Ординатура / Офтальмология / Английские материалы / Oculoplasty and Reconstructive Surgery Made Easy_Garg,Touky, Nasralla_2009
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Technique
1.Incision in fornix near limbal side, as it may be posssible to have some conjunctival tissue to cover part of tarsal area or alternatively one can take incision on posterior lower lid boarder. Prefer as much as patients’ own tissue if it is not severely diseased. Dissect and free boarder can be fixed with mattress sutures (Figures 2 to 5).
2.Suture graft material with free boarder of conjunctiva or palpebral lid margin.
Figure 2: Socket surgery |
Figure 3: Incision near lid |
incision near limbal border |
margin |
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Figure 4: Suturing the |
Figure 5: Suturing the |
conjunctiva over tarsal area |
mucosal graft |
3.Place of silicone or silicon rod material at possible site of apex of fornix, and pass mattress sutures from silicon to graft to periostium of lower orbital rim to skin. Tie them with piece of rubber. Minimum 3 mattress sutures are required.
4.Bulbar part of graft fashioned and sutured. Always allow 20 to 25 % extra graft for shrinkage of tissue.
5.Larger graft may need additional mattress sutures passing from graft to superficial sclera.
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6. Examine the fornix for additional sutures.
8.Dressings,
•Surgeon should dress every day and inspect for infection
•Glass rod
•Gentle irrigation
•Prosthesis (Figures 6 to 10)
This case is rare congenital anomaly–a variant of Cryptophthalmos–ankyloblepharon by ankylosis.
Eyelids were partially formed and fused with the eye ball. The visible bulbar conjunctiva was hypermic, chemosed,
Figure 6: Placement of silicone rod in lower fornix
492 Oculoplasty and Reconstructive Surgery
Figure 7: Conjunctiva Incision |
Figure 8: Conjunctival and |
|
mucosal graft suturing |
Figure 9: Fixing silicon rod in lower fornix with mattress sutures fix over the skin with rubber pieces
Figure 10: Placement of plastic shell or confirmer placed in socket
edematous and dry, the eye appeared on first impression as buphthalmic or exophthalmic eye.
The patient was operated jointly by ophthalmologist and plastic surgeon for reformation of fornix with amniotic member graft (Figures 11 to 15).
The results of fornix reconstruction is very rewarding surgery and one must prepare for good post operative care.
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Figure 11: Patient looking up and looking down with artificial eye
Figures 12 and 13: Cryptophthalmos—Ankyloblepharon by ankylosis before surgery
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Figure 15: Cryptophthalmos—Ankyloblepharon by ankylosis after surgery
INTRODUCTION
Periocular sebaceous gland carcinomas (SGCs) occur in the eyelids either sporadically or as a phenotypic feature of MuirTorre syndrome (MTS).
Muir-Torre syndrome is is currently considered a subtype of the more common hereditary nonpolyposis colorectal cancer syndrome, in which multiple primary malignancies occur together with sebaceous gland tumors.1
Lynch syndrome or hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal-dominant disorder characterized by predisposition to colorectal cancer and extracolonic malignancies, frequent multiple primary tumors in the same patient, and early age of cancer onset.
EPIDEMIOLOGY2
Cutaneous SGC incidence rates (IRs) and IR ratios were examined in 9 US Surveillance, Epidemiology, and End Results Program registries (1973-2003) and 95% confidence intervals (95% CIs) calculated for subsequent cancers among 2-month survivors of SGC and for subsequent SGC after other primary cancers. This data showed that, nearly 90% cases are diagnosed among whites (IR, 0.11 per 100,000 person-years), with significantly lower IR were noted among blacks (IR, 0.04).
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Eyelid SGC IRs showed no sex differences and stabilized in recent years. Survivors of SGC had a 43% (95% CI, 15%-76%) increased risk of subsequent cancer, and risk of SGC was elevated by 52% (95% CI, 24%-84%) among survivors of other cancers. Patterns suggestive of genetic predisposition included more than 20-fold risks for early-onset (diagnosed in patients aged less than 50 years) SGC associated with colon, pancreatic, ovarian, or uterine corpus cancers, whereas lateonset SGC (diagnosed in patients aged >/=50 years) predisposed to ureter cancer.2
GENETICS
Patients with MTS showed microsatellite instability(MSI) characteristic for hereditary nonpolyposis colorectal cancer (HNPCC), which is caused by autosomal dominant inherited DNA mismatch repair (MMR) defects. Mutational analyses of the MMR genes hMSH2 and hMLH1 have revealed different germline mutations in the hMSH2 gene. In some cases a truncating germline mutation is seen in the MMR gene hMLH1. The defect is thought to be the result of a mutation in mismatch repair genes and associated with microsatellite instability.3, 4 It is caused by either a mismatch-repair (MMR) defect or inactivation of the fragile histidine triad (FHIT) gene which is associated with MTS-like signs, including SGC. The genetic alterations are associated with microsatellite instability (MSI) and inactivation of the FHIT gene. Loss-of-function mechanisms affecting the FHIT gene are identified as intragenic deletions eliminating the coding exons 5 and 6 on one hand, and complete biallelic methylation of the FHIT transcription regulatory region on the other hand. Either
SGC and Muir–Torre’s Syndrome 497
somatic inactivation of the FHIT gene associated with MSS or inactivation of the MMR system resulting in MSI contribute to the development of periocular SGCs in presumptive.5
Second Hit Theory
Microsatellite instability in tumor tissue develops after somatic inactivation of the corresponding second mismatch repair allele (“second hit”). sebaceous tumors from patients with genetically proven Muir-Torre syndrome the loss of heterozygosity most probably is not the preferred mode of somatic inactivation of the second MSH2 allele.
Duplication
In some cases duplication of exon 7 of the MSH2 gene in MTS is seen.14
Immunohistopathologic Correlation
MSI correlates with loss of MSH2 and MLH1 immunostaining.
Epithelial markers—CEA, EMA30 (Figure 1)
Figure 1
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GENETICOPATHOLOGICO-CLINICAL CLASSIFICATION
Moreker-Kataria-Lala Classification of Sebaceous
Gland Carcinomas
A.Lynch syndrome. No probable second hit.
B.Miur-Torre syndrome—Cystic sebaceous carcinomaprobable second hit—Cystic sebaceous tumors (CST) are well-circumscribed, large, deeply located dermal sebaceous proliferations with a cystic growth pattern. MLH1 and MSH2 gene mutations have an equivalent etiopathological role both for Lynch syndrome and for MTS.7
1.The most common is a variant of hereditary nonpolyposis colorectal cancer, which is characterised by defects in mismatch repair genes and early-onset tumors.
2.The second type does not show deficiency in mismatch repair and its pathogenesis remains undefined.18
C.Sebaceous carcinoma in nevus sebaceus of Jadassohn
D.Pagetoid tumors lid.
E.Conjunctival and lid sebaceous carcinoma
F.Caruncle Sebaceous carcinoma.
G.Collision sebaceous and basal cell carcinomas of the eyelid or kissing tumors sebaceous and basal cell carcinoma.
PRESENTATIONS
Vary from a yellow-pink nodule with telangiectatic vessels on the left lower eyelid in some patient and a yellowish-red, pedunculated lesion with intrinsic vascularization on the right superior tarsal conjunctiva in another to a pagetoid spread or cystic in Muir-Torre syndrome (Figures 2A and B).