Bilateral Lens Subluxation, in a Pseudoexfoliative Syndrome
Pseudoexfoliation Syndrome (PEX) is a systematic disease distinguished by the production and deposit of extracellular fibrillar material on the surface of several eye tissues and extraocular. The presence of pseudoexfoliative material in the eye affects the prevalence of some issues, such as glaucoma, cataract, lens subluxation, iris atrophy or a keratopathy.
In the eye, the pseudoexfoliation manifests itself as a whitish fine material similar to ¨dandruff¨, that localizes itself typically in the anterior lens capsule, but this deposit also can be found on pupillary margin, lens´s zonule, trabecular meshwork, ciliary body and corneal endothelium.
Pseudoexfoliation Syndrome was reported for first time by the Finnish Ophthalmologist John Lindberg in 1971. It affects between 60 and 70 millions of people around all the world. It is rare before 50 years of age, though from that age its prevalence increments itself very fast. It is more common in women than in men. The prevalence achieves until a 5% in a lot of ancient population, but it is pretty common in Scandinavia and other areas, such as zones of Africa, 25% or superior rates have been reported in members of some ethnical groups with symptomatic cataract.
The factors that lead to development of this illness have not been identified completely. It has been detected a polymorphism of LOXL-1 gene in pseudoexfoliation cases, especially in cases of pseudoexfoliative glaucoma.
Though LOCL-1 gene seems to increase significantly the risk of develop pseudoexfoliative glaucoma, not all the people with this illness will develop glaucoma. PEX is a complex disease and the impact of environmental and climatic factors, North’s latitudes, cold wind, solar light´s hours, among other factors related to the weather conditions, they are also considered in the development of Pseudoexfoliation Syndrome, and however, the evidence on this is mixed.
What are the symptoms and signals?
Clinically, when performing the slit lamp examination, the appearance of whitish material similar to ¨dandruff¨, associated with defects of iris´s transillumination, inadequate dilation of the pupil, instability of lens and corneal endothelium´s anomalies are characteristics very well recognized, but the high risk of develop pseudoexfoliative glaucoma and the incremented risk of complications in surgeries of cataracts are the most important clinic implications of the disease. It has been observed that patients with Pseudoexfoliation Syndrome (PEX) present a higher percent of nuclear and subcapsular cataract, though its pathogeny is not very clear yet. It can have phacodonesis (instability of lens) by zonular weakness, but it is rare the spontaneous subluxation.
How is this disease diagnosed?
The diagnosis of this disease is based in the observation of pseudoexfoliative material in almost every structures of anterior eye´s segment. The exam with slit lamp, which includes gonioscopy and pupillary dilation, represents the gold standard method for the clinic diagnosis of this illness. The Pseudoexfoliation Syndrome is associated to open angle glaucoma in all populations, but with a variable prevalence. In Scandinavian countries, it represents more than the 50% of glaucoma´s cases of open angle. The risk that a pseudoexfoliation syndrome evolves to glaucoma, varies considerably and reaches up to 40% in a period of 10 years. This syndrome is strongly associated to age: it is rare in people under 50 years old and it almost always happens in people older than 70.
Before we go into the case, it is also important have a general knowledge about lens luxation and subluxation in regard to their causes and futures complications.
Lens luxation is the itself total displacement of its normal position (in the middle and form behind the pupil) and it happens because weakness or breaking of zonules. We refer to subluxation when the displacement is partial.
Lens luxation can be classify as congenital (they are produced in embryonic life, and they are diagnosed at the birth) and acquired (they are produced after the birth). Among all the principals causes of congenital luxation or what is the same ectropia lentis, it is found the homocystinuria (bilateral inferonasal lens subluxation), in the Marfan´s syndrome (bilateral and superior lens subluxation) and in Weill-Marchesani´s syndrome (microspherophakia). Acquired lens luxation can be traumatic (it is the most common cause), spontaneous (secondary to other ocular pathologies) and post-surgical.
The spontaneous subluxations are produced by breakings of zonular fibers as consequence of degenerative and inflammatory process, in long evolution´s glaucoma, high myopia, hypermature cataract, retinal detachment, and pseudoexfoliation syndrome, though it is a less common picture, hence the interest of present the next clinic case of a 77 years old male patient, who goes to emergencies of ophthalmology´s service because he presents decrease of bilateral visual keenness accompanied by ocular manifestations. The treatment in these cases will always be surgical.
