|Year : 1983 | Volume
| Issue : 7 | Page : 937-940
Intra ocular implant-a comparative study
S Tony Fernandez
CBM Ophthalmic Institute, Little Flower Hospital, Angamally, Kerala-683 572, India
S Tony Fernandez
CBM Ophthalmic Institute, Little Flower Hospital, Angamally, Kerala-683 572
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Fernandez S T. Intra ocular implant-a comparative study. Indian J Ophthalmol 1983;31, Suppl S1:937-40
A comparative study of various types of lenses-22 Indian made (Shah & Shah) and 8 foreign made-have been done. Intra ocular implant was first started in our hospital in 1978 with the first generation of Shah & Shah lenses but due to some complications it was stopped. 8 cases were done with foreign lenses but due to prohibitive cost, only a few patients could afford it. Interest was revived after the manufacture of better lenses by Shah & Shah and comparative study with this limited number is made.
| Material and methods|| |
Methodology of study: A strict selection of cases was made on the following criteria:
- Only uniocular cataracts were selected for this study.
- Traumatic cataract in young people was also selected.
- No cases with other systemic diseases were taken up.
- Patients with iritis, glaucoma or corneal degeneration were not selected.
- Cases with narrow angle or shallow anterior chamber were not selected.
- Patients with high variable refraction were not selected.
The type of lenses used: 5 different types of lenses were used in these cases.
Details of the patients were included in a specially prepared proforma for this study. In addition to the routine examination, Gonioscopy and A.C. depth were measured. 30 cases which were followed-up regularly were selected. Duration of the follow-up was between 4 years to 6 months.
Most of the younger age group had traumatic cataract in one eye.
All the preparations were done as for a routine cataract operation. It was made sure that the intra ocular tension was low. Finger Pressure method and Balanced Weight method were used to reduce the pressure.
The procedure was as in a routine cataract surgery, but the following special precautions were undertaken:
- All patients were operated under microscope with variable magnifications-Zeiss & Topcon Zoom
- Lenses were implanted under an air bubble.
- In 4 Posterior Chamber Lenses and in 2 Fyodorov Iridocapsular Lenses, extra capsular extraction was performed. In all these cases, posterior capsulotomies were done behind the lens on the table itself
- Sub-conjunctival Dexamethazone 4 mg. with Gentamycin 40 mg. at the time of surgery was given. In 20 cases absorbable sutures and in 10 cases non-absorbable sutures were applied. In all cases atleast 5 sutures were applied.
| Observations|| |
During operation the following were noted:
- Implantation of Anterior and Posterior Chamber lenses were easier as compared to iridocapsular lenses.
- Iris tucking and oval pupil occurred in a few cases of anterior chamber lenses.
- As far as Posterior Chamber lenses were concerned, there was some difficulty in pushing the upper loop. Iris hooks were used to pull the iris upwards.
Inspite of Sub-conjunctival Desamethasone, 10 cases had iritis and iritis with hypopyon by the second post operative day. 4 cases of anterior chamber lenses had mild hypaema which resolved later.
All of them cleared up by the addition of systemic Prednisolone which was tapered off within 2 months.
On long term follow-up the following points were noted:
- Out of the 30 cases, 23 had pigmentation deposits- 16 mild pigment deposits and in 7 higher pigment deposits.
- In one case in which 8.0 Dexon absorbable sutures were inserted, wound leaked and had to be resutured.
- One Iris Clip Lens had dislocated and we had to take it out after 6 months.
From the chart, we find that 21 cases had fairly good vision with minimal power. In 9 cases visual improvement was not satisfactory. Therefore, we did a further analysis of these 9 cases.
Out of 30 cases, 9 did not get satisfactory visual improvement. One case had Retinal Detachment, one case had Macular changes, and one Iris Clip Lens dislocated after 6 months, and it had to be removed. In 6 cases no definite cause was found out except pigmentory deposits on the lens. The fundus was normal in all these cases. We therefore concluded that the non-improvement of vision could be due to pigmentary deposits over the lens.
Iritis: 14 cases had mild to moderate iritis which had to be controlled with systemic cortisone for 2 months. This mild to moderate iritis with hypopion could be due to retained polishing components and microscopic foreign bodies. The food and drug administration had proved with the help of scanning electromicroscope that poor finish of intra ocular lens edges was a significant factor in uveitis, hyphaema, glaucoma, syndrome.
Pigmentation: Out of 30 cases, 23 cases had mild to moderate pigmentation observed through bio-microscope. Out of the 9 cases where vision did not improve. 6 cases had visual loss due to pigmentary deposit. Lens irritation and uveitis might be one reason for pigmentary deposits. Perhaps dark eyed people are more prone to pigmentary deposits.
| Summary|| |
I feel this study is too small a number to make any firm conclusions. Moreover we should follow-up these cases for atleast 4 to 5 years to assess the true success of intra ocular lenses but our experience had been that perhaps Posterior Chamber and Anterior Chamber lenses might be more suitable in our condition because of the easier insertion and least complications. The difficulty in anterior chamber lens is that we should have different diameters in stock to insert the lens.
Inspite of all these complications, is intra ocular implants justified?
With improved quality of lenses and with more experience -of the surgeon, the complications are bound to be less. Only in strictly selected cases, intra ocular implants should be done.
[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5], [Table - 6]