1: A – Wuerzburg classification

Furrer, S., Menke, M.N., Funk, J. et al. Evaluation of filtering blebs using the ‘Wuerzburg bleb classification score’ compared to clinical findings. BMC Ophthalmol 12, 24 (2012 (https://bmcophthalmol.biomedcentral.com/articles/10.1186/1471-2415-12-24#citeas)

Hoffmann, Esther & Herzog, Daniel & Wasielica‐Poslednik, Joanna & Butsch, Christina & Schuster, Alexander. (2019). Bleb grading by photographs versus bleb grading by slit‐lamp examination. Acta Ophthalmologica. 10.1111/aos.14335. (https://onlinelibrary.wiley.com/doi/full/10.1111/aos.14335)

Wells, A. P., Ashraff, N. N., Hall, R. C., & Purdie, G. (2006). Comparison of Two Clinical Bleb Grading Systems. Ophthalmology, 113(1), 77–83. doi:10.1016/j.ophtha.2005.06.037 (https://www.aaojournal.org/article/S0161-6420(05)00926-7/pdf)

2. D Bleb needling

A. A soft bandage contact lens of 14 mm diameter is a safe and efficacious therapy for an early bleb leak following fornix-based trabeculectomy.

Reference – Wu Z, Huang C, Huang Y, Zhang W, Ma D. Soft Bandage Contact Lenses in Management of Early Bleb Leak Following Trabeculectomy. Eye Sci. 2015;30(1):13‐17. (https://pubmed.ncbi.nlm.nih.gov/26390792/)

B. Bleb excision with conjunctival advancement is a successful procedure for bleb repair, thereby reducing the risk of vision threatening sequelae

Reference – annenbaum DP, Hoffman D, Greaney MJ, et al Outcomes of bleb excision and conjunctival advancement for leaking or hypotonous eyes after glaucoma filtering surgery British Journal of Ophthalmology 2004;88:99-103.(https://bjo.bmj.com/content/88/1/99.citation-tools)

C. Cross linking is a safe and effective long‐term treatment for late‐onset cystic bleb leak on patients who do not require immediate surgical interventions

Reference – Cai Y, Choy BNK, Zhu MM, et al. Prospective study on a novel treatment for leaking cystic bleb: Efficacy and safety of collagen crosslinking. Clin Exp Ophthalmol. 2019;47(6):749‐756. (https://onlinelibrary.wiley.com/doi/full/10.1111/ceo.13520)

3. B – De Weckers

When von Graefe first introduced iridectomy as a treatment for glaucoma, some practitioners noted that the patients who usually had persistent reductions in intraocular pressure (IOP) were those who developed an inadvertent filtering bleb at the site of the surgery. This led De Wecker, in 1882, to suggest that the IOP could be reduced by purposely creating a fistula between the anterior chamber and the subconjunctival tissues. He was the first to use the term “filtering” to describe this egress of fluid from the eye

Reference – Fraser S. Trabeculectomy and antimetabolites. Br J Ophthalmol. 2004;88(7):855‐856. doi:10.1136/bjo.2004.040055 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1772247/)

4. D – 50 mg/ml 

A cellulose sponge soaked in 50 mg/ml of 5-FU is placed between the sclera and the conjunctival flap for five minutes 

Refernce- Yoon PS, Singh K. Update on antifibrotic use in glaucoma surgery, including use in trabeculectomy and glaucoma drainage implants and combined cataract and glaucoma surgery. Curr Opin Ophthalmol. 2004;15(2):141‐146. doi:10.1097/00055735-200404000-00015 (https://pubmed.ncbi.nlm.nih.gov/15021227/)

5. D. Vitreous misdirection

Hypotony can be defined as an IOP below a certain value or the presence of ocular abnormalities associated with low IOP such as choroidal effusion, suprachoroidal hemorrhage, maculopathy, optic nerve edema, shallowing of the anterior chamber with corneal decompensation, cataract formation, loss of vision, and even phthisis

Reference – Yoon PS, Singh K. Update on antifibrotic use in glaucoma surgery, including use in trabeculectomy and glaucoma drainage implants and combined cataract and glaucoma surgery. Curr Opin Ophthalmol. 2004;15(2):141‐146. (https://pubmed.ncbi.nlm.nih.gov/15021227/)