A Report On Ectopia Lentis Biology Essay

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Ectopia Lentis is a disease defined as malposition of the lens. It arises from pathology of the zonules causing the lens to be displaced. This disease can arise from many conditions, but is well related to systemic diseases such as Marfans Syndrome. The displacement of the lens causes a wide range of refractive errors; with some individuals needing very little treatment, to others requiring surgery under general anaesthetic. The treatments for this disease involves correcting the refractive error of the patient, the main treatment is prescribing glasses after which, if unsuccessful, surgery is then considered to correct the refractive error.

I aim to cover in this report the main forms of ectopia lentis and their pathophysiology's as well as the current treatments used globally to help alleviate the discomfort ectopia lentis sufferers. It will also include a case report on a child who has ectopia lentis.

Case Report

Master I.R is a 6 year old Caucasian boy from Cumbria. He presented on the 28th of July 2009 at Manchester Royal Eye Hospital, after being referred from his district general hospital. His current prescription was; Right eye: -8.00/+5 Ã- 90⁰ and Left eye: -8.00/+5 Ã- 90⁰.

On examination:

It is found that he has lens subluxation bilaterally, with the right eye being worse than the left. The lenses of both eyes were subluxed superiorly and the bottom halves of the lenses were crossing the visual axis. Visual acuity tests revealed acuity of 6/36 in the right eye and 6/24 in the left. Fundus examination showed no abnormalities and both eyes were considered to have healthy Fundi. A refractive examination of the patient gave the results: Right eye: -10.00/+4 Ã- 90⁰ and Left eye: -9.50/+4 Ã- 90⁰.

On examination the diagram below is noted to show the extent of subluxation:

Left eye Right Eye Iris



Past medical history of the patient revealed that he was born one month premature by emergency caesarean section and he had neonatal jaundice. The mother also revealed she suffered from pre-eclampsia during the pregnancy. It is also noted that the patient has a family history of ectopia lentis; his mother has subluxed lenses in both eyes but to a lesser degree than her son. It is also noted that the mother of the patient had been informed by her GP that she did not suffer from Marfan's syndrome or have any family history of Marfan's syndrome and was slightly reluctant about being seen for a genetics referral. There is also a strong maternal history of myopic astigmatism with many family members being affected. Master I.R also suffers from asthma, but it is well controlled and he has never had any hospital admissions for it.

From this the patient was diagnosed with bilateral lens subluxation (ectopia lentis). It was then decided that surgical lensectomy was needed for both eyes if the lenses were to become further subluxed. After more reviews it was decided that surgery was necessary and surgical lens aspiration for the right eye was organised for the 10th of September 2009.

The patient was then admitted pre-operatively on the 9th of September 2009 and had measured visual acuities of 6/24 and 6/18 in the right and left eye respectively. Master I.R was very anxious on the day of the surgery and had to be calmed down by various staff throughout his pre-operative stay. On the day of the surgery, unfortunately, a mild suprachoroidal haemorrhage occurred and the surgery was therefore stopped. The parents were then informed about a second procedure with a guarded prognosis and agreed to a revision surgery of the right eye. This was organised for the 25th of September 2009. The right anterior segment revision with vitrectomy and peripheral iridectomy was performed on this day without any further complications. After the surgery the patient was prescribed with the following drugs: Acetozolamide, Maxitrol and Cyclopentolate.

Following further reviews of the patient, left eye surgery was organised for the 22nd of January 2010. During the day of this surgery the patient's visual acuity with glasses was recorded at 0.52 logMAR (6/18 Snellen) in the right eye and 0.70 logMAR (6/60 Snellen) in the left. Fortunately the surgery was completed without any major complications and he was prescribed Predforte, Cyclopentolate 1% and Choramphenicol 0.5% for his left eye. On the 26th of January the patient was seen again on clinic and had recorded visual acuity with glasses of 0.42 logMAR (6/18 Snellen) in the right eye and 0.56 logMAR (6/36 Snellen) in the left eye. On examination the both eyes seemed "quiet" and no complications were arising. The final examination to date of this patient on the 4th of February 2010 he recorded visual acuity of 0.38 logMAR in the right eye and 0.40 in the left eye.

