Dear Editor,

We read with interest the article Full thickness eyelid transsection (blepharotomy) for upper eyelid lengthening in lid retraction associated with Graves’ disease by Hintschich.[1] This prospective study showed that full thickness eyelid transsection with preservation of central conjunctival bridge leaded to perfect or acceptable surgical results in 57 of 60 lids after one or two surgical procedures.

It becomes increasingly common, as in this study, to cut the lateral horn of levator aponeurosis to relieve the temporal flare of upper eyelid retraction in Graves' disease.[2] The lateral horn, however, bears close anatomical relationship with the palpebral lobe of lacrimal gland that may be damaged during upper eyelid surgery without careful dissection. We are concerned that the risk may become more significant during full thickness eyelid transsection because the anatomical details of the lateral horn and its surrounding structure may be relatively less defined. Furthermore, it has been shown that lacrimal production may be reduced after mullerectomy by the conjunctival approach.[3] Despite no patients complained of dry eye symptoms in this study, which may be partly attributable to improvement in symptoms related to eyelid retraction, more objective assessment in this respect seems warranted.

Upper eyelid retraction is frequently accompanied by prominent preaponeurotic fat in Graves’ ophthalmopathy. Levator recession by the transcutaneous approach can simultaneously manage both of these by opening the orbital septum. Since no patient in this study received fat removal, we would like to know if the authors would recommend, if required, simultaneous fat removal by opening the orbital septum or staged surgery.

We congratulate the valuable work by Hintschich and associate and hope that further discussion would broaden our understanding of this remarkable surgical technique for upper eyelid retraction.

References

1. Hintschich C, Haritoglou C. Full thickness eyelid transsection (blepharotomy) for upper eyelid lengthening in lid retraction associated with Graves’ disease. Br J Ophthalmol 2005;89:413-6.

2. Mourits MP, Sasim IV. A single technique to correct various degrees of upper lid retraction in patients with Graves’ orbitopathy. Br J Ophthalmol 1999;83:81-4.

3. George JL, Tercero ME, Angioi-Duprez K, Maalouf T. Risk of dry eye after mullerectomy via the posterior conjunctival approach for thyroid- related upper eyelid retraction. Orbit 2002;21:19-25.

Dear Editor,

Dr. Fernandez Rubio raised an interesting issue of "climatic factor" as a risk for delayed onset endophthalmitis after glaucoma surgery. He asked whether the onset of endophthamitis due to Hemophilus influenzae and Streptococcus pneumonia took place around a particular part of the year in our study.[1] We did not look into the issue of climatic factor during our review. However, charts of those patients who developed endophthalmitis caused by H. influenzae and S. pneumonia organisms were reviewed recently, and it appears they did not take place during a particular part of the year.

Organisms causing endophthalmitis following glaucoma drainage implant (GDI) surgery in children are H. influenzae or S. pneumonia or both. In our series,[1] cultures revealed S. pneumonia in 2 eyes, H. influenzae in 1 eye, and both organisms in 1 eye. Gedde et al,[2] and Al-Torbaq and Edward[3] reported H.influenzae caused endophthalmitis following GDI surgery in 2 separate paediatric patients. This is not surprising as H. influenzae and S. pneumonia are part of the normal bacterial flora of the conjunctiva and upper respiratory tract, and a common cause of infection in both tissues.[4,5] Presence of conjunctival erosion which is common in paediatric shunts (10-13%),[6] is a major risk factor for endophthalmitis. Prompt surgical revision of an exposed GDI tube is highly recommended.

Abdullah A. Al-Torbak, MD, FRCS
King Khaled Eye Specialist Hospital
P.O. Box 7191 Riyadh 11462
Saudi Arabia
Tel: +966-1-482-1234 Ext. 3771
Fax: +966-1-482-9311
Email: atorbaq{at}health.net.sa

References

1. Al-Torbak AA, Al-Shahwan S, Al-Jadaan I, et al. Endophthalmitis associated with the Ahmed glaucoma valve implant. Br J Ophthalmol 2005;89:454-458.

2. Gedde SJ, Scott IU, Tabandeh H, et al. Late endophthalmitis associated with glaucoma drainage implants. Ophthalmology 2001;108:1323-1327.

3. Al-Torbaq A, Edward DP. Delayed endophthalmitis in a child following an Ahmed glaucoma valve implant. JAAPOS 2002;6:123-125.

4. Osata MS. Normal Ocular flora. In: Pepose JS, Holland GN, Wilhelmus KR, eds. Ocular infection and immunity. St. Louis: Mosby;1996:191-199.

5. Kaplan SL, Feigin RD. Haemophilus influenzae. In: Behrman RE, Kliegman RM, eds. Nelson Textbook of Paediatrics. 14th ed. Philadelphia: Saunders,1992:711-713.

