|Year : 1981 | Volume
| Issue : 4 | Page : 369-376
Aphakic retinal detachment
PK Khosla, HK Tewari, SP Garg
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India
P K Khosla
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Khosla P K, Tewari H K, Garg S P. Aphakic retinal detachment. Indian J Ophthalmol 1981;29:369-76
Incidence of retinal detachment in aphakics (1 to 2.5%) and incidence of aphakia in retinal detachment (7% to 35%) varies and hence it is difficult to establish the actual incidence due to nonhomogenecity of the series reported.
Retinal Detachments in aphakics is unique in some aspects and has got special features for its management and hence prognosis. The purpose of this study is to present a retrospective study of cases of aphakic retinal detachment seen in five years (1972-1976).
| Materials and methods|| |
Retrospective analysis of 138 cases of aphakic retinal detachment who were operated in our centre during the years 1972-1976 were studied, regarding preoperative assessment, operation done and post operative results (anatomical and functional). Emphasis was given to find out the interval between the cataract surgery and onset of symptoms of detachment. We have already reported a study of 416 consecutive cases of retinal detachment operated during this period which form basis for comparison between aphakic retinal detachment and consecutive cases including aphakic retinal detachment.
| Observations|| |
Aphakic retinal detachments formed 38.8% of the total series of detachments [Table - 1] during this period (33.2 % of the operated and 44.7% of the unoperated cases). [Table - 2],[Table - 3],[Table - 4],[Table - 5] give the results of observations with regard to age, sex, type and location of retinal breaks, extent of retinal detachment and anatomical and functional success is this series.
| Discussion|| |
One must differentiate retinal detachment in aphakia as compared to aphakia in retinal detachment. It is difficult to collect a large series of patients operated for cataract with a similar surgical technique and the number of A.R.D. in them tends to be too small for statistical analysis. Stenkula and Tornquist (1977) followed 500 consecutive cases of cataract surgery (84% intracapsular, 16% extracapsulat and needing) for 10 years and found only 9 cases (1.8%) out of which 4 had vitreous loss and 3 had extracapsular extraction.
We are actually reporting aphakia in retinal detachment cases. Shapland (1934) was the first to review 50 cases of retinal detachment which followed either a needling operation or extracapsular extraction. Over the decades series of A.R.D. (aphakia in retinal detachment) have been reported by various authors,,,,,. In our series these constitute 33.2% of the operated cases (138 out of 416). 34.7% of the unoperated and 38.8% of the total cases.
Many author ,,,,, have indicated the influence of old age in the development of rhegmatogenous retinal detachment. The addition of complicating factors as cataract, its extraction and consequent complications add to the development of more cases of retinal detachment in aphakes. One of the parameters in evolution of cataract may be high myopia as highly myopic eyes show higher prevalence of cataract and myopia in itself is a predisposing factor for retinal detachment so the incidence of retinal detachment in aphakes will be more than otherwise comparable group and this should mean less number of myopes in the prone age group without cataract. However, this is not borne out by facts as found more myopes in phakic group than in aphakic group. Stenkula and Tornquist (1977) found a lower incidence of myopes in A.R.D. in unselected group. Hence the role of myopia is likely to be the same in cataract prone group as compared to other groups.
The role of operative technique and complications (operative or postoperative) in A.R. D. has to be considered. Intracapsular extraction used to be considered more dangerous due to mechanical trauma although it is not borne out by facts. Nonnenmacher (1951) blamed extracapsular extraction more although the cases reported were high myopes. Stenkula and Tornquist (1977) also concluded that uncomplicated intracapsula r is probably not more dangerous. Vitreous loss at the time of cataract extraction materially alters the static and dynamic state of the eye and should basically cause different type of retinal detachment than when lens is removed without complication. It seems that latter may not be significantly changing the state of eye as far as retinal detachment is concerned although it may be exposing the already present weak retinal areas to give way. However vitreous loss and haemorrhage increase the risk of massive vitreous retraction and hence the chances of retinal detachment in aphakics. When the interval between cataract surgery and onset of retinal detachment is short, it speaks of operation being an important cause. In our series, 36.2% occured in first six months. Various authors report that 32.2% to 66% of detachments occur within six months after cataract extraction.,[,,, The cases where complication like vitreous loss occurred after intracapsular lens extraction constituted about 10.8% and in such cases detachment occurred within 6 months of surgery. Most of the cases of traumatic cataract showed detachment with in 6 months. It is thus emphasized that retinal detachment may be present before cataract extraction particularly so in cases of trauma and may come to notice only after cataract surgery as it may increase due to dynamic changes occurring in the chambers of the eye. In 65.2% of our cases detachment developed during the first year of cataract extraction which tallies with other authors,,. There was no significant difference in detachments occurring after intra and extracapsular extraction when there was no complication and these occurred mostly within a year but mosly after six months. After the first year the incidence of aphakic retinal detachment fell in our series dramatically i.e. another 18.8% upto 2 years while it was only 8.7% between 2-5 years.