Ectopia Lentis


Ectopia lentis is a disease in which the lens is dislocated or displaced from its right position. It was first recognised by Berryat in 1749 and later was named "ectopia lentis" by Stellwag1. The disease manifests from conditions which affect of the zonules of Zinn, causing the lens to be subluxed or luxated within the eye. Ectopia lentis is often associated with other diseases which have many systemic manifestations such as: Marfan's syndrome, Homocystinuria and Weil-Marchesani syndrome1.Lens dislocation or displacement can also occur without systemic associations or from trauma2. This disease can cause a great disturbance to visual acuity when the lens is no longer in the correct position; the greater the displacement, the worse the vision will be3. Currently the rate incidence and prevalence in the general population of ectopia lentis is unknown.

1. Aetiology of Ectopia Lentis.

Ectopia lentis is commonly associated with genetic disorders that affect the zonules of the lens and cause a manifestation of the disease. The main diseases associated with ectopia lentis, as already mentioned, are Marfan syndrome, Homocystinuria and Weil-Marchesani syndrome1. Even rarer disorders which also cause ectopia lentis are sulphite oxidase deficiency and hyperlysinemia1.

Table 1: Causes of Ectopia Lentis.

With Systemic Involvement

Without systemic Involvement


Marfan Syndrome

Familial Ectopia Lentis



Ectopia Lentis et Pupillae

Sulphite Oxidase Deficiency

Weill Marchesani Syndrome


Stickler Syndrome

Ehlers-Danos Syndrome

Source: Adapted from [6]

a. Ectopia Lentis with Systemic Involvement

i. Marfan Syndrome.

Marfan syndrome is a genetic disorder affecting connective tissue which has many systemic manifestations 4. In general sufferers of this disorder have a tall stature, disproportionately long limbs and digits as well as hyperextensibility4. It is an autosomal dominant disorder which is thought to affect an estimated 1/5000-20000 people5. Marfan syndrome results in a mutation on chromosome 15, in specific, the mutation occurs on the fibrillin-1 (FBN1) gene4. The mutation of this gene causes an abnormal expression of microfibrils therefore causing the expression of the disease4. It is said that approximately 50% of Marfan syndrome sufferers have ectopia lentis5.

Fibrillin is a major structural part of the zonules of Zinn and the mutation of the FBN1 gene causes the lens within the eye to be displaced 5. Fibrillin has been found to be secreted from the cilliary body of the eye in the non-pigmented areas but the exact pathophysiology of the disease is not yet definite5. The FBN1 mutation has been found to have a pathogenic effect on degraded fibrillin within the eye and is thought to have some input by metalloproteinases 1 and 35. Although the pathophysiology is not yet clear the expression of the disease causes the zonules of the eye to become stretched and displaced from their correct location, which in turn leads to displacement of the lens.

This condition generally occurs in both eyes and is symmetrical 6. In 80% of Marfan syndrome individuals with ectopia lentis the subluxed lens tends to be superotemporal, although subluxation can occur in any direction6. The zonules in people with Marfan syndrome tend to be still attached and therefore their ability to accommodate is still intact6.

Figure 1: ectopia lentis in an individual with Marfan Syndrome.

Taken from: [3]

ii. Weil-Marchesani Syndrome.

Weill-Marchesani syndrome is a rare disorder also affecting the connective tissue. This syndrome can be found to be autosomal dominant or recessive5. It is considered to be autosomal dominant when the gene mutation is found to be in ADAMTS10 and autosomal recessive when the mutation occurs on the FBN1 gene. In general the appearance of these patients are short in stature, with small limbs and digits and microspherophakia7. It is often described as the opposite of Marfan syndrome7. This syndrome is characterised by a mutation in the ADAMTS10 gene which codes for the A disintegrin and metalloproteinase with thrombospondin motifs 10 enzyme, it has also been found in some cases that sufferers also have a mutation in the FBN1 gene like those found in Marfan syndrome patients8. The ADAMTS10 gene has found to be responsible for the growth and development of the lens, which has its implications on the development of ectopia lentis8. It is also found that the ADAMTS10 has a vital relationship with FBN1 which causes the expression of ectopia lentis7. The ADAMTS10 is found to bind to the N and C terminal halves of the FBN1 gene and this suggests that ADAMTS10 is involved in the making or modification of FBN17. Although this is not concrete the pathophysiology of ectopia lentis will be similar to that of Marfan syndrome7. As the FBN1 gene will have changed in some way due to the faulty ADAMTS10 gene, the expression of the microfibrils within the eye will cause the stretching and displacement of the zonules; therefore conveying the disease ectopia lentis. In this disease the lens often dislocates into the anterior chamber of the eye causing pupillary block glaucoma9.