6. Englert JA, Freedman SF, Cox TA. The Ahmed valve in refractory paediatric glaucoma. Am J Ophthalmol 1999;127:34-42.

Dear Editor,

We read with interest the article by Antcliff and associates.[1] The authors have compared the macular edema, retinal thickness, visual acuity and cyst height in 11 patients of non ischaemic central retinal vein occlusion (niCRVO) randomized to either observation or laser-induced chorioretinal anastomosis (CRA). Although only 6 patients underwent laser induced CRA, the results are encouraging at six months. There are few issues which we would like to raise.

The incidence of CRAs post CRVO is generally 50% during the natural course and these spontaneously arising CRAs were found to develop at a mean interval of 3.9 months by Fuller et al.[2] Also since the retinal haemorrhages present in a fresh case of CRVO may be partly responsible for decreased visual acuity, an early intervention that does not allow normal recovery may be unjustified. We would recommend reassessment of visual acuity and retinal perfusion at 4 to 6 weeks before resorting to any intervention.

The laser-induced CRAs, as described by McAllister et al have been found to improve macular edema in patients of niCRVO.[3] They could successfully create CRAs in only 33% of the cases with one attempt [3], 54% of cases in more than one attempt [4] and in 43% of the cases with mean 1.8 attempts.[5] Since 20% of the eyes also developed the neovascularization at the site of anastomosis [4], it would be interesting to know the total number of attempts required to create a functional anastomosis in all 6 eyes by Antcliff et al.

Also the authors have reported that they could not mask the patients because of the laser surgery, we would suggest a sham procedure on observation group to overcome this limitation. To summarize, the authors are commended for conducting a randomized study for evaluation of this alternative technique to improve vision in CRVO patients. We agree with the authors that a larger trial with longer follow up duration is needed to reach a conclusion. The issues raised by us can also be utilized when planning future studies.

References

1. Antcliff RJ, Mayer EJ, Williamson TH, J S Shilling. Early chorioretinal anastomosis in non-ischaemic CRVO: a randomised trial. Br. J.Ophthalmol. 2005;89;780-781.

2. Fuller JJ, Mason JO, White MF, et al. Retinochoroidal Collateral Veins Protect Against Anterior Segment Neovascularization After Central Retinal Vein Occlusion. Arch Ophthalmol. 2003;121:332-336.

3. McAllister IL, Constable IJ. Laser-induced chorioretinal venous anastomosis for treatment of nonischemic central retinal vein occlusion. Arch Ophthalmol. 1995 Apr;113(4):456-62.

4. McAllister IL, Douglas JP, Constable IJ, Yu DY. Laser-induced chorioretinal venous anastomosis for nonischemic central retinal vein occlusion: evaluation of the complications and their risk factors. Am J Ophthalmol. 1998 Aug;126(2):219-29.

5. Eckstein M, McAllister I. Laser-induced chorioretinal venous anastomosis for non-ischaemic hemi-central vein occlusion. Clin Experiment Ophthalmol. 2000 Feb;28(1):18-21.

Dear Editor,

We read with great interest the article on the new design of a cryoprobe for removal of Orbital tumors.[1] The concept of providing a large spatulated surface for better tumour adhesion is commendable. Cryoextraction greatly facilitates the excision of well-defined, solid, encapsulated, benign or malignant tumors.[2,3] We have been routinely employing cryoextraction for orbital tumors at our centre for a considerable period of time and would like to share our experience on this subject and delve into a few crucial issues.

Indeed, the presently available cryoprobes used for orbital tumour extraction have rounded tips which may not give a very large area for tumour adhesion. However, it is our considered opinion that such probes provide a greater margin of safety when they are applied to masses that are relatively more friable or are cystic in nature. The rounded edges lead to lesser trauma to the tumour capsule and the probability of its rupture is significantly reduced. The spatulated cryoprobe devised by the authors seems to have a sharp edge which may cause disruption of the tumour in these situations.

The authors have descried the use of the new probe in just a single case of a well-encapsulated and circumscribed Cavernous Haemangioma. It would be interesting to know if they have used this probe in other types of orbital lesions of varying consistency and diverse etiologies. The response to the application of a cryoprobe depends on a multitude of factors such as tumour contents, consistency, friability, encapsulation and adhesion to surrounding structures. The safety and effectivity of this newly designed cryoprobe can be objectively assessed only after it has been successfully used in a wider variety of orbital tumours in a larger series of patients.

References

1. Finger PT. "Fingertip" cryoprobe assisted orbital tumour extraction. Br J Ophthalmol. 2005 ; 89(6):777-8.

2. Kiratli H, Bilgic S. Cryoextraction in the management of orbital tumors. An old technique revisited. Orbit. 1998 ; 17(3):189-194.

3. Hurwitz JJ, Mishkin SK. The value of cryoprobe-assisted removal of orbital tumors. Ophthalmic Surg. 1988 ; 19(2):94-7.