However, after 5 years, of cataract surgery only 7.2% cases were seen and in all these there was history of repeated needling so we feel that detachment occurs in cases where needling is done only after 2 years.
In our own series most (76.9%) of our patients were above 50 years of age, cases were negligible (1.4%) in pediatric age group (upto 12 years) while not very significant (4 9%) between the age of 13-20 years. Some cases (18.8%) were seen between the age of 20-50 years. (Ashrafzadeh et al (1973) reported higher average age in A.R.D. cases but probably is due to exclusion of cases below 38 years of age, nonsenile cataracts and cases with history of trauma.) In age group higher than 67 years incidence of A.R.D. was significantly greater than P.R.D. indicating that aphakia may be a factor in accentuating the retinal detachment process.) The patients under 35 years of age in our series who developed retinal detachment were either of congenital cataract who were operated by repeated needling or were cases of traumatic cataract who might have had associated detachment due to trauma and interestingly both these groups were in males.
Males preponderate in retinal detachment cases and some authors, have shown incidence of males to be greater in A.R.D. than in P.R.D. although Ashrafzadeh et al (1973) did not find statistically significant difference. The incidence of males in our A.R.D. series (76%) was more as compared to other series,. As cataract affects both sexes equally the higher proportion of males in A.R.D. may indicate involvement of some other factor (trauma as males are more prone.) This male preponderance may well also be due to higher hospital attendance of males due to socioeconomic reasons-males being the wage earner. If we analyses our series further [Table - 2] the percentage of males over females of cases in age groups above 35 years was a little higher but females were conspicuous by their absence below this age group presumably due to less incidence of trauma so preponderance in males in overall series may be fallacious.
Since Gonin pointed out the importance of retinal breaks in retinal detachment, form, number and localisation of breaks have received great attention. Morphological characteristics of retinal breaks in A.R.D. are round or oval holes particularly in upper nasal quadrant, horseshoe or irregular tears and dialysis but Menezo et al (1977) have reported 10 different types adding finger nail tip like breaks, microholes clusters or pebbled holes, double horseshoe tears and oral tears. We have stuck to the classical descriptions. In our series no definite break was found in 26 cases (18.8%) which is higher as compared to other series,,, suband may be due to the fact that most cases come to us as total detachment. However, Pasino and Santore (1967) have reported undetected breaks in 40% of aphakic eyes.
Distribution of breaks have been studied by various authors ,,, and it was indicated that number of breaks are higher in aphakic eyes. (Menezo et al (1977) reported single break in 30.4%, 2 breaks in 24.5%; 3 breaks in 20.6% and 4 breaks or more in 24.5%) We have found only a single break in 44.2% which compares well with Ashrafzadeh)sub et al (1973) - 42.5%.
Horseshoe tears have been reported in 44.2 % subto 59.4%. In our series most of the cases with single horseshoe tear (44.2%) were after uncomplicated intracapsular extraction and the other eve in most cases was myopic with lattice degeneration. Round holes in quadrants other than upper nasal were seen in 16 cases (11.5%) and these were associated with bilateral lattice degeneration. Ashrafzadeh et al (1973) conclude from presence of more round holes as also reported by that there is significantly higher frequency of retinal atrophy and lower incidence of vitreous traction but it seems fallacious as 59.4% of their cases showed horseshoe tears which is an indicator of vitreous traction and also report that the defference of incidence of horseshoe tears from P.R.D. was significant. These cases along with those which had a single horseshoe tears were put by us in the phakic type of A.R.D.
Round holes in upper nasal quadrant or near ora are said to be characteristic of A.R.D. and may be related to insertion of zonular fibres and their breaking during cataract extraction. We saw these only in 16 cases (11.6%) and hence do not attach more significance to these dialysis or giant retinal tears (4 cases-3%) Ashrafzadeh et al 1973 only report 0.7%) or irregular tears (15 cases-10.9 %) were seen in cases where there was vitreous loss during intracapsular surgery and vitreous was seen incarcerated in the corneal wound. We term these as aphakic type of A.R.D.
Hence A.R.D. shows two distinct type of groups-one in which type of breaks are similar to phakic retinal detachment (Phakic type A.R.D.) and other in which they are significantly different (aphakic type A.R.D) and prognosis in the later is poorer.