The lens in Weill-Marchesani syndrome is more likely to be displaced inferiorly and in the majority of cases it is found to be bilateral6. This disease presents in half of cases in the late teens or early twenties6.

Figure 2: Ectopia Lentis in an individual with Weil-Marchesani Syndrome, note the microspherophakia and spontaneous inferior dislocation.

Taken from: [3]

iii. Homocystinuria

Homocystinuria is an autosomal recessive disorder in which there is a deficiency of cystathionine beta-synthase (CBS) enzyme therefore leading to increased accumulation of homocysteine in the serum and increased excretion in the urine10. Individuals with this disease are usually normal at birth but present later on in childhood with failure to thrive and developmental problems11; they also have characteristic features of long slim limbs and arachnodactyly10. This disease, like the previous two, leads to many systemic disorders affecting connective tissue, the central nervous system and the cardiovascular system10.

The ectopia lentis of this disease tends to be inferonasal and usually presents by the age of ten6. The zonules of this disease contain less cysteine therefore they tend to disintegrate and the ability to accommodate is lost6. There is also a higher risk in this disease for the lens to be displaced anteriorly into the anterior chamber12.

b. Ectopia Lentis without Systemic Involvement.

i. Familial Ectopia Lentis

Case report: This is the most likely type of ectopia lentis suffered by the patient in the case report although this is not definite as Marfan Syndrome was not completely excluded. But due to the fact of no other systemic problems of the child this seems like the most likely option.This form of ectopia lentis is an autosomal dominant disorder affecting a mutation in the FBN1 gene, similar to that of Marfan syndrome but without any systemic associations6,11. It is distinguished from other forms by its bilateral and supratemporal symmetrical nature 6. This type of disease may arise congenitally or later on in life6. In the same way that a mutation in the FBN1 gene causes disruption to the zonules of the eye therefore displacing it from its normal location and causing ectopia lentis11.

ii. Ectopia Lentis et Pupillae.

This form of ectopia lentis is a rare autosomal recessive disorder. The main characteristics of this disease are dislocation of the lens and displacement of the pupil in opposite directions of the eye6. The pathophysiology of this disease is considered to be a condition where tethering of the pupil occurs with zonular pathology simultaeneously13. The pupil in this disease becomes oval or slit like in shape because of lenticular and papillary ectopia (same). Clinical findings of this disease are: iris transilluminations defects, axial myopia, glaucoma, megalocornea and poor papillary dilation13.

Figure 3: individual with ectopia lentis et papillae.

Source: taken from [3]

iii. Aniridia.

Aniridia is a congenital disease in which the pupil appears to be missing on superficial examination14. It is sometimes associated with ectopia lentis14. Although the pupil appears to be missing, examination with a gonioscope will reveals an iris root present14.

c. Miscellaneous Ectopia Lentis.

i. Hyperlysinaemia.

Hyperlysinaemia is a congenital autosomal recessive disorder which is very rare and sometimes associated with ectopia lentis6. It is a metabolic disorder which results in a deficiency oflysine alpha-ketoglutarate reductase deficiency6.

ii. Sulphite oxidase deficiency.

This condition is a very rare disorder of sulphur metabolism1. It is an autosomal recessive disorder with associations with ectopia lentis6.

iii. Stickler Syndrome.

This is a connective tissue disease in which there is a genetic disorder in the expression of collagen also associated with ectopia lentis6.

iv. Ehlers-Danlos Syndrome.

