A lens coloboma is a congenital anomaly of the lens due to the absence of zonular attachments, causing a thicker lenticular area, but a ciliary body, choroid, iris, optic nerve and eyelid abnormalities may coexist. It is usually located in the inferior nasal quadrant of the eye and is caused by the failure of an embryonic fissure to close (due to toxic or inflammatory factors) during the third or fourth months of intrauterine life, but genetic transmission has also been postulated.
Presentation
A lens coloboma presents as a wedge-shaped abnormality that is due to the existence of a peripheral flattening, indentation or defect, usually located in the inferomedial portion of the lens, but superior nasal quadrant involvement has also been described [1]. The structure has an equatorial notch [2]. This can be an only anomaly, being called a primary coloboma, or underlying structures like the uvea may also be affected- and then it is called a secondary coloboma. A typical coloboma occurs at the exact same location where an embryonic fissure is present, whereas an atypical one does not [1] and may be caused by a ciliary body tumor like a medulloepithelioma or following congenital glaucoma surgery [3]. The neighboring area of the lens may become opaque and the lens capsule may become thicker.
The patient presents with visual abnormalities caused by astigmatism, that is, in turn, due to the lens shape abnormality [4]. Lens contraction and dilation are also impaired, due to the absence or loose character of zonules in the affected area.
A lens coloboma may be associated with other ocular abnormalities: retinal detachment, iris, optic disk or choroid colobomas. Abnormalities may also be bilateral, but usually, only one eye is affected [5].
Entire Body System
- Inflammation
Other symptoms that need quick attention are pain, double vision, fluid coming from the eye, and inflammation. [icdlist.com]
In our case, pars plana cataract extraction did not cause peripheral retinal tears, although the eye of the patient was affected by high myopia (10 diopters) and no acute ocular inflammation was found. [ncbi.nlm.nih.gov]
Macular coloboma may be caused when normal eye development is interrupted or following an inflammation of the retina during development of the baby. [nei.nih.gov]
The condition is thought to result from intrauterine inflammation or to be an abnormality of development. [nature.com]
- Weakness
Isolated congenital lens coloboma is a sectoral indentation of the crystalline lens due to zonular weakness or absence. [ncbi.nlm.nih.gov]
However, it is important for children with coloboma to be followed by an eye care professional to: Monitor the need for glasses to correct any refractive errors Treat amblyopia (weakness in one eye) if it occurs, usually by patching or using eye drops [dgckids.org]
Ophthalmologist - retinal specialist Corneal exposure secondary to facial palsy External examination Ophthalmologist Pediatrician Cataracts External examination Ophthalmologist Ptosis (droopy lids) External examination Ophthalmologist Strabismus or amblyopia (weak [chargesyndrome.org]
Preoperatively, assessing the zonular apparatus will be important, because patients like this one often have zonular absence or weakness in the region of the coloboma. [crstoday.com]
FA revealed, in both eyes, a late juxtapapillary and macular staining together with weak hyperfluorescent areas of RPE depigmentation around the posterior pole ( Figure 3c, d ). [nature.com]
- Surgical Procedure
During the surgical procedure an ophthalmic viscosurgical device was used to tamponade the vitreous, and after continuous curvilinear capsulorhexis the capsular tension ring was inserted to allow the surgeon to perform a safe phacoemulsification. © 2012 [karger.com]
Procedures Senile Cataract Toxic Agents, Medication and Radiation Trauma (Injury) Lids Neuro-Ophthalmology Optic Nerve Orbit Retina Sclera Strabismus, Ocular Motility Disorders Systemic Diseases Vitreous Z Videos Z-iPodcasts Z_Op-Videos Endorsed by iPod [atlasophthalmology.net]
Currently, pars plana lensectomy with anterior vitrectomy and TSFIOL assisted with fibrin glue is the surgical procedure of choice.7 Other modalities for management of severe lens subluxation include phacoaspiration and IOL with capsular tension ring or [docksci.com]