Clinic case´s exposition
Next it is presented a clinic case of a 77 years old male patient, with sudden decrease of vision in both eyes; through clinic criteria and complementary exams, the diagnosis of Bilateral Lens Luxation because of a Pseudoexfoliation Syndrome was reached.
A 77 years old male patient, with pathologic antecedents of apparent health, goes to ¨Calixto García¨ Hospital´s emergencies after he presents sudden loss of bilateral sight with tree days of evolution, accompanied of severe pain´s sudden appearance in the left eye, without irradiation, persistent; also a bilateral red eye and tearing. Patient refers ocular antecedents of Cataract with 2 years of diagnosis, pending for be operated.
To the physical test the blood pressure 110/80mmHg, temperature 37.9 Cº, heart and respiratory rate within normal limits. On general physical examination the patient is observed irritable, Glasgow 15/15, without dermatological or auditory alterations. Normoline phenotype.
In laboratory exams as complete blood count, biochemistry parameters and elemental exams of urine, they were found within the normal ranges. At the same time, important changes in the brain magnetic resonance were nor found, not even on the standard chest X-ray.
On the ophthalmological exploration the patient presents visual keenness (measured with Snellen chart) of his right eye from counting fingers to 10cm and left eye bulk vision or move of hands to 8 cm; the muscular tone of both eyes were raised to the digit pressure, accompanied of an important ciliary reaction in the left eye.
On the biomicroscopy with slit lamp, alterations were observed, such as:
Presence of corneal edema, pseudoexfoliative material in the pupillary sphincter, lens sublimated in the rising sun phacondonesis and iridodonesis.
Presence of corneal edema, pseudoexfoliative material in anterior camera and pupillary ridge, subluxated lens with anterior displacement respect to the iris.
Ocular moves: Without alterations.
Pupillary reflects: Preserved.
Red orange reflect: Abolished at lower eye level.
Right eye: It is possible to enter with +10 diopters, where normal papillae is observed, excavation of 0,4. Neuroretinal ring that respects the ISNT rule, not nasal ripping of the vessels, no signs of vallotenization, applied retina, not bleeding, not exudates.
Left eye: It can be made in this moments.
Immediately it is indicated to the patient a treatment with Prednisolone eye drops 0,5% 1 drop every 4 hours, Timolol eye drops 0,5% 1 drop every 12 hours in both eyes, and he is dated again in two days.
In the consult the patient refers total disappearance of pain and a slight improvement in his visual status (just with the use of Prednisolone). He is placed in slit lamp and it is observed in right eye, more subluxated lens, while in left eye is observed total luxation of lens, as well as presence of crystalline material floating in anterior vitreous. Eye strain (taken with Goldman´s tonometer) at 11:00 AM with 25 millimeters of mercury (mmHg) in right eye and 28 millimeters of mercury (mmHg) in left eye.
Refraction is indicated with such as result:
RE +10.75 -0.50 x 90 0 (0.6)
LE +10.00 esf (0.6)
These results indicates in right eye a compound hyperopic astigmatism, and in left eye severe farsightedness.
Gonioscopy (Goldman) it is observed up to the band of ciliary body with pseudoexfoliative material in the trabeculum.
Ocular ultrasound in A mode where is noted bilateral lens subluxation to anterior vitreous, applied retina, the same medical behavior is maintained.
Patient who is maintained with follow-up by external consultation every 15 days with actual treatment of, Timolol eye drops 0,5% 1 drop every 12 hours, Dorzolamide eye drops 2% 1 drop every hours and Prednisolone eye drops 0,5% 1 drop every 4 hours. Where he is maintained with digits of eye strain under 21 mmHg and currently pending to be operated for our service.
Being the bilateral lens subluxation a less frequent ophthalmological condition, at the starting point of a Pseudoexfoliative Syndrome and even more in a male patient without antecedents of apparent disease, we did not want to miss out this interesting case that goes to our service of ophthalmology at Calixto García Hospital. In Pseudoexfoliative Syndrome, even when it is not known exactly its source, probably it came from different zones as expression of a diffuse disorder of basement membranes, it can be monocular or binocular with an asymmetric variable grade. Usually the disorder is just clinically apparent in one eye, though the other eye can present the syndrome later. The deposit of this material at zonules´s level (structures that maintained the lens in a correct position) triggers secondarily the partial or total fall.