This is a group of disorders which are all related by their decrease in tensile strength of their connective tissues15. As already mentioned connective tissues play a vital role in holding the lens in the best position. Therefore this disease will sometimes manifest with and coexist with ectopia lentis15.

2.Complications of Ectopia Lentis

a. Pupil Block Glaucoma.

One of the complications that can arise from untreated ectopia lentis is pupil block glaucoma. This arises from anteriorly luxated lens disturbing the anterior chamber and interfering with the aqueous humour circulation5. The lens can be entirely within the anterior chamber, pushed against the iris or trapped within the pupil, all of which give the same outcome of pupil block glaucoma5.

b. Pigment Dispersion Glaucoma.

This form of glaucoma is caused by the lens and packets of zonules rubbing against the pigmented iris5. It occurs in ectopia lentis as the lens is not held in its rightful position therefore causing pigment to shed from the posterior pigment layer of the iris6. This causes the increase in pressure of the anterior chamber in relation to the posterior chamber and causes the glaucoma to manifest.

c. Refractive error.

The lens in ectopia lentis is no longer in position and therefore an irregular refractive error occurs12. As the lens is out of its usual position light rays tend to traverse it and this causes an irregular myopia and astigmatism12. This also makes it difficult to manage a patient with ectopia lentis as they are difficult to refract and correcting this form of myopia and astigmatism cannot be done adequately 12.

d.Lens-Induced Uveitis.

This is a much rarer complication of ectopia lentis (kanskipage369). This is an autoimmune disorder affecting the eye causing a toxic inflammatory response16 .Uveitis can also occur from direct contact of the lens to the iris or cilliary body again producing a toxic inflammatory reaction16.

3.Management of Ectopia Lentis.

a. Non-ophthalmic management.

If a diagnosis of ectopia lentis is clear then any systemic disorders must be detected and screened for1. A full systemic workup is essential to detect any systemic diseases1.

b. Non-surgical Management.

The main aim of the clinician in the treatment of ectopia lentis is to improve visual functions, evasion or treatment of ambylopia and treatment of any occurring complications17. In most contact lenses or glasses are able to treat ectopia lentis to gain sufficient visual acuity.

When the lens displacement is quite significant and the lens does not interfere with the visual axis, a high powered contact lens or glasses are able to correct the vision in a satisfactory manor18. If necessary pharmacological assistance of papillary dilation may be beneficial so correction of the aphakic zone may be possible11. This is necessary in some cases if the pupil is constricted too much and inhibiting the contact lens or lens of the glasses in refracting the light onto the retina; therefore if the pupil is dilated it will allow this refraction to occur. Yttrium aluminium garnet (YAG) laser treatment can also be used in enlarging the pupil, although it is a surgical procedure it is not intra ocular surgery and would give the same outcome as pharmacological dilation.

In the cases of unilateral or asymmetric ectopia lentis, it is necessary to treat the patient with a contact lens in order to avoid aniseikonia11.

c. Surgical Management.

Surgical management of ectopia lentis involves removal of the lens (lensectomy) and anterior vitrectomy, which is the removal of. There are a number of techniques of lensectomy but they can be divided into pars plana techniques and limbal techniques19. Paediatric ophthalmic surgery comes with more complications and in general is more difficult than surgery in adults due to the more delicate nature of children's eyes. Intraocular lens (IOL) implantation is also sometimes done, although it is not a procedure done in Manchester Royal Eye Hospital, one of the reasons being an increased risk of complications. Complications of both surgeries include: inflammation, infection, sight loss, repeat operation, retinal detachment, glaucoma and failure to improve vision.

Table 2: When should a lensectomy be done?

Indication for lensectomy in ectopia lentis.

Lens in the anterior chamber

Lens-induced uveitis

Lens-induced glaucoma

Lenticular opacity with poor visual function

Anisometropia or refractive error not amenable to optical correction

Impending dislocation of the lens

Source:Taken from[3]

Case report: From this table we can see that Master I.R could have been considered to fulfil one of these categories. His refractive error was gradually getting worse and optical correction was not helping this much. Also from reviews of this boy it was noted his lenses were becoming more subluxed which was contributing to his continual loss of visual acuity.

i. Limbal Lensectomy and Anterior Vitrectomy .