- Multiple Congenital Anomalies
Bermejo and associates 3 evaluated 55 eyes with coloboma and found that coloboma occurred in isolation in 15% of cases, with multiple congenital anomalies in 58%, and as part of a multisystem syndrome in 27%. [retinatoday.com]
Eyes
- Strabismus
No strabismus was found. Nasal side deficiency of lens substituted by a membrane was found in the left eye. Normal crystalline lens was noted in the contralateral eye. Lens coloboma with congenital cataract was diagnosed. [austinpublishinggroup.com]
Amblyopia may be treated with patching; strabismus may be treated with surgery. Refractive errors that reduce visual acuity can often be helped with glasses. [chargesyndrome.org]
Single lens to lens duplication: The missing link 1 Cornea Unit, M and J Regional Institute of Ophthalmology, Ahmedabad- 380 016, India 2 Pediatric Ophthalmology and Strabismus Clinic, M and J Regional Institute of Ophthalmology, Ahmedabad- 380 016, India [ijo.in]
J Paediatr Ophthalmol Strabismus. 2004; 41: 302-304 Gogate P.M. Kulkarni S.R. Krishnaiah S. Deshpande R.D. Joshi S.A. Palimkar A. et al. [contactlensjournal.com]
Cataracta Subcapsularis Posterior, see also indentation, impression cataract Postoperative Cases and Surgical Procedures Senile Cataract Toxic Agents, Medication and Radiation Trauma (Injury) Lids Neuro-Ophthalmology Optic Nerve Orbit Retina Sclera Strabismus [atlasophthalmology.net]
- Esotropia
Other features: mention to the examiner that you would like to examine the fundus (fundi) for extension of the coloboma which may involve the choroid and the optic disc the patient may have esotropia (or rarely exotropia) if the coloboma involves the [mrcophth.com]
A 3-1/2-month-old white male manifested left esotropia since birth. On examination, visual acuity was fix-and-follow in both eyes. Slit-lamp exam of both eyes disclosed bilateral leukocoria and 30 prism diopters of alternating esotropia (Figure 1A). [retinatoday.com]
Workup
Ophthalmologic assessment reveals the presence of astigmatic refractive error [2] [1], as well as the possible involvement of underlying structures, such as the choroid, optic disk or optic nerve [6] [7]. The optic disk may be hypoplastic [8]. Other unrelated visual anomalies like cataract may sometimes be diagnosed by the ophthalmologist. Moreover, the general appearance of the patient may be suggestive of Marfan or Marshal syndromes [9] [10]. In these cases, a genetic consultation may be in order. Aside from observing the patient's clinical traits, the genetician may order transforming growth factor β (TGFβ) levels which may be increased [9]. A genetic syndrome may be absent, even if facial dysmorphism is present [5]. Lens colobomas have also been reported in association with Alport-like glomerulonephritis [11], therefore a urinalysis may be in order if history and clinical examination point to that diagnosis.
If the visual abnormality is severe and not immediately addressed, the patient will experience visual decline due to amblyopia, that can be anisometropic, meridional or refractive. If the eyelid is affected by ptosis, the prognosis is even more grim. Overall, visual outcome depends on the presentation timing and the patient's desire to undergo surgery and rehabilitation.
Treatment
CLOSE Medical Disclaimer The medical information on this site is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. [diseaseinfosearch.org]
Treatment After making a 3 mm limbal incision, the colobomatous lens was removed by anterior continuous curvilinear capsulorhexis and lens aspiration. [ncbi.nlm.nih.gov]
Prognosis
The prognosis of visual recovery in cases where visual disability has occurred will depend upon the time of detection (better prognosis inside the sensitive period) and the willingness of the patient to attempt rehabilitation. [journalofoptometry.org]
Prognosis The prognosis for vision depended on the phenotype of the better eye Microphthalmos with cyst has the worst prognosis Coloboma with microcornea and microphthalmos a poor prognosis Coloboma with only microcornea has an intermediate prognosis [slideshare.net]
Prognosis [ 9 ] The prognosis for vision depends on the severity and location of the coloboma (particularly in relation to the optic nerve, macula and maculopapular bundle) and on any complications such as retinal detachment or amblyopia. [patient.info]