In our series, more breaks (more than 60%) were found in upper temporal quadrant. Only 11.5% showed breaks in upper nasal quadrant and negligible in lower nasal quadrants. Norton (1964) however, did not find a statistically significant difference in supranasal and infranasal breaks, atthough other authors, report similar involvement of nasal quadrant. Ashrafzadeh et al (1973) report incidence in temporal quadrants as 78.7% in A.R.D. and 96.7% in P.R.D. in nasal quadrants 65% in A.R.D. and 50.6% in P.R.D. The retinal breaks were significantly greater in temporal than nasal quadrants so we do not support the contention that breaks in nasal quadrants are more than temporal quadrant in A.R.D. although the nasal quadrants may be involved more in A.R.D. than in consecutive cases.
The detached area in A.R.D. is larger than P.R.D. in first presentation as it may progress faster and we support the contention as most of our cases presented with subtotal or total detachments. 66% presented with subtotal detachment i.e. extending more than 180° which is nearly the same (62.2%) as by Stenkula and Tornquist (1971). Total retinal detachment was seen in 40 cases (29%) who were operated-(the cases which were refused surgery by us were mostly with total detachment and defective projection so the figures by other authors,, may not be comparable.) Only 7 cases (5.08%) presented as detachment localised only to one quadrant associated with a single horseshoe tear and this is compared favourably with others,.
Prognosis in aphakic retinal detachment is poorer both anatomically and functionally as compared to phakic retinal detachment,. The additional causes may be cystoid changes in macular after cataract surgery, operative vitreous loss or postoperative vitreous haemorrhage with consequent M.V.R., missing of breaks particularly small oral holes either due to lenticular remnants or vitreous strands preventing exact ophthalmoscopy. Ashrafzadeh et al (1973) reported that macular involvement in 83% (65.1 % in P.R.D.) inspite of the fact that more breaks are located nasally in A. R. D. and fixed retinal folds in 54.7% (39.3% in P.R.D.), All cases presenting as subtotal or total detachment (95%) had macular detachment so we agree that prognostically these cases are poor.
In our series anatomical success was 76% whereas functional success was 65.2% and both are lower (81% anatomical & 77.4% functional) as compared to bigger series of consecutive cases but are comparable to others,. Encircling procedures are thought to be more advantages and we have used them as a routine apart from cases where only one quadrant was involved. Norton (1964) however, has reported success in 85% (89% in P.R.D.) and does not think that A.R.D. has a poorer prognosis. Prognosis is still poorer in aphakic type of A.R.D. (72% Anatomical & 59% functional) than the phakic type of A.R.D. (73.2% anatomical & 70% functional) due to different intraocular state due to vitreous loss as already discussed.
There may be different pathogenesis in A.R.D. as compared to phakic retinal detachment. It is known that force of adhesion between retina and pigment epithelium is loose at death and it is surmised that conditions which disturb physiological balance of eye may affect this force and hence this adhesion by corolary may be loose in aphakes. Ashrafzadeh et al (1973) believe that force of this adhesion may be more important in causing A.R.D. than vitreous traction and support their contention by presence of more round holes indicative of atrophy and lower incidence of horseshoe tears with roller edges indicative of traction, but we do not support this as traction after vitreous loss plays a significant role and presence of horseshoe tears is indicative of traction in its pathogenesis. We believe that A.R.D. is of two distinct typesPhakic and Aphakic. The significant increase of vitreous changes due to operative vitreous loss and postoperative vitreous haemorrhage in certain cases leads to what we call aphakic type of A.R.D. apart from cases where round holes are found in upper nasal quadrant and rest of the cases which are no different from P.R.D. are labelled as phakic type of A.R.D. and this latter group may be having more retinal detachment due to changing dynamics.
The characteristics of aphakie retinal detachment which emerge are (i) more common in males (ii) more cases of undetected breakes, (iii) more breaks nasally than P.R.D. (iv) more M.V.R. (v) more incidence of total retinal detachment.
| Summary|| |
Cases of aphakic retinal detachment selected from a retrospective study of primary retinal detachment presenting to us from 19721976 have been analysed. Time interval between cataract surgery and appearance of retinal detachment is within 6 months in cases where there is vitreous loss, within 1 year (at the most 2 years) in cases of uncomplicated cataract extraction while it is always above 2 years in cases where repeated needling is done. On the basis of this study we believe that aphakic detachment can be grouped under two big types-Phakic type (not different from usual cases) and Aphakic type where vitreous loss or postoperative vitreous haemorrhage as such plays a major role. Prognosis in latter variety is poorer.
| References|| |
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[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5]