This technique is advantageous because the technique used is more familiar to an ophthalmic surgeon used to anterior segment surgeries than compared with the pars plana approach21. Also the conjunctiva of the eye is not affected and the capsular rim has more chance of staying intact for further IOL implantation later on in life. This technique is the most commonly used technique by paediatric ophthalmologists and it is done bimanually by most surgeons21.

The procedure( in brief below) is under general anaesthetic is done via the following steps:

Two corneal stab incisions are made at 10 o'clock and 2 o'clock using a micro vitreoretinal (MVR) blade making a 1mm incision. These are for insertion of irrigation cannula and aspiration/cutting piece.21

The MVR knife needs to removed carefully in the same plane and direction as it entered and the nondomi-nant hand of the surgeon should make the first incision (left side for right handed surgeon and vice a versa)21.

All instruments must be of the same size to avoid disruption of the anterior chamber depth21.

The non dominant side incision is then used to place an irrigating cannula with a slight turning motion to ease entry into the anterior chamber21.

The vitrectomy handpiece is then placed in the other incision and vitrectorhexis is performed (manual opening of anterior capsule 21.

The vitrector is then placed in front of the anterior capsule without getting too close and facing posteriorly and the anterior capsule is aspirated21.

The vitrector is then used to enlarge the anterior capsulotomy with smooth spiral movements. The desired size is 4.5 to 5 mm21.

Leaving both instruments in the eye, the cutter is switched off and aspiration only continues21.

The aspirating tip is then placed under the anterior capsulotomy and into the equator of the lens in which the peripheral cortex begins to get aspirated21.

Aspiration power should be increased using the foot pedal to maximum power until all of the lens is aspirated21.

The cutter is then turned on and the capsular bag is aspirated into the vitrector21.

A central vitrectomy is then done21.

The two instruments are then removed at nearly the same time, but the irrigation cannula should be removed before the vitrector21.

The incisions are then closed with an interrupted 10.0 vicryl suture21.

Case report: The patient in the case report received a similar surgical treatment of that above although it is not exactly the same it was a limbal procedure. The patient also had peripheral iridectomy in his surgery.Drops of iodine, atropine, steroid and antibiotic are placed on the eye at the end of surgery21.

ii. Pars Plana Lensectomy and Anterior Vitrectomy

This form of surgery is less common for removal of lenses, unless there is a vitroretinal problem in the eye which also needs to be dealt with21. This procedure has the advantage of reducing surgical trauma to the iris and the cornea than compared with limbal lensectomy. On the other hand, the capsular rim is less likely to remain for further IOL implantation in the future than compared with limbal lensectomy21.

The procedure( in brief below) is under general anaesthetic is done via the following steps:

The conjunctiva is opened in the same 10 and 2 o'clock locations21.

The sclera is then perforated at the pars plana level using a MVR knife which is for the vitrectomy probe and the infusion cannula21.

The lensectomy and anterior vitrectomy are then done while trying to leave the capsular sac rim as well as anterior, posterior and equatorial capsule for secondary IOL implantation21.

Turn off infusion before removing vitrectome from the eye which reduces chances of retainl detachment later on in life21.

The inscions are then closed with 8-0 synthetic absorbable sutures21.

iii. YAG Laser Zonulysis.

This technique is used in surgery to move the lens out of the pupillary axis make aphakic correction in that individual11 .This procedure carries a risk of damging the lens, if this was to happen then a lensectomy would have to be organised11.


Ectopia lentis is a challenging disease for a child to deal with and also for an ophthalmologist treat. Although this is the case research is continually improving our knowledge of the disease and people innovating and changing techniques in order to make improve the visual prognosis of ectopia lentis. Having said that, current treatments for ectopia lentis, whether they are surgical or not have a good visual outcome 21. It can be argued that despite the fact that surgery may have a traumatic effect on the child, on most occasions the visual improvement of the surgery is substantial enough to warrant putting a child through it. All in all the current ophthalmic treatments available, in my opinion, are able to give a healthy quality of life which may almost be considered "normal".