Etiology
As such, lens notching can occur secondary to etiologies causing weakened or deficient zonules. Reflex sympathetic dystrophy may develop after an injury to an extremity resulting in severe, persistent pain after the injured tissues have healed. [aaopt.org]
There have been few case reports of double lens; the etiology suggested is metaplastic changes in the surface ectoderm that leads to formation of two lens vesicles and hence resulting in double lens. [ijo.in]
Congenital Cataract Definition Congenital opacity of the crystalline lens usually categorized by location or etiology: Capsular Opacity of the lens capsule, usually anteriorly. [clinicalgate.com]
Treacher Collins syndrome: etiology, pathogenesis and prevention. [eyewiki.aao.org]
Epidemiology
Congenital eye malformations: clinical–epidemiological analysis of 1,124,654 consecutive births in Spain. Am J Med Genet. 1998; 75: 497-504 Doganay S. Emre S. Firat P. Bilateral aniridia lenticular coloboma and snowflake degeneration. [contactlensjournal.com]
Vision can be improved with glasses, contact lenses or even laser eye surgery but may be limited if the retina is affected or there is amblyopia.[5] Epidemiology[edit] The number of cases is around 5 to 7 per 100,000 births, making it a relatively rare [en.wikipedia.org]
Epidemiology Congenital cataracts occur in approximately 1 of 2000 live births. [clinicalgate.com]
Epidemiology of congenital eye malformations in 131,760 consecutive births. Ophthalmic Paediatr Genet. 1992;13(3):179-86. [ Links ] 6 Hovland KR, Schepens CL, Freeman HM. Developmental giant retinal tears associated with lens coloboma. [scielo.br]
Epidemiology Incidence is 5 per 1,00,000 newborns Prevalence is 1 in 10,000 60% are bilateral Molecular genetics deletion in gene which maps to chromosome 7q26. a mutation in the PAX6 g # Warburg M J Med Genet. 1993 Aug;30(8):664-9 4. [slideshare.net]
Pathophysiology
Pathophysiology In the normal eye, optic fissure closes 33 to 40 days after conception. [slideshare.net]
It was Watchel who studied the ocular pathology of Marfan's syndrome in 1966 and noted colobomas of the lens as one of its features. [1] Pathophysiology Coloboma of the lens is an autosomal dominant condition occurring in the 4 th month of development [tnoajosr.com]
Clinical and pathophysiological implications of a bicuspid aortic valve. Circulation. 2002;106(8):900-4. [scielo.br]
Prevention
Relaxing microsphincterotomies are important to prevent an excessively inferiorly positioned aperture after pupilloplasty. [crstoday.com]
Posterior capsulorhexis and anterior vitrectomy on the side of the lens was performed to prevent posterior capsular or anterior hyaloid opacity. [ncbi.nlm.nih.gov]
References
- Onwochei B, Simon J, Bateman J, et al. Ocular Colobomata. Surv Ophthalmol. 2000;43:175-194.
- Bavbek T, Ogut M, Kazokoglu H. Congenital lens coloboma and associated pathologies. Doc Ophthalmol. 1993;83:313-322.
- Khan A, Al-Assiri A. Lens coloboma associated with a ciliary body cyst. Ophthalmic Genet. 2007;28:208-209.
- Vaughn L, Schepens C. Progressive lenticular astigmatism associated with nuclear sclerosis and coloboma of the iris, lens, and choroid: Case report. Ann Ophthalmol 1981;13:25-27.
- Aggarwal A, El-Bash A, Inker S, et al. Symmetrical bilateral lens colobomas in two brothers. J Pediatr Ophthalmol Strabismus. 2004;41(5):302-304.
- Li J, Ma X, Hu Z. Lens coloboma and associated ocular malformations. Eye Sci. 2011;26:108-110.
- Stoll C, Alembik Y, Dott B, et al. Epidemiology of congenital eye malformations in 131,760 consecutive births. Ophthalmic Paediatr Genet. 1992;13(3):179-186.
- Fard A, Traboulsi E. Coloboma of the lens, optic nerve hypoplasia and orbital hemangioma-A possible developmental field defect. Ophthalmic Genet. 1998;19(4):209-212.
- LeBlanc S, Taranath D, Morris S, et al. Multisegment coloboma in a case of Marfan syndrome: another possible effect of increased TGF-beta signaling. J AAPOS. 2014;18:90-92.
- Schlote T, Volker M, Knorr M, et al. Lens coloboma and lens dislocation in Stickler (Marshall) syndrome. Klin Monbl Augenheilkd. 1997;210:227-228.
- Amari F, Segawa K, Ando F. Lens coloboma and Alport-like glomerulonephritis. Eur J Ophthalmol. 1994;4(3):181-183.